4BT Power Recipie

4

4bt bowtie

New member
I am looking for any input as to what would be required to get approx. 350 RWHP from a 4BT, either a VE or P-pump. So far I have only come across VE pump engines but info for a P-Pump model would be nice. I Plan on rebuilding the engine from the ground up and having the rotating assembly balanced. I am considering shot peening the connecting rods just to add some extra strength for future plans while I’m in there. I have seen a few people use the PDR diesel camshaft for the 4bt with good results and curious as to how much of an improvement it is over stock. Does anyone know? The engine will have an intercooler. For the VE pump I’m going with the obvious: 3500 rpm governor spring, probably a fuel pin and some meticulous tuning. I am guessing a set of POD injectors would be required for this power level but I may be wrong. I am going to use head studs for good measure and I am thinking of running a compound turbo set up, perhaps an early model H1C with the 9cm2 turbine over an hx40 or something along those lines. The engine is going in a 1990 Chevy S10 and my goal is to have a RELIABLE daily driver that barely smokes when it is all said and done. Any knowledge would be much appreciated.:charger:
 
Good first post!:welcome:

Turbocharger...look for a HE341 off a 03-04 dodge or an HY35 off an 01-02 dodge, both have a 9cm turbine housing and flow enough to support 350hp being too laggy.

Injectors...I would recommend 7x12 sac type tips with modified pintle lift.

Cam...Colt Cams has a 181/210 grind that will drop in and spool that charger nicely.

Pump...A p-pump will get you there the easiest.
 
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Thanks for the quick replies, I posted a similar thread on 4btswaps.com and it took weeks to hear anything and none of the replies were very helpful.:woohoo:
I don't know exactly what the specs are for the POD injectors as far as orifice size, quantity etc., but where would I find the injectors mentioned by LReiff? I am guessing they would be a custom order, or am I wrong? Since the head will be at the machine shop any way for new valve guides, would it be worth the $$$ to have it ported, and or polished, If nothing else at least on the exhaust side to help with turbo spool up?

I checked out the Colt Cams website and could not find an actual 4bt cam offered other than the custom cam made for the SBC rail. I also checked out the Hamilton cam which I like, would I need to upgrade the valve springs since I am not running large amounts of boost or excessively high RPM?

I've read other builds where people used the HY35 turbo and a consistent issue I've seen mentioned is higher EGT's with the HY versus the HX35. Has anyone seen this same problem? If I used the Hamilton 188-220 cam and had the head ported and polished, would this compensate for the larger turbine on the HX35 and limit turbo lag similar to what the HY would have?

I have also heard of a hybrid turbo that uses a stock non-waste gated H1C turbo from an early model dodge then replace the turbine housing with smaller 9cm 2 housing. Supposedly this set up has quicker spool up than the HY35 due to the smaller impeller used in the 4bt turbo. Has anyone heard of this?

Thanks again for the input.
 
yeah the 4btswaps site is packed full of good info, but for the most part the members over there are looking for mileage with these motors not hp, so not a whole lot of high hp knowlege over there from what ive seen. Heck seems like thats all they care about on this site is going fast and big hp numbers! which is great.
 
I've got a 188/220 as well as Zach's springs. Using a HE341 for the turbo. Ported head and inline pump like the one shown above on ebay. I do have another spare pump, brand new untouched I would sell for a few hundred less than the one shown above.

I haven't had a chance to put the engine in the truck yet, but hope to as soon as I get my new garage framed up. Going into a 96 RCLB.
 
4bt bowtie said:
Thanks for the quick replies, I posted a similar thread on 4btswaps.com and it took weeks to hear anything and none of the replies were very helpful.:woohoo:
I don't know exactly what the specs are for the POD injectors as far as orifice size, quantity etc., but where would I find the injectors mentioned by LReiff? I am guessing they would be a custom order, or am I wrong? Since the head will be at the machine shop any way for new valve guides, would it be worth the $$$ to have it ported, and or polished, If nothing else at least on the exhaust side to help with turbo spool up?

I checked out the Colt Cams website and could not find an actual 4bt cam offered other than the custom cam made for the SBC rail. I also checked out the Hamilton cam which I like, would I need to upgrade the valve springs since I am not running large amounts of boost or excessively high RPM?

I've read other builds where people used the HY35 turbo and a consistent issue I've seen mentioned is higher EGT's with the HY versus the HX35. Has anyone seen this same problem? If I used the Hamilton 188-220 cam and had the head ported and polished, would this compensate for the larger turbine on the HX35 and limit turbo lag similar to what the HY would have?

I have also heard of a hybrid turbo that uses a stock non-waste gated H1C turbo from an early model dodge then replace the turbine housing with smaller 9cm 2 housing. Supposedly this set up has quicker spool up than the HY35 due to the smaller impeller used in the 4bt turbo. Has anyone heard of this?

Thanks again for the input.
Click to expand...

If you are not going over 40psi or 3800rpm, you can get the 60lb valve springs. They are usually $110 for 12.
 
Again, thanks for the info. Any other thoughts as to the turbo options or where I might be able to source the injectors from? They sound custom but I could be wrong.

Also out of curiosity, LReiff, what where your considerations for choosing those particular injectors?
 
As long as the spray angle is correct, those nozzles make power and fuel mileage. To determine spray angle, you will need to know piston bowl design, pump type and target injection timing. Depending on pump type, the hole size may also need to be different.
 
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Okay, makes sense. Do you have any reccomendations as to where I might be able to buy those injectors, assuming those are indeed the ones I need?
 
Thanks for the offer on the injectors but I'll pass. What is the general concensus on aftermarket gasket sets? I have seen various companies that offer full gasket sets and full rebuild kits for the 4bt and they are cheaper in price than OE Cummins parts. My suspicion is that they are cheaper in quality as well, am I right?
 
Non intercooled piston, 155° injector. You could use a JD nozzle if you desired to, but I believe a cylindrical sac type injector might not be best for efficiency.
 
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