If I have a .570 lift cam with 1.5 rockers and want to run 1.6 rockers that would bring my lift up to .608. Right?

Ok now say I need to know if my comp cams 977 valve springs will be free from bind with a 1.85 installed height. How can I figure that?

Comp 977's: dual spring
O.D: 1.46
I.D: .700
seat pressure: 155 @ 1.850
open pressure: 419 @ 1.250
coil bind: 1.195
spring rate: 441


I keep thinking that cam lift increases by rocker ratio at the valve so a .570 lift cam pushes the valve .855 :confused: No no, the cam lifts .38 and then the "lift" is cam * rocker ratio, I think.


So when I subtract coil bind (1.195) from installed height (1.850) I get .655

Is this enough leeway for a .608 valve lift?

I don't fucking know. Would someone who knows cams and valve train please explain this. :eek:




SBC Quick engine specs:
4.040x3.75 4 bolt 2pc. (Scat forged everything) 385ci
Flat top pistons (Probe SRS)

Dart 230cc Iron Eagles (old style) (Flow 280cfm@.600 lift)
Solid roller Comp cam kit #K12-771-8 (just ordered, 2 week lead time)
850 Holley

1.850
- 1.250
.600 lift

.655 total lift before coil bind. MFG would like to ensure .060 MINIMUM clearance between the retainer and the guide including the valve stem seal to ensure appropriate clearance.

so.... disassemble a head. take a checking spring, run it down to .608 lift, and see how much clearance you have. if you have .035 clearance for valve bounce, and .065 clearance for retainer/seal/ guide setup with a checking spring, then the bigger cam will fit.

BUT!
make sure your intake valve does not hit the piston by doing some checking between 20* btdc and 40*ATDC to ensure that your pistons have enough valve notching done. start by assembling the head on the engine with a checking spring and an old head gasket, checking the depth of plunge on the intake valve at every 4* between 20BTDC and 40* ATDC to ensure you have at least .085" clearance between the piston and valve. if not, have the valves notched appropriately.

edit: If its a solid roller, I would want at least 200 lbs on the seat (*would really like 250lbs), and 500 or more over the nose to get it to rev past 4500, otherwise, i would be nervous as hell. 3/8 pushrods, with a minimum .100 wall would really help too. as would titanium retainers, 10* locks. I would also like my installed height to be at least 1.900 with a 1.550 diameter spring as well.

I already ordered the kit. Why would they only put 155# springs in? Maybe cause it's not a .650 lift? Check it out for me if you would. http://store.summitracing.com/partdetail.asp?part=cca-k12-771-8

1.850
- 1.250
.600 lift

.655 total lift before coil bind. MFG would like to ensure .060 MINIMUM clearance between the retainer and the guide including the valve stem seal to ensure appropriate clearance.

so.... disassemble a head. take a checking spring, run it down to .608 lift, and see how much clearance you have. if you have .035 clearance for valve bounce, and .065 clearance for retainer/seal/ guide setup with a checking spring, then the bigger cam will fit.

BUT!
make sure your intake valve does not hit the piston by doing some checking between 20* btdc and 40*ATDC to ensure that your pistons have enough valve notching done. start by assembling the head on the engine with a checking spring and an old head gasket, checking the depth of plunge on the intake valve at every 4* between 20BTDC and 40* ATDC to ensure you have at least .085" clearance between the piston and valve. if not, have the valves notched appropriately.

edit: If its a solid roller, I would want at least 200 lbs on the seat (*would really like 250lbs), and 500 or more over the nose to get it to rev past 4500, otherwise, i would be nervous as hell. 3/8 pushrods, with a minimum .100 wall would really help too. as would titanium retainers, 10* locks. I would also like my installed height to be at least 1.900 with a 1.550 diameter spring as well.


dammit, you ARE a freakin' android, aren't you??

The springs included with the heads will control a solid lifter (edit: Flat tappet )cam, albeit a small one.


no, I aint an android. Im just a guy.:flipoff2:

1.850

BUT!
make sure your intake valve does not hit the piston by doing some checking between 20* btdc and 40*ATDC to ensure that your pistons have enough valve notching done. start by assembling the head on the engine with a checking spring and an old head gasket, checking the depth of plunge on the intake valve at every 4* between 20BTDC and 40* ATDC to ensure you have at least .085" clearance between the piston and valve. if not, have the valves notched appropriately.

edit: If its a solid roller, I would want at least 200 lbs on the seat (*would really like 250lbs), and 500 or more over the nose to get it to rev past 4500, otherwise, i would be nervous as hell. 3/8 pushrods, with a minimum .100 wall would really help too. as would titanium retainers, 10* locks. I would also like my installed height to be at least 1.900 with a 1.550 diameter spring as well.

To check p to v check the exhaust around 10* before and intake around 10* after. you have to find the tightest spot so between 8 and 15 I usually keep checking untill I find the tightest and generally pay little attention to the degree wheel as I'm actually checking. just start somewhere before where you know its tightest and keep checking a degree at a time untill you find it. If you go past 20* on the int. or 0* on the exh. you have missed or your tdc is wrong.

If you dont have a degree wheel you can use clay. This works well for someone who is inexperienced. just bolt head on with gasket set everything at zero lash and turn over twice.

I agree with the 3/8 pushrods but if you cant make it fit or don't want to buy new guide plates it won't be the end of the world. just run a good one.

I would also like to see a little more spring pressure than the springs that came in the kit. I am not sure what springs came with the head but they may be a better option than the kit spring. That being said most people(me included) tend to run alot more spring pressure than what is really needed with solid roller because it cost very little if no power and does not hurt anything. I believe that is one of there street roller grinds not a race grind so there recommendation is most likely in the ball park.

Brad

Well I got the kit today. I don't understand why they would put such borderline springs with this kit. I have .576 lift with the 1.52 ProMag rockers. We literally can't go anymore lift or shim for more spring pressure. I would like 180-200#'s on the seat. The 977 springs (I think) are rated at 155seat and 420open. So I guess I'll just go with the "Street Friendly" set up they're giving me and maybe later in the race season buy some big dog springs and run my 1.6 Harland Sharps and see what she does.
http://i139.photobucket.com/albums/q282/destro937/090205_190508.jpg



I think my 850 Holley and ported Dart 230cc heads are gonna eat up the big lift at high rpm and the 4.56 rear is gonna give it at about 6900rpm through the traps. O geez, I hope I don't blow this one up and end up with a $5000 table again.
http://i139.photobucket.com/albums/q282/destro937/IMG_0461.jpg
http://i139.photobucket.com/albums/q282/destro937/090116_213815.jpg

oops! oh well,everyone eats at least one i-beam rod! wish i had pics of my 292 that 'let-er-go' high up in the 9000's.

I wonder if the kit comes with lighter springs then a normal solid roller because the cam is ground on a hollow cast core instead of the normal solid roller billet.

I wonder if the kit comes with lighter springs then a normal solid roller because the cam is ground on a hollow cast core instead of the normal solid roller billet.

you want the spring pressure, or it will not rev. to go past 6000 rpm, you need 250 lbs of SEAT pressure on a solid roller.

if you have a cast core, you might have to get a billet core, as they are stronger, and last longer, dont get eaten by springs or by roller wheels.

you want the spring pressure, or it will not rev. to go past 6000 rpm, you need 250 lbs of SEAT pressure on a solid roller.

if you have a cast core, you might have to get a billet core, as they are stronger, and last longer, dont get eaten by springs or by roller wheels.


I understand why you want the spring pressure but i have a cam from the same series and they are cast(found this out when i wanted the cam cut on a small base circle) and i know the recommended open pressure on my cam is 440lbs. My heads came set up for a solid roller and their open pressure is about 700lbs.

my motor
http://photos-f.ak.fbcdn.net/photos-ak-snc1/v2252/243/9/885775356/n885775356_5788805_5045.jpg

So what about the cast cam? Is everything in the kit shit except for the lifters and the timing chain?

you can never tell about every component in a kit.

kits are built out of cheap parts to keep the parts cheap.

I would order application specific parts to ensure the application is survived.
(if youre building a race engine, use parts that are designed with racing in mind, not a high dollar zoot fest that doesnt give you any quality)

I dont know if a cast core solid roller cam is a bad thing because i could literally find no one that had actually heard of them including the company i bought my ignition from.

I know diesel motors that run cast core cams so i know they can hold up to the spring pressure and i dont plan on spinning my motor that fast so i decided to stick with it. I didnt buy the kit i just really liked the grinds theoretical torque curve.

What is the application? I hesitiate to bring it up but those lifters likely have no provision for oiling the rollers and depend solely on splash lube from the cam. That is the apparent main reason people say solid rollers are not street friendly. You can't idle them at low speed for long periods. I know the local chevy guru stands by crowler lifters for street applications. I have the comp lifters as well and just plan on running my idle fairly high as per advice of my friend that runs them in one of his street/strip big blocks motors.

I dont know if a cast core solid roller cam is a bad thing because i could literally find no one that had actually heard of them including the company i bought my ignition from.

I know diesel motors that run cast core cams so i know they can hold up to the spring pressure and i dont plan on spinning my motor that fast so i decided to stick with it. I didnt buy the kit i just really liked the grinds theoretical torque curve.

What is the application? I hesitiate to bring it up but those lifters likely have no provision for oiling the rollers and depend solely on splash lube from the cam. That is the apparent main reason people say solid rollers are not street friendly. You can't idle them at low speed for long periods. I know the local chevy guru stands by crowler lifters for street applications. I have the comp lifters as well and just plan on running my idle fairly high as per advice of my friend that runs them in one of his street/strip big blocks motors.

first.. a diesel doesnt get above 3500, for the most part... how high do you want to spin this?

so far, Red Zone lifters are showing the best wear, crower are second.... comp lifters are ok, IF you get the RIGHT ones.

first.. a diesel doesnt get above 3500, for the most part... how high do you want to spin this?

so far, Red Zone lifters are showing the best wear, crower are second.... comp lifters are ok, IF you get the RIGHT ones.

I have seen a diesel spin a lot faster then that. But it had a stuck injector pinning the rack wide open as it ran away.
But seriously i only bought it up in reference to the spring pressures on the cam. My motor should make peak power at 6000rpm but was built with the intention of chugging along all day at 4000. Will the cam fail? I have no idea. Like i said i tried talking to a few different builders about it but they all just found it odd that such a thing existed. No one suggested it was doomed to fail.

I assume when you refer to the "right" ones you mean the new endure-x lifters comp has out. At over 450 a set they aren't going to be the ones included in the kit for 800 I wouldn't think. The Super Roller lifters come with the kit i am pretty sure. I am actually more concerned with my lifters then with my cam. This whole thread has me thinking about a cam swap again but with Crower's or Isky's lifters thrown in that would run at least another grand i just dont have right now.

I don't understand why they would put such borderline springs with this kit.

Have you gone to the comp cams (http://www.compcams.com/Technical/CurrentCatalog/Default.asp) site and checked what springs they recommend with that cam?

Alex.

but they all just found it odd that such a thing existed.
sounds like they didnt want to insult your choice of parts, but didnt want to do the work for free for you, either. Someone will be nice to you because they know you wont step up and buy the parts you need, as is evidenced by the existing choices made.

I assume when you refer to the "right" ones you mean the new endure-x lifters comp has out. At over 450 a set they aren't going to be the ones included in the kit for 800 I wouldn't think. The Super Roller lifters come with the kit i am pretty sure. I am actually more concerned with my lifters then with my cam. This whole thread has me thinking about a cam swap again but with Crower's or Isky's lifters thrown in that would run at least another grand i just dont have right now.

The endure-x roller lifters are said to be reasonably decent lifters. most people dont understand the issue with low speed engine oiling when using a roller cam, and install oil restrictors in the block, which quickly starves the top end for oil. when idling, the lifters are jacking the oil around in the lifter galley, and there is little pressure at the front of the block. you might be interested to see the oil pressure at both ends of the galley, and see how much difference there is, just by installing a large roller cam. the cam lifts the lobe, the lobe slows or stops the flow of oil in the galley as it moves through its action, and the galley loses pressure on the opposite side of the lifter..

thats one reason large roller cams on the street do not live long. you cannot let them idle.

so far, Red Zone lifters are showing the best wear, crower are second.... comp lifters are ok, IF you get the RIGHT ones.


Youre correct about the Isky lifters.

From my own experience in my 540 cid BBC.
After 3 seasons of drag racing, going through the traps at 7800 RPM, the Isky Red Zone lifters show nearly zero wear.

IMO Isky cams and lifters are the real deal.

sounds like they didnt want to insult your choice of parts, but didnt want to do the work for free for you, either. Someone will be nice to you because they know you wont step up and buy the parts you need, as is evidenced by the existing choices made.



.

Had nothing with not wanting to insult me and certainly has nothing to do with me being too stingy too buy the right parts. You are too funny.

I had reservations about the cam being cast when i found out after ordering it ground on a small base circle only to find the smallest base circle they could grind it too was 1" because it was cast. In talking to the rep at Competition Products and Comp Cams i was convinced the cam wasn't going to be an issue at the rpms i am turning. I was more then willing to spend the money for a billet cam, but there are no factory grinds anywhere near as mild as what you find in the that series of comp cams with mine being the mildest and i was told it would be a waste of money get it ground custom by the aforementioned.
When i ordered my ignition from ICE i had told them my engine specs and they said i would need a brass or composite distributor gear because of the solid roller cam. I told them my solid roller was cast and they said they had never heard of that. As i recall they found it quite odd.

The lifters i bought ignorant to the issue if i had know better at the time i would have gone with the crowlers. I talked about it at length with a knowledgeable builder and decided to try them for a season with the idle set high and of course not idling the motor much. He seems convinced its workable. And he knows if he told me i need to buy a different cam and lifters i would. Everytime i mention getting a different cam i get the same reaction, "its going in what? your 4runner? that cam will be fine, its going to be crisp, that's what you want". I will pull the intake and have a look at the end of the winter next year as this thing isn't likely to be rolling until late fall.

I built my motor as a compromise between low end torque and horse power. Its not a drag motor and was never intended to be.

Youre correct about the Isky lifters.

From my own experience in my 540 cid BBC.
After 3 seasons of drag racing, going through the traps at 7800 RPM, the Isky Red Zone lifters show nearly zero wear.

IMO Isky cams and lifters are the real deal.

Out of curiosity, how often do you change your valve springs? Is it a case of checking them regularly for proper tension or changing them on a schedule or is it not an issue at all?

I did get the endure X lifters, 818's. Seems as tho comp has put some time and effort into making these things live on the street. I am also not going to run a windage tray or crank scraper on the pan for a good splash. O and as to the cast cam, do I still need to run a bronze gear on my dist?

I did get the endure X lifters, 818's. Seems as tho comp has put some time and effort into making these things live on the street. I am also not going to run a windage tray or crank scraper on the pan for a good splash. O and as to the cast cam, do I still need to run a bronze gear on my dist?

818's are Super Rollers.
No you dont need the bronze gear.

http://store.summitracing.com/egnsearch.asp?N=700+4294925232+4294924497+42948929 01+400114+4294892890+4294908216+115+4294840140

Yup i talked to(emailed) comp and they responded saying all their solid roller lifters produced for the last two years are endure-x including the super rollers.

Out of curiosity, how often do you change your valve springs? Is it a case of checking them regularly for proper tension or changing them on a schedule or is it not an issue at all?

On a high RPM race engine I recommend replacing them every season.
High lift and duration solid roller cams are brutal on valve springs.

As Grumpy stated earlier high spring pressure is essential for high RPM capability and valve train stability.

I understand why you want the spring pressure but i have a cam from the same series and they are cast(found this out when i wanted the cam cut on a small base circle) and i know the recommended open pressure on my cam is 440lbs. My heads came set up for a solid roller and their open pressure is about 700lbs.

my motor
http://photos-f.ak.fbcdn.net/photos-ak-snc1/v2252/243/9/885775356/n885775356_5788805_5045.jpg

Choly girdles batman!

:eek::eek:

I saw those in the summit catalog and couldnt figger where they would even go. friggin amazin!!

I thought I read on here someone called and talked to comp about the 818's. They said that all their newer lifters are the Endure X with the precision sized and tool steel needle bearings and squirter. Was this you Rusty? Cause your post is edited.