Aidan

I think im on my last decision and I wanted to get some opinions before i decided against using a 4.0" stroker crank.

Im building a big nitrous based re-sleeved motor. with all the parts you see in my signature (240-250 @ .050 cam, absolute x2 heads)


A 388 all bore and a 427 should make almost identical real wheel horsepower correct?? But the 388 will make it at a little higher rpm and make alot less torque and less area under the curve correct???

With a 300-350 shot torque is almost to much trying to keep it down to get the car to hook and launch.... So a 388 with a ton of spray should ET just as well as a 427 without spending the big $$$$$ on a crankshaft correct??? I dont want to do with the 4.0" crank if rwhp will be close to the same.

niphilli

A 427 will always have the potential to make more power than the 388. The advantage of building a 427 with the same power as a 388 would be driveability and low end torque. It is all going to be centered around the size of the cam you are going to run...ie. you can run a bigger cam with the 427 to get more power or the same size cam to get similar power as the 388 but more power under the curve and better daily driver characteristics.

383ss

iTrader: (14)

Eagle cranks are only about 900 now....

VINCE

iTrader: (1)

Where do you get a 388ci makes the same peak rwhp as a 427ci? Most of the 427ci guys are not running a max effort setup. Most are running small cams for their engines.

Aidan

Ive done a lot of dyno work and seen alot of "De-stroked" engines....

Common example would be a 406 SBC compared to a 377 (400 block with a 350 crank).

The 377 would dyno with a powerband thats shifter much higher in the rpm's (Loves to rev), the 406 would make alot more low/mid range but often actually peaks a little more rwhp. With less cubic inches.

Id say if you took a 388 and swapped to a 427 in identical form, you would probably actually make a few less rwhp PEAK (427 might peak @ 6000, 388 probably around 6500) but a TON more low and mid range torque.

the 427 would ET better by far in a 1/4 mile race but it wouldnt out MPH the 388 car (it might actually mph less), so a BIG nitrous motor might actually run faster with a 388 because you can use more nitrous off the line.... If a car is leaving on a 300 shot the 427 would serve no purpose, as the torque is usually unusable, since a 388/300n20 setup would make 800-900 rwtq off the line...


Anyone follow this theory or no?

8cylinder6speeds

That maybe true however why would you stick a cam that was designed for a 388 into a 427, the 427 will swallow a heck of a lot bigger cam. If you went all out in both motors the 427 would give you better results pending your car could handle all the power.

niphilli

I agree with this completely.

I can say that if you are looking for a high reving motor (ie huge cam) you would probably be better off with the 388 setup. As you said above engines with long strokes do not like to be revved to the moon.

timelord

Why not 427 with a 2 stage N2O set up for launch??

Mike 01WS6

Thats what i was thinkin. Why not give each motor the same chance. And you don't neccessarily have to spray the 300 out of the hole on the 427.

99 Black Bird T/A

iTrader: (4)

Here's my take on this...MTI & ARE warranty their Big Bores with dry sleeves...but they don't warranty Big Bores with dry sleeves that get sprayed.

I don't think it's wise to spray a 300 shot on a dry sleeve Big Bore and expect it to live very long. The sleeves would be getting hit with a massive spikes in cylinder and with .08 to .06 of material holding a liner in place, I think that's asking for problems pretty quick. Likewise, almost all Big Bores use stock cranks and most use stock rods. Spraying off the line & down the 1/4...would probably subject the stock crank and rods to ~800+ flywheel hp and ~1000+ flywheel torque. I don't think a dry sleeved 427 would fair any better. Sounds like a time bomb to me and I like Big Bores.

With that said, I think a stroker is motor to go with to spray the **** out off. Not sure about the Eagle crank as we really don't know it's limits at this point for spraying 300shots but the Lunati rotating assembely in a stock bore LS1 should live quiet a while with good tune. I'd favor a LS1 block for big spray set ups because they don't have the windows that could weaken the structure like an LS6 block would have.

Just my rambling thoughts on this...

niphilli

I will admit that I do not know much about the strengths of re-sleeve, but I do know that no tuner will warranty a motor that is being sprayed. I also know that ARE sprayed the snot out of their sleeved motor....sprayed it all the way to the eights.

10.5 Dave

iTrader: (5)

I will be spraying more than a 300 shot to my ARE 422 solid roller right out of the hole.If it does'nt hook I will do more suspension changes.It will be a LS6 block with dry sleeves.I have no worries whatsoever about it staying together.I will spray it right into the 8's at 3300 lbs.

99 Black Bird T/A

iTrader: (4)

The difference is while ARE uses a dry sleeve it's a custom Darton sleeve not the LA Sleeve Aidan is referring too. I should have been more specific as to which dry sleeve was was refering to as not all dry's are the same design.