Engine guys, 23 deg 700hp heads needed
Thread Starter
Racer
Joined: Jan 2010
Posts: 367
Likes: 1
From: Christchurch Canterbury
Engine guys, 23 deg 700hp heads needed
Hi,
Anyone know of 23 deg Iron heads that will support 700+hp.
They are for a historic racing class, max cu 410 and must run 23 deg iron heads, induction must fit under stock hood.
Cheers
Anyone know of 23 deg Iron heads that will support 700+hp.
They are for a historic racing class, max cu 410 and must run 23 deg iron heads, induction must fit under stock hood.
Cheers
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
Pretty tall order. Can you run racing fuel? If so Enginequest 235 heads flow over 310 CFM and flow to over .700 lift. You will need to port them a little , run over 14 to 1 compression, spin it to 7500 or better and have a solid roller cam with over .700 lift and ability to pull to 7500 RPM to top 700 HP. This will be expensive but the heads are reasonable for what you get. I think CNC Motorsports sells them and has in house porting service. Check on valve configuration. Might require offset rockers or lifter bores These are big. Go 3.80 stroke 4.145 bore for 410 CI. custom pistons or 3.75 stroke 4.155 bore for 407 CI, Off the shelf pistons. Whatever you use you will likely have to cut the pistons for valve clearance. The intake fitting under the stock hood will open another can of worms. What kind of car and what hood?
http://forums.corvetteforum.com/c3-t...q-406-a-2.html
http://forums.corvetteforum.com/c3-t...q-406-a-2.html
Last edited by 63mako; Jul 3, 2012 at 09:44 PM. Reason: added link
Le Mans Master
Joined: May 2006
Posts: 9,993
Likes: 1,136
From: League City Tx
Not likely that any out of the box 23* head is gonna get you there. You will HAVE to have some serious port/bowl work done. You will have to get them CSA sized right for the size/rpm range of the engine.
We are doing a 650hp pump gas, HYD roller 427" small block build right now. We started with bare casting RHS 235s and doing quite a bit of port work on them. We still can't get the CSA where we need it due to push rod pinch but we're working on it. Also using a Bret Bauer custom grind HYD roller, the new Super Victor intake with a bunch of plenum work.
Last year we did a 420", 11.2-1, pump gas, HYD roller combo using some old Dart 230 castings and we did a bunch of port work to them...actually broke through in some places and had to weld them.. They ended up in the 245 cc range and flowed in the 330s. Ported Super Vic, 3" of carb spacers, 1 7/8" headers. That motor made 640hp on 93 oct. Runs 136 mph in a 3100lb camaro.
700 HP out of 410" will be tough but do able since you don't have to run it on pump gas... Lots of compression, lots of cam, lots of RPMs... Won't be cheap...
We are doing a 650hp pump gas, HYD roller 427" small block build right now. We started with bare casting RHS 235s and doing quite a bit of port work on them. We still can't get the CSA where we need it due to push rod pinch but we're working on it. Also using a Bret Bauer custom grind HYD roller, the new Super Victor intake with a bunch of plenum work.
Last year we did a 420", 11.2-1, pump gas, HYD roller combo using some old Dart 230 castings and we did a bunch of port work to them...actually broke through in some places and had to weld them.. They ended up in the 245 cc range and flowed in the 330s. Ported Super Vic, 3" of carb spacers, 1 7/8" headers. That motor made 640hp on 93 oct. Runs 136 mph in a 3100lb camaro.
700 HP out of 410" will be tough but do able since you don't have to run it on pump gas... Lots of compression, lots of cam, lots of RPMs... Won't be cheap...
Last edited by ajrothm; Jul 3, 2012 at 10:27 PM.
Thread Starter
Racer
Joined: Jan 2010
Posts: 367
Likes: 1
From: Christchurch Canterbury
Pretty tall order. Can you run racing fuel? If so Enginequest 235 heads flow over 310 CFM and flow to over .700 lift. You will need to port them a little , run over 14 to 1 compression, spin it to 7500 or better and have a solid roller cam with over .700 lift and ability to pull to 7500 RPM to top 700 HP. The intake fitting under the stock hood will open another can of worms. This will be expensive but the heads are reasonable for what you get. I think CNC Motorsports sells them and has in house porting service. Check on valve configuration. Might require offset rockers or lifter bores These are big. Go 3.80 stroke 4.145 bore for 410 CI. custom pistons or 3.75 stroke 4.155 bore for 407 CI, Off the shelf pistons. Whatever you use you will likely have to cut the pistons for valve clearance.
http://forums.corvetteforum.com/c3-t...q-406-a-2.html
http://forums.corvetteforum.com/c3-t...q-406-a-2.html
Yes will be race gas, most don't run more the 12:5 comp.
I thought some circle track classes have iron head rules ?
Thread Starter
Racer
Joined: Jan 2010
Posts: 367
Likes: 1
From: Christchurch Canterbury
You can run a big block if the car cam from factory with one, so 454cu, 60 thou over, but either iron heads or in the case of 69 camao or corvette, GM l88 replacement parts but no porting allowed
Thread Starter
Racer
Joined: Jan 2010
Posts: 367
Likes: 1
From: Christchurch Canterbury
Pretty tall order. Can you run racing fuel? If so Enginequest 235 heads flow over 310 CFM and flow to over .700 lift. You will need to port them a little , run over 14 to 1 compression, spin it to 7500 or better and have a solid roller cam with over .700 lift and ability to pull to 7500 RPM to top 700 HP. This will be expensive but the heads are reasonable for what you get. I think CNC Motorsports sells them and has in house porting service. Check on valve configuration. Might require offset rockers or lifter bores These are big. Go 3.80 stroke 4.145 bore for 410 CI. custom pistons or 3.75 stroke 4.155 bore for 407 CI, Off the shelf pistons. Whatever you use you will likely have to cut the pistons for valve clearance. The intake fitting under the stock hood will open another can of worms. What kind of car and what hood?
http://forums.corvetteforum.com/c3-t...q-406-a-2.html
http://forums.corvetteforum.com/c3-t...q-406-a-2.html
http://www.racingheadservice.com/Cyl...st%20Iron.aspx
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
I would read the rules very closely. especially where it talks about angle milling, altered valve spacing, and chamber welding.
angle milling can change heads valve degree to 20 degrees. chamber welding and altered valve spacing can increase valve sizes to 2.15 intakes and intake ports exceeding 240 cc and flow rates around 345 cfm.
The ones I have seen started with 227 or 230 degree Dart iron heads. I would also ask what dart does in the way of options on the 227 cc
Then when it gets into cheater heads. They have magnetic paint coating and non spread port 18 degree aluminum racing heads that pass the test to the casual tech inspector
http://www.dartheads.com/products/ai...itfile_id/109/
angle milling can change heads valve degree to 20 degrees. chamber welding and altered valve spacing can increase valve sizes to 2.15 intakes and intake ports exceeding 240 cc and flow rates around 345 cfm.
The ones I have seen started with 227 or 230 degree Dart iron heads. I would also ask what dart does in the way of options on the 227 cc
Then when it gets into cheater heads. They have magnetic paint coating and non spread port 18 degree aluminum racing heads that pass the test to the casual tech inspector
http://www.dartheads.com/products/ai...itfile_id/109/
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Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
63mako, in this case 69 camaro, allowed to use factor production cowl hood, I see RHS do these heads, any good ??
http://www.racingheadservice.com/Cyl...st%20Iron.aspx
http://www.racingheadservice.com/Cyl...st%20Iron.aspx
Thread Starter
Racer
Joined: Jan 2010
Posts: 367
Likes: 1
From: Christchurch Canterbury
I would read the rules very closely. especially where it talks about angle milling, altered valve spacing, and chamber welding.
angle milling can change heads valve degree to 20 degrees. chamber welding and altered valve spacing can increase valve sizes to 2.15 intakes and intake ports exceeding 240 cc and flow rates around 345 cfm.
The ones I have seen started with 227 or 230 degree Dart iron heads. I would also ask what dart does in the way of options on the 227 cc
Then when it gets into cheater heads. They have magnetic paint coating and non spread port 18 degree aluminum racing heads that pass the test to the casual tech inspector
http://www.dartheads.com/products/ai...itfile_id/109/
angle milling can change heads valve degree to 20 degrees. chamber welding and altered valve spacing can increase valve sizes to 2.15 intakes and intake ports exceeding 240 cc and flow rates around 345 cfm.
The ones I have seen started with 227 or 230 degree Dart iron heads. I would also ask what dart does in the way of options on the 227 cc
Then when it gets into cheater heads. They have magnetic paint coating and non spread port 18 degree aluminum racing heads that pass the test to the casual tech inspector
http://www.dartheads.com/products/ai...itfile_id/109/
3.6 Engine:
(1) Cylinder head(s) and block must be of “Standard” material and may be changed to one of the same make and model range but cylinder heads must be of the same internal valve angle, port spacing and. Aftermarket “Substitute Part” blocks and heads are allowed. Alloy heads and blocks are not allowed unless original fitment and meet the “Production Series” criteria. Special Note: See below
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
With those set of rules and you intending to keep in the spirit of them. I would asks Dart opinion on what is best. But it will probably be something like the 230 head angle milled to a subtle 21 degree. Hardly noticable without a motor tear down. Get the chamber down to 50 cc. Then standard forged flat tops can get you to high 13 to 1 C/R
2.10 or 2.12 intakes For the exhaust run commom header adapters for headers with 2 or 2 1/8th primary pipes.
We never found a stamped lifter that would not break with big solid cam lifts and durations. Most everbody in Historic racing uses Ford big block stamped lifters because they are super stong compared to Chevy stock stamped. To be in the spirit of the rules we found a guy to make lifters for us. He removes the roller tip from Comp Cams roller tipped rockers and replaces it with a non roller end. They have never broken where the big fords was an on going problem in high 7000 rpm motors.
I would find out if one of the lower rise Weiand single plane intakes would pass. Like the 7531
2.10 or 2.12 intakes For the exhaust run commom header adapters for headers with 2 or 2 1/8th primary pipes.
We never found a stamped lifter that would not break with big solid cam lifts and durations. Most everbody in Historic racing uses Ford big block stamped lifters because they are super stong compared to Chevy stock stamped. To be in the spirit of the rules we found a guy to make lifters for us. He removes the roller tip from Comp Cams roller tipped rockers and replaces it with a non roller end. They have never broken where the big fords was an on going problem in high 7000 rpm motors.
I would find out if one of the lower rise Weiand single plane intakes would pass. Like the 7531
Thread Starter
Racer
Joined: Jan 2010
Posts: 367
Likes: 1
From: Christchurch Canterbury
With those set of rules and you intending to keep in the spirit of them. I would asks Dart opinion on what is best. But it will probably be something like the 230 head angle milled to a subtle 21 degree. Hardly noticable without a motor tear down. Get the chamber down to 50 cc. Then standard forged flat tops can get you to high 13 to 1 C/R
2.10 or 2.12 intakes For the exhaust run commom header adapters for headers with 2 or 2 1/8th primary pipes.
We never found a stamped lifter that would not break with big solid cam lifts and durations. Most everbody in Historic racing uses Ford big block stamped lifters because they are super stong compared to Chevy stock stamped. To be in the spirit of the rules we found a guy to make lifters for us. He removes the roller tip from Comp Cams roller tipped rockers and replaces it with a non roller end. They have never broken where the big fords was an on going problem in high 7000 rpm motors.
I would find out if one of the lower rise Weiand single plane intakes would pass. Like the 7531
2.10 or 2.12 intakes For the exhaust run commom header adapters for headers with 2 or 2 1/8th primary pipes.
We never found a stamped lifter that would not break with big solid cam lifts and durations. Most everbody in Historic racing uses Ford big block stamped lifters because they are super stong compared to Chevy stock stamped. To be in the spirit of the rules we found a guy to make lifters for us. He removes the roller tip from Comp Cams roller tipped rockers and replaces it with a non roller end. They have never broken where the big fords was an on going problem in high 7000 rpm motors.
I would find out if one of the lower rise Weiand single plane intakes would pass. Like the 7531
intake is down to what ever can be massaged to fit under the hood.
Our rules here seem to be much "more liberal" that your historic racing rules
Cheers
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
For reliability have the block lifter bores increased to .875 diameter or even .904 Bigger lifter wheels last longer
Last edited by gkull; Jul 4, 2012 at 02:07 AM.