418" LS3 stroker with 237 Cathedrals heads to dyno
#1
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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.![Burnout](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_burnout.gif)
- 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.![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
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.
![Burnout](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_burnout.gif)
- 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.
![Happy](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_stretch.gif)
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#3
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Location: Coast of San Mateo County Between Pacifica & HMB
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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!
![Grin](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_grin.gif)
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!
![Grin](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_grin.gif)
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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#9
TECH Veteran
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What kind of car it's going in ?
#11
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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.
#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.
#18
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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