408 stroker buildup

[gm442]

i'm building 408 stoker motor using a 1999 5.9 motor.
using a scat cast crank rotating assembly with flat top forged pistons with valve reliefs . should be around 12 to 1 comp .
I have set of mild ported eq heads 2.02 intake valve heads hughes valves ,dual springs, roller rockers.
motor is internal balanced and hughes main girdle setup.
using a hughes HER5864aln-14 roller cam.
will the scat crank hold up to over 500 hp? 550 hp?
will I have enough valve clearance ?
using a 904 with low gear set ,what rear gear, stall should I use?
I have a new mopar performance 175k convertor should I use it ?
the car is a 73 dart swinger with 9 inch ford rear and caltrac setup with mono springs ,26 inch tire.
any advice on the whole setup?
like to run 11.50 et

 

[flyfish]

i'm building 408 stoker motor using a 1999 5.9 motor.
using a scat cast crank rotating assembly with flat top forged pistons with valve reliefs . should be around 12 to 1 comp .
I have set of mild ported eq heads 2.02 intake valve heads hughes valves ,dual springs, roller rockers.
motor is internal balanced and hughes main girdle setup.
using a hughes HER5864aln-14 roller cam.
will the scat crank hold up to over 500 hp? 550 hp? If you have to ask the question, you should have gone forged...but it should hold up.
will I have enough valve clearance ? You have to measure to be sure...but probably.
using a 904 with low gear set ,what rear gear, stall should I use? 4.10 gear, 4500-5000 stall, 8" converter.
I have a new mopar performance 175k convertor should I use it ? If you like handicapping your car and making it not live up to its potential, yes.
the car is a 73 dart swinger with 9 inch ford rear and caltrac setup with mono springs ,26 inch tire.
any advice on the whole setup? Good 90/10 shock up front, get a taller tire out back (28" would be better). You should hit your 11.50 goal.
like to run 11.50 et

Reply is in bold within the text.

 

[75Sport]

I would not use a cast crank in a 12.5 engine. IMO

 

[moper]

Crank will work fine. You don't say what valve covers you have - stockers probably won't clear but any LA cover will fit too so buy a set of taller ones.

 

[gm442]

changing cam to a hughes her3642aln-10 little less duration and lift.

 

[jimjimjimmy]

the cast scat steel crank is a good piece and will easily do the task like mopar said

 

[mshred]

Reply is in bold within the text.

This

I would not use a cast crank in a 12.5 engine. IMO

and this


This is just my opinion though...Good luck, hopefully it runs strong!

 

[gm442]

Why did scat make a cast crank assembly with high compression pistons ?
I called scat and asked them ,they said this assembly will handle 600 hp and not to go over 7000 rpm. Higher rpms and bad install and bad machining breaks there cranks. Other people have used them with no problems for many miles of racing.

 

[mshred]

Why did scat make a cast crank assembly with high compression pistons ?
I called scat and asked them ,they said this assembly will handle 600 hp and not to go over 7000 rpm. Higher rpms and bad install and bad machining breaks there cranks. Other people have used them with no problems for many miles of racing.

you ask if you should use the crank, then you say scat said you will be fine...so Im not even sure why you asked.

good luck!

 

[gm442]

I asked scat after this posting, just to see what they say.

 

[mshred]

I asked scat after this posting, just to see what they say.

I don't think anyone is saying it can't be done, because it has and can...But I don't think personally it can be done for LONG so to speak

Everything with these cars is a snowball effect...your going to want to go faster then 11.50 (which btw with that compression and a decent cam should be cake) and when you do, the cast crank might be the weak point...But hey, you got it already so try it out and see what it does! Thats what I would do too

As I said, good luck with it!

 

[gm442]

Thanks, i have a really good machine shop so i know it will be balanced and setup right.

 

[gm442]

11.50 will be my limit, i don't what to put a roll bar in the car.

 

[mshred]

11.50 will be my limit, i don't what to put a roll bar in the car.

LOL thats what I said

 

[Abodybomber]

11.50 ballpark, myself.(hate roll bars..). FWIW,seen a few 250 N20 hits,on the Scat cast cranks@6600-6800. As long as your machinist cares,your on the money.

 

[273]

Aren't these cast Steel which is a lot stronger than cast iron cranks?? And from what I've read are close the the strength of factory forged.

 

[txstang84]

...As long as your machinist cares,your on the money.

This

 

[Abodybomber]

Aren't these cast Steel which is a lot stronger than cast iron cranks?? And from what I've read are close the the strength of factory forged.

Yes.In between factory cast iron & factory forged. Plus 30-40 years less cycle time.

 

[gm442]

I'm using a set of chrome direct connection valve covers ,will they clear roller rockers ?

 

[hemidak]

I put the same set up together with a 590 Mopar cam and ran a 10:80s with Cal Tracs complete set up. Yes I had to do a roll bar. I didn't think the 904 would stand up so I went with the 727. I am to old to change transmissions every few months. the 904 should be worth a few tenths

 

[gm442]

how much lift and spring pressure can stock magnum rockers take ?