new 434 combo HP predictions

[hymey]

Just thought i would post my proposed engine combo. Looking for HP estimates from this forum.
Maybe even some improvements.
Thanks.

Motown block
434 cu in
Scat crank 4" stroke x 4.155 bore
6" rods h beam rods
14.1 comp
235 AFR heads
shaft mount rollers 1.65 int 1.55exh
Super Victor (4500)
1050 QFT alky carb
comp cams solid roller 724/668 lift 279/286 dur @ 50 108 lobe sep.
Moroso vac pump.

I am building a LSX same bore and stroke my heads flow 418 cfm and have a 3.28" primary choke size so its for a big revver. Your heads are on the small side probably right for a 383ci or similiar. It will get to a point where it stops making power regardless of your cam, but more won't hurt it can only help. I have seen a similiar combo with a 255cc port volume, unsure of the choke but they flowed 350-360 cfm with 11:1 on pump fuel with 280s cam made 630hp but cranking compression was very low, he went to 13:1 and fitted a tunnel ram which raised the average cross section to move peak torque higher and make the head appear to look bigger lol. He ran two dominators on 102 octane unleaded and it made 797hp. The cross section for the heads were on the smaller side so it loved the extra volume in the runners. They put a lot of work into the single plane but still didnt have the avg cross section of the tunnel ram.

See how it goes your compression and cam is up there maybe the cyl heads need some work, with the engine being on the larger side it will respond a lot to cyl head, manifold, pipes.

cheers
7Al 3 msd ignition.

[mygtr]

Dyno booked 20th Aug. Will post results.

Couple of small changes, 280/286@50 Crane solid roller 726/711 lift 110 lobe sep. and a jesel belt drive.

[cuisinartvette]

Sounds like you might be disappointed skip the dyno send it to me and Ill drag that cross up the street for ya Enjoy!

[colebalster]

I predict a peak of 690 HP @ 6800-7000 RPM and a really flat torque curve of 640 LbFt. peak around 5400 RPM.

Just a guess.



Cole

[mikeyfrombc]

i would guess around 730hp 580/600ftlbs , i know my buddy,s old 434 with 18X heads and a similar compression and cam made around 750hp . his current 440 is over 715hp with way less cam and compression on 94octane with a 227T1 casting

[rustbucket79]

Funny how SBC heads were all that was available a few years back and they were fine, now there are several selections higher than 215's, and nothing is big enough any longer.

Looks like a good combo to me, heads might be a tick small considering the cubes and fuel used, but it should make pretty serious HP in the 6500 range I would think.

I was considering those heads until I knew I would want shaft rockers, then I decided to buy the 245's instead. I'm very interested in hearing the results of yours.

[ErnandezSS350]

Just thought i would post my proposed engine combo. Looking for HP estimates from this forum.
Maybe even some improvements.
Thanks.

Motown block
434 cu in
Scat crank 4" stroke x 4.155 bore
6" rods h beam rods
14.1 comp
235 AFR heads
shaft mount rollers 1.65 int 1.55exh
Super Victor (4500)
1050 QFT alky carb
comp cams solid roller 724/668 lift 279/286 dur @ 50 108 lobe sep.
Moroso vac pump.
7Al 3 msd ignition.

Very cool combo should make lots of power!

[ErnandezSS350]

Funny how SBC heads were all that was available a few years back and they were fine, now there are several selections higher than 215's, and nothing is big enough any longer.

.

I believe they say this because the big cubic inch size for a small block. If you look at a stock BBC head they are bigger than most small block heads, for the same 420-430 cubic inches .


Ernandez

[bigjoe1]

It sounds like some of you think that is a big cam.---Well, is NOT--- What I use is a big cam--- 289-304, with 873 valve lift. You have not even scratched the surface yet with that little cam


JOE SHERMAN RACING ENGINES

[RichardThiessen]

Funny how SBC heads were all that was available a few years back and they were fine, now there are several selections higher than 215's, and nothing is big enough any longer. .

Maybe head manufacturers didn't realize that even a 350 sbc could benefit from a 230 cc head until recently.

[mygtr]

Big Joe no disrespect but this is where these posts turn to shit.
HP predictions for my new 434 combo. Not how big my dick is.
Not everyone uses tunnel rams,Two carbs,massive valve springs
Ridiculously large cams to make 680-700 hp. I would imagine most
Of us are bracket racers who race on a budget and like minimal
maintenance. You seem to pop up all the time but offer no real informative
advice just telling us how good your engines are. What size cam would you use for
680-700hp??
And please little cam. Pffft

[bigjoe1]

Your cam selectionj is pretty good, and you will be right on target for what you are looking for


JOE SHERMAN RACING

[amc fan]

If you look on youtube.... Fred White engines has a video of dyno pull with a Dart shp 427 sbc with 247 degree hydraulic roller cam, with 220 afr heads, procomp intake ,and quick fuel 850 carb with HEI , on pump gas with 31 degrees timing it made like 650 hp at 6200 so your combo should be a peice of cake! you should be way over that no sweat!

[RichardThiessen]

If you look on youtube.... Fred White engines has a video of dyno pull with a Dart shp 427 sbc with 247 degree hydraulic roller cam, with 220 afr heads, procomp intake ,and quick fuel 850 carb with HEI , on pump gas with 31 degrees timing it made like 650 hp at 6200 so your combo should be a peice of cake! you should be way over that no sweat!

Wow... Talk about a happy dyno

[cpmotors]

Your cam selectionj is pretty good, and you will be right on target for what you are looking for


JOE SHERMAN RACING

lol