4BT stroker build

C

clarkoh

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Jan 7, 2014
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I have mentioned my build on here before, I think. The mind is a terrible thing...
Anyway, the rods are on the way, crank is in hand, 0.750 thick slab of ductile iron ready to be planed....I am ready to get pistons, bore a block & start fitting the thing together.

It will be 4.5 liter, 3.9 block, +.250 rod, ported 8V head, custom intake and exhaust, P pump and twin turbos. Primarily for cruising and drags. 5 speed, etc.

QUESTIONS:

1) What would be a good choice for a cam?

2) I plan to use a marine style bowl Mahle piston with coatings. Based on the cam selection, where would be a good place to start with valve reliefs? Since the extra stroke will bump the compression about 2 points, a little extra depth in the reliefs will not be an issue.

3) What would be the ultimate comp ratio to work with the twins and stick shift?

4)I have an hx55 that is being used to mock up the plumbing and an HX30W from the bread truck for the top. Can either of these be used for my twins?

Going in a '48 pilothouse with a 2000 model Ram chassis, running gear and Dana 80. 3.54 rear gear and 18 inch wheels.

Thanks
 
What kind of power are you going for? How many cc's will the PPump move for fuel? How big of injectors will you have? What kind of rpm will it spin? Do you want it to spool fast or is spool time not important?
 
1) Refrain due to bias
2)0 Reliefs, keep that compression up
3) I like 18-18.5" for my daily drivers especially when you are working with limited displacement.
4) There are better choices out there not factoring cost, but those should perform fairly well in a twin setup for your application.


Post up some pics please. Sounds like a really cool build!
 
DDually said:
What kind of power are you going for? How many cc's will the PPump move for fuel? How big of injectors will you have? What kind of rpm will it spin? Do you want it to spool fast or is spool time not important?
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I would like to be able to run high 10 second e.t.s. Using the old 48 body and the shortened 2000 chassis, I expect the truck to be 4000lbs. Maybe less. 10's should be a reasonable expectation.
That brings up some more questions.
Who can I get to do my pump and a set of injectors to match? I pretty much expect to use a 5000 governor spring. It will not be a daily driver, so if its a little bit radical, that's OK. We plan on using the HX30 with a 35 compressor wheel. Waste gate the small charger so it does explode!

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By the way. If I maintain stock clearances piston to head, etc. The increased stroke brings the comp ratio to 19.9. I am pretty sure giving the valves some relief will be OK.

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You shooting a wee bit low on the air side bud. 10's? You can't slap some **** together before the sun goes down and run 10's. Eh I'll let others take it from here. Oh BTW it would be in your best interest to listen to Texas, he knows a couple things haha
 
Got a couple powerglides from my old drag car. The 8" converters would probably be a bad choice, though. They flashed to about 5800 behind a 440! But the trans brakes hit like gang busters!

Hmm! Good point. Maybe a Lenco or a Liberty? Would be a cool choice.

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BramanteCummins said:
Hey I have a set of Mahle big bowls. Used but great shape, .020" oversized
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How big are the bowls? One block I have probably won't clean up at +.020. The other might. How much? 4 or 6 of them? Stock compression height & how far down is the top ring land? Need at least 1/2" so the top ring stays in the block, below the deck plate and extra head gasket.

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DDually said:
You shooting a wee bit low on the air side bud. 10's? You can't slap some **** together before the sun goes down and run 10's. Eh I'll let others take it from here. Oh BTW it would be in your best interest to listen to Texas, he knows a couple things haha
Click to expand...

You actually could if it's <4000lbs. He's not going to need 1000hp.

jlbayes said:
you plan on rowing an nv4500 into the 10's?
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Same as above. Make up for shift lag with awesome top end.
 
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jlbayes said:
you plan on rowing an nv4500 into the 10's?
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Not being involved with diesel drag racing, but looking forward to getting involved, what transmissions are being used successfully for heav(ier) trucks making 5-600 Horsepower?

Is spending $5000+ to upgrade a 47RH the way to go? Can these be launched with a trans brake?

Can an NV4500 be setup for rapid gear changes?
 
Look through ahales build thread. He gave the stick a good chance many times, he now is running a built auto with a manual valvebody
 
The only stick I raced was a Ford top loader in a car with a partner. Got my own car and never looked back. C6, torqueflite and glide. Saved the best for last. In terms of affordable with good results and killer consistent RTs. Glide gets it done with some reasonably priced upgrades.

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ymuza2yr.jpg

Left motor mount. Offsets the engine one bore spacing from where the 6bt would mount. Clears starter and PS pump. Used a urethane suspension bushing, which is 1-1/2" narrower than factory dodge. With slotted holes in trans xmember, this allows tweaking the engine position front to rear in Ram chassis. Will use some aluminum hockey pucks to lock in position once the body is located.

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dajana3a.jpg

Right side mount. More complicated to offset engine location and clear turbo oil return. Same deal with 1-1/2" space to move engine front to rear. The plate part which bolts to the block is 12" tall. The lower turbo bolts to the top of it for support.

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