Need advice on replacement engine: VCM5RC 4 Bolt Roller Cam

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CHEVYS4ME

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What Throttle Body are you going to use? The stock 42mm won't give you enough flow when getting up over ~4800RPM, the 7.4L TB won't idle very well plus, it's too big (50mm) for your 3704 manifold. You can get a bored 46mm (650 CFM) with all the "Ultimate Mods" from SPR and bore the manifold out to 48mm for better flow.
https://www.ebay.com/itm/46mm-PORTE...837306?hash=item3d963196ba:g:mpwAAOSw2xRYWVJj

You'll want an AFPR and probably an 18 LB or higher spring. You can get the spring ordered with the TB. I don't know if he offers an AFPR but you can get it here. HTH
http://www.rvmorsemachine.com/product.htm
I'm using stock unit, new throttle shaft bushings, Dremeled lip down, thinned throttle shaft, stainless 1/4" injector spacer, 18 lb spring, new injectors, vortec fuel pump, adjustable fpr & fuel pressure gauge.

I should have enough cfm, and be able to adjust fuel pressure as needed.
 
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PlayingWithTBI

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I should have enough cfm, and be able to adjust fuel pressure as needed.
Keep in mind, if you take your 18LB spring up over 20PSI it'll become spring bound and won't work very well. I tried a 28LB spring (from a 94 - 95 7.4L), set @ 28PSI for a while but couldn't get it to idle very well. My injector Duty Cycle was ~80% WOT @ 5200RPM with it. Now, with the 18LB spring set @ 20PSI my duty cycle is ~92% but I was able to get it to idle well in Open Loop. I also tried 80LB/HR injectors from an earlier model 7.4L and when I ran the automatic VE learn in the EBL, it actually shut off the injectors trying to get the AFR right at idle, ha ha.
 

CHEVYS4ME

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I just purchased a custom "Motorvation" chip from Summit Racing. It is the same company Edelbrock uses for the chip they give you free with head, cam, and intake purchase. I purchased the Summit Racing heads so I had to purchase it. They will contact me with my setup, and ship it out in about a week.

I contacted Edelbrock, and Summit and both said I would need some type of chip to not run lean. Even though parts have C.A.R.B. cert, it changes it enough to need to be re-tuned.
 

L31MaxExpress

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What Throttle Body are you going to use? The stock 42mm won't give you enough flow when getting up over ~4800RPM, the 7.4L TB won't idle very well plus, it's too big (50mm) for your 3704 manifold. You can get a bored 46mm (650 CFM) with all the "Ultimate Mods" from SPR and bore the manifold out to 48mm for better flow.
https://www.ebay.com/itm/46mm-PORTE...837306?hash=item3d963196ba:g:mpwAAOSw2xRYWVJj

You'll want an AFPR and probably an 18 LB or higher spring. You can get the spring ordered with the TB. I don't know if he offers an AFPR but you can get it here. HTH
http://www.rvmorsemachine.com/product.htm

I bored several manifolds to 50mm and ran 2" big block or marine TBI units. Never had the idle issues you mention. They idled perfectly. Even with both a high rise victor jr single plane and a Weiand 177 it still idled perfectly.

I was also twisting one to 5,500 rpm on a regular basis with a stock bore TBI. The MAP would drop a little and the power would flatten up top but it still made great power (~330 hp crank) in the 5,000-5,500 rpm range.
 

CHEVYS4ME

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You DO know that the intake manifold is not CARB legal right?

I found out that the Edelbrock TBI manifold is not C.A.R.B. certified, but it doesn't need to be. It is listed as a "replacement" part, which is perfectly legal in CA. It states in the manual to keep documentation and list of vehicles it covers. My truck is clearly listed as it fitting.

Finally got all parts together, and am starting the engine assembly now.

Looks like my old engines crank front thrust bearing went. About 3/8" movement in crank back and forth. This was a GM crate engine with 45k on it. I know po, and truck wasn't abused. I think it must have been a error in machining, assembly, debris, or something else causing bearing to wear out prematurely.
 

CHEVYS4ME

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I also had a custom chip burned by Motorvation. Same company Jegs uses to burn chips for their customers. I will let everyone know how well it works.
 

PlayingWithTBI

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I found out that the Edelbrock TBI manifold is not C.A.R.B. certified, but it doesn't need to be. It is listed as a "replacement" part, which is perfectly legal in CA. It states in the manual to keep documentation and list of vehicles it covers. My truck is clearly listed as it fitting.

Well then, why does Summit Racing have this disclaimer on their website? I'm guessing it's not a direct replacement because it's taller. I have the same manifold and figured if I had to, I'd swap my OE one in every 2 years.

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Schurkey

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Looks like my old engines crank front thrust bearing went. About 3/8" movement in crank back and forth. This was a GM crate engine with 45k on it. I know po, and truck wasn't abused. I think it must have been a error in machining, assembly, debris, or something else causing bearing to wear out prematurely.
Define "front" thrust bearing. Do you mean the thrust lip of the bearing that faces the front of the engine? Or do you mean the thrust cheek on the crank that faces the front of the engine?

If the wear is from the crank pushing forward, and you have an automatic trans, don't install the next engine without verifying the transmission cooler tubes, and the cooler itself for restriction. Possibly even a pressure-test with the engine running. Excess cooler pressure causes thrust bearing wear via pushing the torque converter forward.

If this is a manual trans, you might want to verify the pressure plate isn't excessively stiff.

If the wear is from the crank being forced rearward...I got no answers.
 
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