I took my 75 Bronco with a 398W to the dyno today and was sorely disappointed with what it put out:

http://i177.photobucket.com/albums/w229/recoiljunky/Mobile%20Uploads/SNC00387.jpg

I'm running 9.5 to 1 compression, Edelbrock Performer RPM heads with 2.02" intake valves, and Comp Cam X4262H cam. Here's the specs on the cam: http://www.compcams.com/Cam_Specs/CamDetails.aspx?csid=884&sb=2

I'm running 36x12.50 TSLs with 4.56 gears, NP435 and a D20.

I had started another thread about swapping the intake out. Right now it has an Edelbrock Performer on it, but I have a RPM Air Gap sitting on my work bench ready to go on. I'm going to try putting it on and seeing how it changes my numbers. I will use the same Holley 660TA that's on it now.

What do y'all think? Set the damn thing on fire and start from scratch? I've really got a lot invested in this motor for it to be bringing these numbers. I would have thought that the numbers would have been much higher based on the seat of the pants meter. :confused:

Oh yeah, I guess I should have started the test at a much lower rpm as I missed most of the picture.

That is one hell of a lean spot at 2500-2700rpms. Then starts getting fat after 3k.
You have to remember you are going to drop anywhere between 20-30% through your drivetrain, plus you are running larger tires than most trucks will dyno with, and gears. I bet if you put a set of 31" tires on and dyno it again, your numbers would jump quite a bit.
Just remember, a dyno is only a tuning tool, different dynos and even operators will put out different results. You might go somewheree else and it might be a 10% difference in numbers.
Going through a 4x4 drivetrain, and running that big of a tire on the dyno, your torque looks great. I would be pretty pleased with that myself.

EDIT: Also did you do more than one pull? Try adjusting timing, carb, jets? Or was it just a few pulls to get a baseline?

I'm guessing that lean spot is where I was hitting it. The carb opened up but the accelerator pump wasn't pumping enough fuel. I have since changed the cam position on the accelerator pump. I think I need to go up to a larger squirter too.

That was the best of three pulls, no adjustments in between.

am I seeing 202hp at the wheels? I bet you are loosing closer to 30-40%.


I have been in a buggy making a dynoed 250 RWHP with 39's. That thing fawkin rips!!

x2, you lose at least 20% through a stock drivetrain and tires.

I have 2004 5.3l in my jeep dyno'd it with 37's and 5.13's at one point. The motor is supposed to be 330hp rating and it did 214hp at the wheels. feels good, but thought it would be more as well. People are telling me the same as you are hearing.

That's all good to hear.

How about the curve? Seems pretty flat, no?

told you it would be low - you still have the performer on her ?

the drivetrain loss can vary from 20-45%. autos are almost always near 35%. you are most likely making just over 300hp - loose the intake. play with the accel pump for the tip in. it also looks too fat - for a non blown unit wide open should be around 12.5 . looks to me like it needs a jet or two smaller and possibly some more timing - what are you at now ? 36 -38 total ? and a 660 cfm is fine for your rpm range and cubs.

those numbers are a bit low, the thing that stands out to me besides being fat from 3200 up is how low the peak torque is, irregaurdless of the number it appears as if it peaks by 2200 and drops off from there, dude, you have a breathing problem, the cam is too small for the stroke, the intake is too small, the carb is prob o.k., check manifold vacuum at wot, anything over 2" indicates the carb is too small, you should shoot for peak toque near 3500 or so, your hp numbers will improve alot.
a 351 i did that was low budget had ported 69 windsor heads a comp extreme 274 cam, a edel performer with a 650 d.p., on a mustang dyno it made 360 at the tires through a c-4 with a 2400 stall..

i bet with the other intake and some AF tuning you will see the hp climb a little faster and not fall off after 4k. dont expect 50 hp at the tires. but i could see 20 -30hp possible

it also looks like your peek tq would have been higher if you didnt have the lean tip in.

told you it would be low - you still have the performer on her ?

the drivetrain loss can vary from 20-45%. autos are almost always near 35%. you are most likely making just over 300hp - loose the intake. play with the accel pump for the tip in. it also looks too fat - for a non blown unit wide open should be around 12.5 . looks to me like it needs a jet or two smaller and possibly some more timing - what are you at now ? 36 -38 total ? and a 660 cfm is fine for your rpm range and cubs.

You called it.

I'll start swapping the intake tomorrow. I'll have to mod my hood to get it to close.

What would you suggest for the accel pump, going up two sizes?

IIRC, I've got it set at 34 degrees total timing. I've been scared to add more because I can't hear if the motor is pinging or not, I'm running side exit exhaust that's loud.

those numbers are a bit low, the thing that stands out to me besides being fat from 3200 up is how low the peak torque is, irregaurdless of the number it appears as if it peaks by 2200 and drops off from there, dude, you have a breathing problem, the cam is too small for the stroke, the intake is too small, the carb is prob o.k., check manifold vacuum at wot, anything over 2" indicates the carb is too small, you should shoot for peak toque near 3500 or so, your hp numbers will improve alot.
a 351 i did that was low budget had ported 69 windsor heads a comp extreme 274 cam, a edel performer with a 650 d.p., on a mustang dyno it made 360 at the tires through a c-4 with a 2400 stall..

Thanks for the advice.

When you say check manifold vacuum at wot, you're talking about with the transmission in neutral, right? Like, blip the throttle and make sure the vacuum bottoms out?

id run the total timing up to 36 - what fuel are you running ? when does the timing come in ? the carb has a single accel pump right ? id do two sizes. also after your first pull try to get the AF near 12.5-13 under WOT. most likely 2 jet sizes - do the secondary jets first.


as the vaccum i do it under a light load

id run the total timing up to 36 - what fuel are you running ? when does the timing come in ? the carb has a single accel pump right ? id do two sizes. also after your first pull try to get the AF near 12.5-13 under WOT. most likely 2 jet sizes - do the secondary jets first.


as the vaccum i do it under a light load

I'll try bumping the timing up more.

93 octane.

Timing comes in early, around 2k. I only have one light spring in my Duraspark dizzy.

Yep, one accel pump. I've got the stock accel cam in the #2 position. It was in #1 for the dyno run.

I'll get a couple new jets too.

That cam is wussy too.

Like what was said in the other thread... your cam is tiny for the flow of those heads, and your intake is a cork. You said you didn't want to swap the cam, so do the intake and get it tuned the best you can.

manifold vacuum at wot at max engine speed, if it can pull 2" or more vacuum, the carb is the restriction, but, you would be making more power on 660 cfm to bottom out the carb, the biggest problem you have is the cam, a 262 is a stock rv type grind in a 306 let alone a 393..
also the squirter issue, usually you will find it needs a different pump cam before a squirter change (if it's a .028) make sure the secondaries are opening and you have full throttle aswell, seen that a hundred times..

just played with this combo in the dynosim, if your runing manifolds still it says 300/425, peak torque at 3500 rpm, with a stick trans you should only see a 15-18% drop at the tires, i would want to see 245 to 260 at the tires, it doesn't look like it will pick up much with the intake man, maybe 10-15 at best...

put 302 parts on a 351w (or stroker) and you will get 302 power.

strokers need to breathe.... A LOT. Don't be scared to cam that thing. A custom cam will make a world of difference. Ed Curtis comes to mind. That thing should be a torque monster if you can fill the cylinders.

with a stick trans you should only see a 15-18% drop at the tires,
Car type manual yes... like a T5... but the truck granny trannies eat power. Nowere near as much as say a C6, but alot still. Combine that with big heavy tires, a 9", and a gear driven TC and the drivetrain losses are huge. Throwing some stock rollers on it for the next trip will probably help quite a bit.

I agree that motor needs intake and cam. Alot more cam. What you're running now may be decent in a 351 but its a grandpa RV cam in a stroker. Which is fine if you're just going for low end.

I'm still thinking I don't want to pull my cam, but if I did, does anyone want to suggest another cam?

I don't want to lose a significant amount of low end grunt.

Car type manual yes... like a T5... but the truck granny trannies eat power. Nowere near as much as say a C6, but alot still. Combine that with big heavy tires, a 9", and a gear driven TC and the drivetrain losses are huge. Throwing some stock rollers on it for the next trip will probably help quite a bit.

I agree that motor needs intake and cam. Alot more cam. What you're running now may be decent in a 351 but its a grandpa RV cam in a stroker. Which is fine if you're just going for low end.

yeh, opinions vary on this and rotating mass uses power, but, a man trans in 1:1 into a t-case in 2wd, into a 9" ford rear, geared, with 36" ,isn't going to eat much power, no more than a superduty with a locked torque convertor, which is like 20%, hey, that why i used to call the dyno "reality check," we can agree to disagree.. hell, it might be the cam is degree'd wrong, shitty exhaust, etc...

I ran your combo in comp cams camquest software. Here is your combo, your combo with an rpm airgap, and airgap plus more cam. I'm guessing you have headers with your side exit exhaust... but it gives you an idea anyway..

I really do appreciate all the advice, especially the number crunching.

I'm swapping the intake this afternoon. I've spent the past couple of hours working on the tip in without a whole lot of luck. I swapped from a 28 to a 31 squirter. The off idle stumble seemed to improve. I swapped the stock orange accel cam for the slightly bigger blue cam, I think it got worse. I think I have the accel linkage adjusted right. I tried the blue cam with the 28 squirter. Still bad. I guess I need to go back to the 31 with the orange. Maybe a 32 with the orange.

cant see a small intake, small plenum, small cam motor needing that much accel pump, your timing is probably coming in too soon, check with a timing light and see how soon it comes in, all in by 2800 should work fine on that, any sooner and you will have issues..

I guess I'll give this a try:

http://i177.photobucket.com/albums/w229/recoiljunky/Mobile%20Uploads/SNC00394.jpg

Still need to clearance the hood.

cant see a small intake, small plenum, small cam motor needing that much accel pump, your timing is probably coming in too soon, check with a timing light and see how soon it comes in, all in by 2800 should work fine on that, any sooner and you will have issues..

But would screwed up timing affect my A/F graph? The graph shows a definite lean spike right when I open the carb up.

sure - if the timing in all in at 2k then its leaning out due to when the combustion occurs. it can also lead to a hessitation - all in like weave said at 2800 would be ok. your rig isnt heavy but only one light spring for the advance might be to light

yeh, what rollin said, basically the more retarded you are the fatter it will be, if you advance the timing with the same jet it will lean out the engine, usually i end up with a orange pump cam, .028 squirter, ignition about 36 total with it all in by 2500-2800, this is a very good starting point for that engine, if you do have only one spring in the dizzy you are prob all in by 1400 rpm =bad... this might explain your lack of power, if the pressure rise in the cylinder is too early it fights itself/detonates and kills power and throws off the a/f ratio..

yeh, opinions vary on this and rotating mass uses power, but, a man trans in 1:1 into a t-case in 2wd, into a 9" ford rear, geared, with 36" ,isn't going to eat much power, no more than a superduty with a locked torque convertor, which is like 20%, hey, that why i used to call the dyno "reality check," we can agree to disagree.. hell, it might be the cam is degree'd wrong, shitty exhaust, etc...Honestly i only have one example to go by- years ago a buddy of mine had a local engine guy build/tune a 383 SBC for his older blazer. The engine guy dyno broke the motor so it would be just a bolt in deal and IIRC it was 400 at the crank. In the truck, with a 465/205 12bolt and 35x15.00 swampers it put out 280-ish rear wheel with nothing changed other than bolting it in.

It could have been a fluke, it could have been change in exhaust, it could have been dyno variances, hell it could have been the friggin humidity. :p This is why i dont really like dyno numbers.

totally, it's a tuning tool, usually dynojets read high...

Is there not a possibility of error regarding the calibration of the dyno or the possibility of operator error? Every ride I saw there produced suspiciously low numbers.

try to get some cool air into that engine too.

hot under hood air sucks for making power.

you might be able to get away with the small cam if you add some 1.7:1 rockers on it, 2.02 valves are huge for a somewhat small ford.

hmm, the cam is wrong for sure. dont be afarid to throw a cam in it, im runing almost .600 lift in a 408w and it loves it, the heads are too small for a 398w, but there on there now. the carb is way to small. talk to patrick at prosystems.com, best carb guy i know. heres what i would try
cam-http://www.summitracing.com/parts.aspx?sku=CCA-35-250-4
carb-http://www.prosystemsracing.com/proseries4150.html
intake- run the air gap
9.5 compression??? go with the smallest head gasket you can find. 10-10.5 is great for pump gas.

Is there not a possibility of error regarding the calibration of the dyno or the possibility of operator error? Every ride I saw there produced suspiciously low numbers.

Absolutely, like I was saying before, it is only a tuning tool. Get the dyno for an hour and bump your timing on there to see where it likes it. Bring a couple extra jets, etc. Once you get it to max out without any detonation, back it off a couple and then you know you are tuned correctly, that is all it is really meant for. Numbers are just a reference to go off of.

As far as drivetrain losses, you can bet it is over 20%. We took a stock LS1 in a 98 camaro, put a D&D built T-56 behind it, spec stage 3 clutch, through the stock rear with 26" tires, the best lubes money can buy and it was still a 13% drivetrain loss. Of course on a different dyno it very well could have been 15%. You are going through an old trans, a trasfer case, a 9" rear(I think that was mentioned), which are known to suck power, trying to turn larger rubber, etc. You are probably at 25-30% A stock vehicle with an auto is usually around 20%. You are nowhere near stock.

The torque curve being flat is actually nice, it will just keep pulling. Although it would be much nicer if it curved up a little. You don't want a ramp, just a nice flat climb. Unless you are planning on drag racing it or mud runs or something like that. Where you can have a giant peak and just shift right after it and be right back in the torque. For what most of us do with our rigs, a flat curve is better. As that goes, it does look like you are restricting the motor in the upper RPM's somewhere. You want more air in the upper RPM's without sacrificing too much down low.

Hope that helps a little.

those numbers are a bit low, the thing that stands out to me besides being fat from 3200 up is how low the peak torque is, irregaurdless of the number it appears as if it peaks by 2200 and drops off from there, dude, you have a breathing problem, the cam is too small for the stroke, the intake is too small, the carb is prob o.k., check manifold vacuum at wot, anything over 2" indicates the carb is too small, you should shoot for peak toque near 3500 or so, your hp numbers will improve alot.
a 351 i did that was low budget had ported 69 windsor heads a comp extreme 274 cam, a edel performer with a 650 d.p., on a mustang dyno it made 360 at the tires through a c-4 with a 2400 stall..

Running your vehicle on a chassis dyno is far better than an engine dyno. Believe the numbers they are what they are. The only way to see how much power your losing is to run it both ways, one with the larger tires and another with the small meats. There are too many variables between the motor and ground to be exact you could spend all day talking about the different possibilities. On my 2005 SD I lose 50-75 RWHP from 40"s-35"s. That's just at the wheels, so when it throws down 491 a the rear with 35"s yet 430 with 40"s, that means I'm somewhere over 550 at the crank, but really all that means is I'm putting a ton of power through my tranny. The RWHP #'s are the ones that matter. Now when you get into the world of chassis dyno there are a lot of Obama types that add corrections into their runs too and thats BS. The number is what it is. Everyone should just be honest if their numbers are RW, corrected RW (Estimated Crank) or engine dynoed. An engine dyno is a true number and so is a chassis dyno. One tells you how much power your motor makes and the other tells you how it performs. You should make as many passes as possible on a chassis dyno to find how how and where your setup runs strongest and what gears to run it in. I spent about a half an hour on the dyno with my '03 SVT powered buggy and in high high with 42"s it only put down about 215 rwhp. who cares that's doing 55-70 down the freeway. To maximize the number I had to run it in middle ratio (C6 to Stack 3 Speed) and 3rd gear and it jumped to 275. That great cause thats where I'll be running it when I need the power and off road. Oh and backing the numbers out it's right in the ball park of where it should be and that's a factory spec motor. 380-400 HP Estimated at the crank.

YouTube - Ford Buggy 4.6 Dyno Run '03 Cobra Mustang 275HP (RW) EB Early Bronco on 42"s (http://www.youtube.com/watch?v=KuSwwYbF_qk)
YouTube - 6.0 Ford Powerstroke 443 RWHP dyno on 40s FUEL ONLY NO CORRECTIONS (http://www.youtube.com/watch?v=HrAl5UTxvGA)
YouTube - '05 on 35's 491RWHP (http://www.youtube.com/watch?v=GQqDCbAzNsY)

you will see that variation on non-eddy current dynos which is what you have run on in those videos, if you decrease the tire height you put more effective gear ratio at the drum, same with deep axle gears, the eddy current controls the rate of acceleration of the drum and factors that torque into the rwhp factor, dynojets don't have this, hp is measured by uncontrolled acceleration of a known mass and converted into hp, to cheat the dyno you can skew the rpm pickup and whalla, the hp changes...

you will see that variation on non-eddy current dynos which is what you have run on in those videos, if you decrease the tire height you put more effective gear ratio at the drum, same with deep axle gears, the eddy current controls the rate of acceleration of the drum and factors that torque into the rwhp factor, dynojets don't have this, hp is measured by uncontrolled acceleration of a known mass and converted into hp, to cheat the dyno you can skew the rpm pickup and whalla, the hp changes...

The mustang dyno (in the 1st VID) kinda does that, and the correction can just be added in prior to pulling by just typing a percentage of correction in which a lot of people do but don't specify when gloating about their numbers. I just wanted to let him know not to worry about the low numbers on the chassis dyno with those size tires and let people know a lot of times they hear people running their mouth about their numbers, why they are full of shit.

Test drove it with the RPM Air Gap. It definitely breaths better. It feels like it's making more torque, more HP and it raps up higher quicker. With the old intake I would shift at 5500, now it goes over 6k before it gets the shift.

It's still not tuned right though. I was getting a little break-up/stumble at the lower rpm range while WOT. I checked my timing and I had 13 degrees at idle (600 rpm) and 30 at 2500 rpm. Advance maxes out at about 38 around 3000 rpm.

I retarded the timing a little bit and adjusted the idle mixture to smoothest idle. On my test drive the break-up/stumble seemed to move up in rpm.

I got frustrated and put it up.

I was running a .028 discharge nozzle, so I upsized to 31, 35 and ultimately to 37 with the 50cc pump. It runs MUCH better. Now it has the slightest bog about the time the pump shot should be running out. I suspect I need to swap pump cams to one that puts more of the shot at the beginning. I'm running the blue one right now.

I guess with my bigger displacement, small cam, big heads and high flow intake a need the big pump shot.

:eek: dude, thats a HUGE pump shot for that engine or anything for that matter :eek: somthing is wrong wit' her son... ;)

:eek: dude, thats a HUGE pump shot for that engine or anything for that matter :eek: somthing is wrong wit' her son... ;)

I'm so green, I can't figure out if you're yankin my chain or being sincere. Is it really a big pump shot? I thought it was, which is why it's taken me so long to try the big squirter and pump.

The motor pulls about 16" of vacuum at idle, if that makes a difference.

seriously, thats huge, a 50cc pump is whats on a dominator, a .037" shooter is ginormous, and a blue cam, fawk, sumpins' wrong dude..
float level, cam timing, something....

Major problem. I think we ran a pump shot like that on a sprayed 502 and it was rich.

FWIW not really related but i think you're vacuum is a tad on the low side considering your cam.

Arrggg!!! I'm gonna set the pos on fire!

It was running better than ever with my huge-ungous squirter and pump and I tried to tune it a little better. I checked the timing and it was a little too advance so I backed it down, reset the idle mixture and took it for a spin. The break up is back. WTF?!?

I'm at 13 BTDC at 650 rpm, 20 btdc at 2000 rpm, 30 btdc at 2500, 35 btdc at 3000 (the last 5 may actually come in a little sooner, but I was checking it by myself.)

From a dead stop, if you hit the gas hard and ride the clutch just a little bit before giving it full engagement it will sharply break up, bucking like a horse. If you ease into it a little bit it won't break up.

I've tried a couple different carbs with the same specs and same results.

Ideas?

I'LL JUST HEAD OVER AND WHIP IT FOR YA'
seriously tho', went back and looked at your dyno chart, your torque is falling past like 2200 or so, if the timing is what you were running on the dyno and the main jet hasen't changed you know two things, it has enough fuel and enough timing, shure it needs tuned, but, something is way off here, i'm bettin the cam timing is off, did you do a compression test?

I'LL JUST HEAD OVER AND WHIP IT FOR YA'
seriously tho', went back and looked at your dyno chart, your torque is falling past like 2200 or so, if the timing is what you were running on the dyno and the main jet hasen't changed you know two things, it has enough fuel and enough timing, shure it needs tuned, but, something is way off here, i'm bettin the cam timing is off, did you do a compression test?

The timing and the main jets have not changed since the dyno.

I've never done a compression test, but the motor is new from top to bottom.

I lined the two little dots up when I but the timing gears and chain on. I have also verified that the number 1 cylinder is at the top of its throw when the timing pointer is at 0 BTDC.

I checked the valves a few weeks ago and they were all set as per the Comp Cams rocker instructions.

The motor cranks very quick and maintains good temperature.

My problems seem to go away when I advance the timing a lot.

Thanks again for the help.

was it a multi-index chain or just one keyway slot in the crank gear

was it a multi-index chain or just one keyway slot in the crank gear

From the website:

Feature induction hardened cast iron camshaft gear and billet steel crank sprocket

• 3 keyway crank sprocket for 4-degree incremental adjustability, 4-degree maximum advance/retard

• Heavy-duty, heat-treated true double roller timing chain; chain available separately

• Ideal for mild street performance applications

I don't think I like where this is going. I'd like to think I was carefull in being sure that I went with the no advance / no retard setting.

seen this alot, and every time people swear they did it right too, i fawked up my first engine chain setup back in the day, i cant think of any other thing that would make that peak torque at 2200 rpm except restricted exhaust.. fawk, stock they peak higher than that...

seen this alot, and every time people swear they did it right too, i fawked up my first engine chain setup back in the day, i cant think of any other thing that would make that peak torque at 2200 rpm except restricted exhaust.. fawk, stock they peak higher than that...

So if it were you, you would pull the timing cover off?

My exhaust is far from restricted; over the frame headers, 2 1/2 collectors, spintech mufflers and exits infront of the rear tires.

i would do a comp test first, but, it looks like your narrowing it down
1. timing is good
2. has enough fuel (a little rich)
3. intake and carb airflow is adequate
4. exhaust is good
5. cant blame the cubic inches (sealed up good, no blowby)
6. you've checked the valve adjustment

basically if your ignition is strong (nice blue spark) you've narrowed it down to cam timing or lobes going flat, something like that, personally, i would change the cam out while i was in there too...

10/4

Regarding the ignition, I'm running the same new Duraspark control module as I did with my old 302 and the 302 ran like shit too. Of course they both also shared the same 35 year old wiring. I'm also running a new coil.

Is there way to quantitatively check my spark? I've seen it spark at the plug, but I'm not sure it makes a "nice blue flame." I wouldn't want to stick my tongue to it, but I don't have anything to compare it to.

well, take an old plug, preferrably a 13/16" variety and remove the ground strap, now it has to jump 3/8" or so to ground, stick it in the coil wire lead and ground it, crank it and see if its snappin' good and regular... they also sell a spark tester at the parts house, or, full redneck, take a screwdriver, jam it into the coil lead and hold/prop it a good 1/2" or so from a manifold bolt, etc.. and crank it...

I went in a different direction and I think I may be on to something (probably just wishful thinking.)

I measured my voltage coming into my coil and I get 12V. I measured the resistance from my - post on my coil to the - on the battery and I get 296 ohms. The ignition wiring diagram for a 75 EB says that my - coil is supposed to go to the green wire on the Duraspark control module. 296 ohms sounds off, right?

dunno, the ground side of the coil is a transistorized ground within the duraspark module, not a direct ground, dont know if there is a spec on box resistance, checking voltage isn't good enough on the positive side, you can have voltage and not enough current, try checking voltage with it running on the pos. side, this will put a load on the wiring, it should stay at or near vbatt, if it drops there may be an issue, usually the duraspark modules either work or they dont....

dunno, the ground side of the coil is a transistorized ground within the duraspark module, not a direct ground, dont know if there is a spec on box resistance, checking voltage isn't good enough on the positive side, you can have voltage and not enough current, try checking voltage with it running on the pos. side, this will put a load on the wiring, it should stay at or near vbatt, if it drops there may be an issue, usually the duraspark modules either work or they dont....

10/4

I'm chasing this issue on CB.com and the word there is that resistance on the - side of the coil doesn't mean anything. The ground on the coil comes from the module.

I was lazy and didn't check resistance of the + wire from the coil to the switch. I've got to crawl under the dash to check it. I'll try that next.

I still want to believe my new motor is ok. The old motor had a very similar problem that I didn't fix because it was an old 302. I want to believe that the problem stems from the ignition or the vacuum system. Maybe a ground. Switching from a 302 to a 351W based engine, I got a new dizzy but kept the rest of the ignition system. All of the vacuum system stayed too. The vacuum system is just PCV and power brakes.

I'm pretty booked this weekend, but I plan on replacing the PCV valve, its hoses, some ignition wires, and check the ignition's ground.

How old are your plug wires? Did you reuse those from the 302? I had an issue with my 302 since it gets so hot in the small engine bay of my BII. It cooked the plug wires in a year and a half, but they still looked good. When they got hot, the resistance in them was so bad the coil spent half its time arcing from the tower to its terminals, and I had a miss and a top/mid range breakup. New wires = no more problem.

yeh, be sure of the ignition first like was said, i dont care for duraspark anyway, get a msd ready to run or an hei setup, couple hundered bucks at the most...

I'm running new cap, rotor, Ford Racing wires and plugs.

Update:

I pulled the timing cover to see if my chain was indexed properly. Looks ok to me, what do y'all think? The chain has a little slack, but it's new and within tolerance I think.

http://i177.photobucket.com/albums/w229/recoiljunky/2010_0425Cruise20100001.jpg

http://i177.photobucket.com/albums/w229/recoiljunky/2010_0425Cruise20100002.jpg

http://i177.photobucket.com/albums/w229/recoiljunky/2010_0425Cruise20100003.jpg

http://i177.photobucket.com/albums/w229/recoiljunky/2010_0425Cruise20100004.jpg

I guess while I'm in there I might as well replace the cam. Any suggestions? I would want to keep my current valve train. Stock Edelbrock 60259 heads, Comp Cams 1.60 roller rockers, 8.150" push rods. Will I need to replace my lifters? They are new too.

To recap, the motor showed a lean spike at tip in. The HP and torque curves were lower than hoped for and flat. The motor pushes the Bronco real hard, but it breaks up pretty bad if you jump straight into WOT. Adding advance and/or a big squirter makes the break up less noticeable. The vacuum is lower than I expected, 16" at idle, fairly stable. The motor does not smoke. It fires up very quick. I've tried different carbs. They all do the same thing, but of course I'm the same jackass tuning all of them. I've been struggling with this issue for a little over a year now.

i take it you verified your ignition was ok, the chain is ok, pull the cam, maybe it is flat, wouldn't be the first one i've seen and it causes the issues your describing, i can run some cams in the computer and let you know...

i take it you verified your ignition was ok, the chain is ok, pull the cam, maybe it is flat, wouldn't be the first one i've seen and it causes the issues your describing, i can run some cams in the computer and let you know...

Thanks.

I didn't verify the ignition besides checking the voltage at the coil and insuring the wires were routed correctly.

I'm fixin' to pull the cam. Maybe it will be slightly flattened.

What about this one?

http://i177.photobucket.com/albums/w229/recoiljunky/newcam.jpg

I'm running: Edel heads with 2.02 / 1.60 valves, 9.5 to 1 compression, 660 carb, Air Gap intake, .060 overbore, 3.850 stroke, NP 435, 4.56 gears, 36" TSLs...

Should I get a similar profile from another company? I've heard a lot about Comp Cam cams going flat.

i've run that exact cam in a 357" deal with a dual plane and a 650dp, made 360 to the tires, the headers will be "small tube" and the that intake isn't "max-flow" tho... had a slightly lumpy idle in a 357", should be fairly tame in a 393", needs a small convertor..

i've run that exact cam in a 357" deal with a dual plane and a 650dp, made 360 to the tires, the headers will be "small tube" and the that intake isn't "max-flow" tho... had a slightly lumpy idle in a 357", should be fairly tame in a 393", needs a small convertor..

What's a better cam choice? This is far from a daily driver; it's a toy.

I pulled my cam and it looks ok. I measured the lobes with a micrometer. The intake lobes were averaging 1.710" max height and the exhaust were averaging 1.697" max height with some variation. I looked at my cam card and my numbers apparently don't mean anything.

Old cam:

http://i177.photobucket.com/albums/w229/recoiljunky/2010_0425cam0001.jpg

http://i177.photobucket.com/albums/w229/recoiljunky/2010_0425cam0004.jpg

http://i177.photobucket.com/albums/w229/recoiljunky/2010_0425cam0005.jpg

the xe274 would be good all around, looks like it would lose 10-15 lb ft but pick up at 4500 up and pull to 6k where it look to pick up 50 hp or so, neck and neck below that, tried alot of cams and it actually likes a solid flat oval cam the best, but, you probably wouldn't- ha, what does it have for headers again, the combo seems exhaust sensitive as most strokers do, really needs a good larger header...

the xe274 would be good all around, looks like it would lose 10-15 lb ft but pick up at 4500 up and pull to 6k where it look to pick up 50 hp or so, neck and neck below that, tried alot of cams and it actually likes a solid flat oval cam the best, but, you probably wouldn't- ha, what does it have for headers again, the combo seems exhaust sensitive as most strokers do, really needs a good larger header...

I measured the tubes last night; they're just over 1.6" (which makes them small tube since my exhaust valves are 1.6".) Here's what the headers look like:

http://i177.photobucket.com/albums/w229/recoiljunky/DSC01772.jpg

They were custom made for a guy who had a similar motor, although his has Victor Jr. heads, on an EB. They go over the frame, 2 1/2 collectors, Spintech mufflers, out in front of rear tires.

How about the XE284H? http://www.summitracing.com/parts.aspx?sku=CCA-35-250-4 It looks good on the Comp Cams program and I've read good things about it in similar motors. I'm guessing either the 274 or 284 will be a lot more fun than my 262.

How 'bout those lobes? Too hard to tell from the pics if they are flattened any, huh? If they are flattened, it's not much. Do you think the little cam needed too much advance to make power, thereby causing it to run lean? Am I putting too much thought into this? Just try a different cam and see what happens?

Aaak. Get that fram filter off of there! Wix 51515.

Aaak. Get that fram filter off of there! Wix 51515.

I was wondering how long it would take for someone to call me out on that. I usually run a Motorcraft filter but the parts store was out. I do like the grippy on the Fram though. :homer:

I also make up for the Fram by running Rotella. :flipoff2:

Off on the same tangent, looks like I only got about 60 miles out of my oil pan full of Rotella. It's flooded with anti-freeze and broken gasket now. :( It seems like I always break open the motor after changing the oil.

dont think the cam profile had much to do with the jetting issue, that one lobe looks suspect, but it is a pic, going up in duration will shift the power band up gaining hp, trading for torque, the computer shows a little drop in torque with anything besides the 262 deal, but, thats to be expected, the 284 cam will lose more torque and gain hp again, it is up to you, plus it will need a stall convertor...

dont think the cam profile had much to do with the jetting issue, that one lobe looks suspect, but it is a pic, going up in duration will shift the power band up gaining hp, trading for torque, the computer shows a little drop in torque with anything besides the 262 deal, but, thats to be expected, the 284 cam will lose more torque and gain hp again, it is up to you, plus it will need a stall convertor...

I'm running an NP435 4 speed.

I think I'll order a 284 today.

why not look into a custom grind cam. you built a stroker to get the most hp/torque possible and i just dont think you can really achieve this with an off the shelf cam.

Well f me. The new cam came in and the cam card says I need 986-16 springs http://www.summitracing.com/parts/CCA-986-16/

Do you think my Edelbrock springs will be an adequate substitute? Valve spring diameter 1.45", seat preassure 110 - 120 lbs, max valve lift .575" (my cam says gross valve lift of .544.)

As far as coil bind is concerned, youre fine with those springs. Assuming youre not running 1.7 rockers and that spec of .544 is based off 1.6s.

As far as coil bind is concerned, youre fine with those springs. Assuming youre not running 1.7 rockers and that spec of .544 is based off 1.6s.

Thanks, I'm runing 1.6 and the cam card doesn't mention rocker size.

Got the cam swapped and broke in; it seems to be running pretty good. There is some extra noise in the top end though; it seems to be coming from the driver's side valve train. Maybe it will work itself out, maybe I need to adjust the valves again. Maybe bigger cams make more valve train noise. I'm pretty confident that nothing is binding because the motor turns over by hand with the same effort as before.

The carb still needs some adjustment. My vacuum guage gave up the ghost on me, so I need to grab a new one before I finish dialing in the motor and giving the final verdict.

I definitely lost a little torque and gained a good bit of hp.

It's looking more like I didn't adjust my valves right. The motor is starting to make a lot of noise out of the carb, as if an intake valve is opening too soon.

When I adjusted the valves, some of the lifters were mushy and some were firm. They're all new, so I imagine some of the were pumped up with oil and others weren't?

I'm going to pull the driver side valve cover and have another go at adjusting those valves.

Number 5 exhaust valve was WAY out of adjustment. The motor runs like a scaulded ape now. No brake up either. I guess the old cam was going flat.

Thanks for all the advice!

good to hear, just make sure to check the jetting again, there will be more in it with tuning...

good to hear, just make sure to check the jetting again, there will be more in it with tuning...

Yeah, I'm anxious to get it tuned right. Thanks again for all your help; if you're ever down this way holler at me and I'll buy you a beer or 12.