418" LS3 stroker with 237 Cathedrals heads to dyno
08-01-2015, 01:39 PM
#1
418" LS3 stroker with 237 Cathedrals heads to dyno What will it make?
Do the catherdral port heads keep up with the rectangular ports on these size engines in modest efforts keeping the mannerisms worthy for street use?
I haven't frequented the forums a whole lot but see alot of threads debating this. I chose the cathedrals for this build.
- 418 (LS3 block, 4.070" bore)
- 4" Compstar crank, Compstar H-beams, Wiseco -3cc pistons
- 237cc Cathedral port heads (Trick Flow porter castings worked by Chris Frank)
- BTR .660 spring kit
- small solid street roller (250/254 .650/.620 112lsa)
- 11.75 comp (pump fuel)
- Edelbrock SV 4150 top
- 1 3/4" headers stepped to 1 7/8"
- 850 Q series QFT carb
- KUP front dizzy kit
- wet sump
BTW, I like carbs and those distributor thingys too.
Do the catherdral port heads keep up with the rectangular ports on these size engines in modest efforts keeping the mannerisms worthy for street use?
I haven't frequented the forums a whole lot but see alot of threads debating this. I chose the cathedrals for this build.
- 418 (LS3 block, 4.070" bore)
- 4" Compstar crank, Compstar H-beams, Wiseco -3cc pistons
- 237cc Cathedral port heads (Trick Flow porter castings worked by Chris Frank)
- BTR .660 spring kit
- small solid street roller (250/254 .650/.620 112lsa)
- 11.75 comp (pump fuel)
- Edelbrock SV 4150 top
- 1 3/4" headers stepped to 1 7/8"
- 850 Q series QFT carb
- KUP front dizzy kit
- wet sump
BTW, I like carbs and those distributor thingys too.
08-01-2015, 04:20 PM
#3
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I would call that a "Medium Sized Solid Roller for the Street" LOL!
Should run great subbing in for results.
I predict 720+ FWHP @ 7200+RPM!
FWIW 1 7/8"-2" Step probably worth at least another 8-12 FWHP.
When do you run it?
Should run great subbing in for results.
I predict 720+ FWHP @ 7200+RPM!
FWIW 1 7/8"-2" Step probably worth at least another 8-12 FWHP.
When do you run it?
Last edited by NAVYBLUE210; 08-01-2015 at 06:06 PM.
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08-02-2015, 10:38 AM
#9
TECH Veteran
What kind of car it's going in ?
08-02-2015, 01:48 PM
#11
I gave up a little on the camshaft to be able to enjoy a little nitrous.
I would like to see the car in 'sleeper' trim go some 9.20's on a baby shot. It weighs 3200# with an iron block Gen 1 and a TH400 and has gone 10.90's on 540fwhp with a 3200 converter and 3.70's. It will be getting a TH2004R for o/d and lock up with the LS swap and a fairly loose converter (3600-3800) for performance benefits. But locked up, it should be nice for highway cruising if I can minimize any low end surging.
I am using a Digital MSD box to be able to crutch the timing curve where needed.
08-03-2015, 08:06 PM
#16
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Around 720 to 700hp, rpm is your friend. With reference to any normal 408-416 solid roller. With better flowing heads and more rpm 750 is not out of the question.
Last edited by *LSX RACING*; 08-03-2015 at 08:12 PM.
08-03-2015, 09:26 PM
#18
9.50's would likely be doable in my drag car with a 5500 converter and some more gear. It weighs 3200 also.
Either way it should be a blast
