|02-15-2019 09:47 AM|
Side pic.... I posted the same one twice by accident above.
|02-14-2019 09:25 PM|
I'd like to see side pics, and some explanation of wtf is going on. I was really hoping this was maroon and wood paneled on some gold mods somehow proportioned just right
|02-12-2019 06:06 PM|
|02-12-2019 05:47 PM|
|02-12-2019 05:19 PM|
|02-12-2019 11:36 AM|
|lowerd96||I've never seen anything like that...period.|
|02-12-2019 10:02 AM|
|Mikel||Interesting. I've never seen a cross-over compound turbo setup before.|
|02-12-2019 09:25 AM|
A couple pics stolen from IG for you fawkers.
|02-11-2019 08:49 PM|
|v30crewcab||marine pistons should be fine, but ditch the 20 over head gasket, unless you decked the block or the head alot. its killing your compression. not sure how much the marine pistons lower it, mainly they have a larger bowl for the wider spray of marine injectors or higher timing. anything over 18-20 degrees of timing is going to kill your bottom end for a stickshift.|
|02-11-2019 08:22 PM|
still don't own a 4x4
Post some goddamn pics, loves me some first gen caravans
|02-11-2019 08:11 PM|
|SLOWPOKE693||I REALLY want to see pictures! This thing sounds kinda cool in a red headed step child kinda way.|
|02-11-2019 06:28 PM|
And I agree with the dedicated cummins and diesel forums, but I applied for accounts on 5 different ones, and they all have administrator supervision on early posts, and all but one of them has yet to approve my initial post and comments I submitted several weeks ago. And I seem to find the most ingenuitive people doing interesting/strange builds on here, so I figured this would be a great community to throw my project into the mix with.
|02-11-2019 03:49 PM|
you should probably be posting this on one of the many different cummins specific forums
youve got compound turbos with an o-ringed arp head, you should have all the power you want, have you tried adjusting your low boost fuel levels?
|02-11-2019 02:50 PM|
I did get my injectors tested. I wasn't expecting them to be great, but overall the pop pressures only varied from 225 to 250, with one exception being injector #5 at 270 bar, which is definitely too high. However, all things considered that isn't too bad for the variation, and again it did idle and run smoothly, never a hint of a miss or anything like that. So while they might not be the best engineered solution, I think for the most part the injectors are doing their job. I would like to get some that fuel more efficiently than the 370 tips, but that is $ that will have to be put aside later...
I am definitely lacking power throughout the powerband. For example, my buddies completely stock '94 p pump truck pulls much harder. I feel that all in I should at least be able to give him a run for his money. No such luck. But yes, I do have very little power down low. Unless I can keep rpm's up on the highway, the gap between 3rd and 4th (granted, my 3.07 gears don't help the gap size) is almost too much to pull up from on anything other than flat or downhill.
I think that my intercooler system is sufficient. I can read an 80 degree Fahrenheit drop in intake temp between having the pump on or off, so I think that is good for efficiency there. But I do agree that my radiator is quite likely too small. The only problem I have is real-estate. I basically have none. I am willing to re-design my front end to accommodate more radiator, but I still think I will have to tig up a custom unit that trades face surface for depth. Something like cutting a big radiator in half, merging the tanks, and having it 4" thick at half the height. Only way I can see it fitting with the tapered nose of the van.Frame rails are a bit tight too.
Once I get rebuild the new internals for my transmission I will try returning the timing back to stock and seeing what that does for me. However, as mentioned earlier, with the transmission and fuel system removed (three tanks, lots of valves and a transfer pump) now would be the time to do engine work if I have to. Though I still can't see affording the ~2k for new pistons and injectors anytime soon.
Also, I was talking with a few local diesel performance shops, and a bit of advice I saw regularly was to remove my heavy weight valve springs in favor of stockers. Because I have the 110# springs, heavy duty pushrods, and hardened tappets, but only a stock cam, I was told that they will eat up the camshaft and heavily/prematurely wear it down. To me, the spinning design of tappets should negate this type of wear, but I have little experience in this area. Is there any truth to this?
|02-09-2019 06:41 PM|
|02-07-2019 12:14 PM|
|Java||No cummins expert here, but if you ahve no power under 1k, I would bet the marine pistons are part to blame. Boats run at 60-100% of redline, they never (well nearly never) run at low engine speeds. Those pistons are probably designed with 80% of redline in mind|
|02-06-2019 01:23 AM|
|klutch||Also I don’t think you are gonna want any smaller of a radiator or intercooler than a first gen Cummins has. I’m no stranger to those rigs and they are just adequate with mild turning up. I also have a thing for minivans (Astro vans mostly) so there is a lot about your project that interests me|
|02-06-2019 01:09 AM|
|klutch||He has a fuel pressure gauge so I don’t think he wants to put money into that end of things if that’s not a problem right now. I’m in a fairly similar situation in some ways. I built my motor sparing no expense really and went marine pistons because the machine shop recommended them. Mine is a ppump in a Ford but I still feel you on some points here. I put it together with marine 370s and it was stinky for sure. Lots of stink and idle haze. I threw ddp injectors that I had in and that improved the stink a lot but still kinda stinky and hazy. This is all relative to 12v as I’m far from new to old diesels. Power is good but not quite where it should be as well as slightly lower boost and slightly higher egts. I have a huge radiator and big superduty intercooler so that probably cancels those problems you are having. The big problem beyond the stink that I have is really low power at low rpm. Power comes on smooth and nice around 1k rpm but has nothing below that. Is your low power across the whole rpm range or down low? I’m suspecting the marine pistons are what I’m not liking but like you i put a lot of time and money into it and dread pulling it all apart again. I’m running stock timing since my lack of power is mostly down low.|
|02-05-2019 08:17 PM|
|||link the pics for us without the instantgrams|
|02-05-2019 08:15 PM|
with the bd fuel pin, 3200 spring, and bigger injectors the stock lift pump can sometimes hit 0 psi at full load, that can starve the injection pump of fuel and decrease its life and performance. the point of the better lift pump is to elimiate any fuel pressure problems that can develope and just to keep your rebuilt injection pump living a long healthy life, your motor is pushing more fuel than stock.
|02-05-2019 07:43 PM|
Thanks for all the advice.
Didn't realize that photos would have such an impact, but that's very helpful info in and of itself.
I also don't want bigger injectors and never have, the 370 modification was unfortunately the only option on hand to get my stock bodies in the 7mm head bores, while maintaining the correct spray angle for the pistons inside. I agree that more fuel is not (hopefully) the answer, as many of the miles are on the highway driving across the country, and extra fuel can only make my trips more expensive.
If new/stock compression pistons are the answer, as I have feared they are, as mentioned above would anyone have suggestions as to which style of stock piston I should aim for? Intercooled or non-intercooled (mushroom vs pyramid) as I haven't found any conclusive information as to which would work best, and without making an informed decision I also cannot seek out the proper injectors.
|02-05-2019 07:32 PM|
You need to ditch the marine pistons, lower compression ratio like your aware of and think about how a marine engine is used versus something used on the road. A marine engine runs at the top half of the rpm range and at pretty much a constant speed, your pretty much doing the exact opposite.
I dont understand why everyone with a cummins thinks they need to put bigger injectors into it, stock turbo trucks are overfueled with stock injectors after the typical pump mods. I know that youve got different chargers on it but it sounds to me like your way overfueled also. Injectors and pistons must be matched, different bowl sizes and shapes need to match the spray pattern of the injectors. Mismatched is gonna have fuel puddled in the cylinder instead of swirled and atomized.
I agree with resetting the pump gear timing to back where it should be. 25* of timing over stock with as much fuel/boost as your saying sounds like a great way to knock some holes in pistons and window a block.
|02-05-2019 07:15 PM|
You need to match the piston and the injector spray angle. It's critical that the fuel hits where the piston is designed to compress it. I don't know if just the tips will work... I know it doesn't for my wife or my GF
So, do your injectors have the right spray angle for the pistons? If not, that's white smoke you will never fix without it.
I'd call Eric at Diesels and pick his brain.
He can help you out.
|02-05-2019 06:59 PM|
The questions in the above post are much more important, but I forgot to mention the blasphemy of a few things. While I did try to keep some things mopar era, it does maybe have a few parts that dont belong. Like the 2010 Chevy Silverado headlights, and the Ford Super Duty mirrors.
And the weird door hinge and hood closure mechanism (keeps it from opening at speed, and acts as a low pressure zone generator over the hood louver I made in an attempt to increase airflow through the radiator(s).
Many apologies if this offends any brand loyalists. But at least this way everyone is included!
|02-05-2019 06:50 PM|
For the photo requests, I made one of those instagram things that are all the rage these days, or something like that. The account name is: theturdwillneverdie
Because the affectionate name of my contraption is "The Turd", and I am so far past committed at this point that there's no way I can ever get rid of it.
To the recent recommendations, thank you very much for your advice, I will be looking into it all some more.
To rockyota: do you think that the high flow lift pump will solve the problems? I mean, I am sure that my setup is fuel limited as far as reaching its full potential is concerned, but I feel as though I am not even hitting stock/slightly modified power levels right now, which I think that the current lift pump should be able to support. If I am not wrong (entirely possible on so many fronts) many 1st gen users seem to just bump timing and max fuel and pull their own weight at a remarkable pace. I struggle with the gap between 3rd and 4th on even mild inclines, which seems to be kinda sad given all the things ive done in an attempt to improve.
Ill retard the timing again as mentioned previously, but maybe tilting the pump first so I don't have to open the case just yet. As you will see in the pictures, there's a fair bit of gear to remove to access anything with more than a parts grabber.
As for injectors, are there any recommendations of types or sizing given my current setup?
And more importantly, this goes out to everyone: if I am looking to regain my fuel economy at nearly all costs (gulp) should I truly consider going to a different compression piston? And if so, albeit at 20 over bore, should I go for stock non i/c piston shape (155 degree/marine spray pattern) or a stock i/c piston with the mushroom? Because if this is something that all of you more experienced tinkerers believe I should do, your answer could result in the need of a different injector, and if I have to do that, there's no way I can afford to do it twice.
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