Redline
- Thread starter 273
- Start date
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robert 68 cuda
Well-Known Member
depends on what the car is doing if its street car any wear from 5500-6500 for street and strip 6500 - 8000 pluse .
moper
Well-Known Member
All depends on the expectations and budget. Mopar lower ends are pretty stout with good machining, so it takes some big expectations to force upgrades. If it's a drag car i'll consider having some extra rpm there "just in case" and hte actual rpm will depend on horsepower and expected trap rpm.
It will be a street car that will see some strip time and be run on a few road courses my dyno software say I'll make 426HP @ 6600 and still make 400HP @ 7500. I know that's estimated numbers but the powerband should be similar so I'm thinking of 7500 redline.
The 273 I'm gonna build the bottom end should be good for 8000rpm's fully blueprinted with factory Steel indexed crank, scat rods, custom forged pistons with the oiling crossover tube so the redline will be limited by my valve train. I'm going with solid roller cam and rockers not that i thinks its need for this power level but greedy trying to keep as much bottom end while still having a great top end. Also going with ported out 273 heads gonna run 11/32 valve around stock diameter with beehive springs and titanium retainers and the lightest 1.6 roller rockers which keep my spring pressures needs lower.
scrappydoo
Well-Known Member
I really hope you do something about the 273 exhaust manifolds. They flow like crappy, especially at Tue high rpms you want to run.
robert 68 cuda
Well-Known Member
well then whats the cams power band if solid you geet a little more if it is hydrolic about 200rpm befor your cam runs outyou want your car to stay in its power range.
I'm gonna build my own headers maybe Tri Y's for more bottom end and ground clearance as for the custom solid roller cam it probably gonna be 268ish degrees and .550+ lift. Im waiting to port my heads and get them flow on a bench to see what lift I need and get away with the smallest duration that will accomplish my goals, I'd rather sacrifice top end for a broader power curve.
mike at mrl performance has top quality roller lifters for a great price maybe still on sale
OldmanRick
Well-Known Member
When you finally pull this off, and i'm sure you will, i want to see some good quality video, or should i say audio. Cause nothin' sounds like a short stroke at 7,500+. You've really done a lot of research on this build in the last few months, so i know it's gonna come together. Good luck on this and i can't wait to here it
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.Right now im in the middle of a move and hoping start on the 65 Cuda in a couple of weeks she needs a lot of work already spent like $5000 on the front suspension and want to start the engine build in the fall I'll keep you guys informed with lots of pics. This will be my first complete engine build, I've done a few cam, high rise and header cars, I can't wait to hear her on the back stretch of Mosport road course revving full out.
robert 68 cuda
Well-Known Member
ya 7500 is not going to be a problem iv had my 426 smallblock up to 8000 so you should have no problems just make sure your stuff is good or she will go bang hard but 7500 isnt going to be a problem for you.
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