Our latest LT1 396
Melting Slicks
Joined: Mar 2008
Posts: 3,022
Likes: 3
From: Chandler Arizona
this is actually VERY impressive for stock case heads worked over by AI. This is PROOF that aftermarket heads are not necessarily needed. Unbelieveable! I didn't think I would see numbers like that from GM heads!
We need some more details on the intake end of this engine? Also ported stock Lt-1? mono-blade TB, dual's? injector size? engine management?
We need some more details on the intake end of this engine? Also ported stock Lt-1? mono-blade TB, dual's? injector size? engine management?
Burning Brakes
Joined: Jun 2000
Posts: 1,148
Likes: 48
If "skys the limit" on camshaft selection then yeah, I agree.
With aftermarket heads you can make the same power on a smaller engine with a cam that has almost 20 degrees less duration
, a smaller port for better part throttle response and 11:1 compression making the car MUCH more streetable.
Now don't get me wrong. What AI can do with a stock LT1 head is amazing and these are great numbers for any type of LT1 style cylinder head that's for sure but lets not just take peak numbers out of context when comparing stock heads to aftermarket.
One thing really cool about this project though is after he lays a beating on an unsuspecting C6, he can turn around and say "I'm just running stock heads too"
With aftermarket heads you can make the same power on a smaller engine with a cam that has almost 20 degrees less duration
, a smaller port for better part throttle response and 11:1 compression making the car MUCH more streetable. Now don't get me wrong. What AI can do with a stock LT1 head is amazing and these are great numbers for any type of LT1 style cylinder head that's for sure but lets not just take peak numbers out of context when comparing stock heads to aftermarket.
One thing really cool about this project though is after he lays a beating on an unsuspecting C6, he can turn around and say "I'm just running stock heads too"
Last edited by Vette Threat; Jun 30, 2009 at 08:21 PM.
Le Mans Master
Joined: Jul 2000
Posts: 5,012
Likes: 5
From: OKC OK
I'm not sure that I'd go that far, but I understand what you're saying. I'm also not sure that this is the thread to start another head debate either.
Former Vendor
Joined: Nov 2008
Posts: 146
Likes: 0
From: Virginia Beach Virginia
If "skys the limit" on camshaft selection then yeah, I agree.
With aftermarket heads you can make the same power on a smaller engine with a cam that has almost 20 degrees less duration, a smaller port for better part throttle response and 11:1 compression making the car MUCH more streetable.
Now don't get me wrong. What AI can do with a stock LT1 head is amazing and these are great numbers for any type of LT1 style cylinder head that's for sure but lets not just take peak numbers out of context when comparing stock heads to aftermarket.
One thing really cool about this project though is after he lays a beating on an unsuspecting C6, he can turn around and say "I'm just running stock heads too"
With aftermarket heads you can make the same power on a smaller engine with a cam that has almost 20 degrees less duration
, a smaller port for better part throttle response and 11:1 compression making the car MUCH more streetable. Now don't get me wrong. What AI can do with a stock LT1 head is amazing and these are great numbers for any type of LT1 style cylinder head that's for sure but lets not just take peak numbers out of context when comparing stock heads to aftermarket.
One thing really cool about this project though is after he lays a beating on an unsuspecting C6, he can turn around and say "I'm just running stock heads too"
these heads only have a 200cc intake runner,this setup is very streetable-people think that big duration cams arent streetable,with the correct lsa and icl you can make a big cam act like a much much smaller cam.the 350 ft lbs at 2500 rpm show how much power this engine makes under the curve not just peak numbers.I havent seen many aftermarket headed lt1's make any better power down low.This car drives like a dream-one of the best lt1's i've ever driven.
I got to thank Ed for putting a killer tune of this beast-he really knows how to make my engines shine.
Race Director
Joined: May 2003
Posts: 10,749
Likes: 41
these heads only have a 200cc intake runner,this setup is very streetable-people think that big duration cams arent streetable,with the correct lsa and icl you can make a big cam act like a much much smaller cam.the 350 ft lbs at 2500 rpm show how much power this engine makes under the curve not just peak numbers.I havent seen many aftermarket headed lt1's make any better power down low.This car drives like a dream-one of the best lt1's i've ever driven.
I got to thank Ed for putting a killer tune of this beast-he really knows how to make my engines shine.
I got to thank Ed for putting a killer tune of this beast-he really knows how to make my engines shine.
http://i488.photobucket.com/albums/r...N/scan0001.jpg
I am not trying to start a pissing match, but I have seen a few aftermarket LTx heads make just as much power down low as your 2xx cc head.
All in all that 471rwhp/439rwtq is excellent #'s.
Le Mans Master
Joined: Jul 2000
Posts: 5,012
Likes: 5
From: OKC OK
Not to push this head debate more, but IMO, its really more about having a well thought out package/system/plan whatever you call it, attention to detail, and good solid tuning. There are so many little variables that work against us with these cars/motors, and its more about getting every running "right". Also, IMO, given the bore, stroke, and rpm (CFM requirements) their isn't a perfect or ideal head (or cam) with any one of these motors...look at each car/motor...air filter to exhaust tip...they each have their own system that works for them...and makes power! Not counting all the F-body guys, here are a couple of corvette cases that kinda show my point...
Denny Mclain? got over 480rwhp several times with ported TFS heads. (396ci)
Zix got 465+rwhp with ported LT4s (383ci)
Mark Bychowski got 475rwhp with AFR 210s (370ci)
This car (f-body) got 470rwhp with LT1s (396ci)
VetteThreat got 464rwhp with AFR 195s (383ci)
I think some of you guys are looking for the magical part and missing the bigger picture...
Denny Mclain? got over 480rwhp several times with ported TFS heads. (396ci)
Zix got 465+rwhp with ported LT4s (383ci)
Mark Bychowski got 475rwhp with AFR 210s (370ci)
This car (f-body) got 470rwhp with LT1s (396ci)
VetteThreat got 464rwhp with AFR 195s (383ci)
I think some of you guys are looking for the magical part and missing the bigger picture...
Melting Slicks
Joined: Mar 2008
Posts: 3,022
Likes: 3
From: Chandler Arizona
guys- apparently my comment hit a "soft" spot.
I'm not saying these heads and "end all, be all", i just wanted to state that these are solid numbers and decent "power under the curve" for a stock head 396 combo! I really thought the Lt-x heads would be choking this combination, but it's done VERY well!
I also agree, the cam is large, but it's worked very well with this combination.
I'm not saying these heads and "end all, be all", i just wanted to state that these are solid numbers and decent "power under the curve" for a stock head 396 combo! I really thought the Lt-x heads would be choking this combination, but it's done VERY well!
I also agree, the cam is large, but it's worked very well with this combination.
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Former Vendor
Joined: Nov 2008
Posts: 146
Likes: 0
From: Virginia Beach Virginia
let me tell you how all of this came about.customer comes to us and wants a 396 shortblock,he wants to transfer his AI 200 heads off his 383 and has the ebelbrock intake.He then states he wants 450 to the tires.I had never used the AI heads before and had no idea how well they worked-i had flow numbers but that doesn't mean much.So basically i figured i would error to the high side and put a little more cam and compression to make sure i made the 450 to the tires.After Ed got it tuned we were really happy with the numbers and how well the heads worked.
I am not saying that these heads are the end all,they were what i had to work with and i was pleasantly surprised in the end.A set of aftermarket heads will always be better-but the are pretty damn good for a gm casting.
thanks for all the compliments
I am not saying that these heads are the end all,they were what i had to work with and i was pleasantly surprised in the end.A set of aftermarket heads will always be better-but the are pretty damn good for a gm casting.
thanks for all the compliments
Racer
Joined: Aug 2007
Posts: 305
Likes: 1
From: DRAYTON VALLEY ALBERTA
I think if an american machinist is going to foot the bill for all american parts, then I will use all american parts. Until then I will use what is the best bang for my buck, because I have to live too. I will stay/live right where im at and save as much money as I can while doing so.
Melting Slicks
Joined: Mar 2008
Posts: 3,022
Likes: 3
From: Chandler Arizona
let me tell you how all of this came about.customer comes to us and wants a 396 shortblock,he wants to transfer his AI 200 heads off his 383 and has the ebelbrock intake.He then states he wants 450 to the tires.I had never used the AI heads before and had no idea how well they worked-i had flow numbers but that doesn't mean much.So basically i figured i would error to the high side and put a little more cam and compression to make sure i made the 450 to the tires.After Ed got it tuned we were really happy with the numbers and how well the heads worked.
I am not saying that these heads are the end all,they were what i had to work with and i was pleasantly surprised in the end.A set of aftermarket heads will always be better-but the are pretty damn good for a gm casting.
thanks for all the compliments
I am not saying that these heads are the end all,they were what i had to work with and i was pleasantly surprised in the end.A set of aftermarket heads will always be better-but the are pretty damn good for a gm casting.
thanks for all the compliments
AI has done an incredible job working these heads over.
I think a lot of us Lt-x owners tend to get the impression that you "NEED" aftermarket heads for a solid streetable build.
although this has "more compression and cam" than the vast majority would have used on the street, it does go to show that the stock GM castings (worked over) can get the job done. That's what I mean when I said this proves that an aftermarket head is not necessarily necessary...lol.
Race Director
Joined: May 2003
Posts: 10,749
Likes: 41
Not to push this head debate more, but IMO, its really more about having a well thought out package/system/plan whatever you call it, attention to detail, and good solid tuning. There are so many little variables that work against us with these cars/motors, and its more about getting every running "right". Also, IMO, given the bore, stroke, and rpm (CFM requirements) their isn't a perfect or ideal head (or cam) with any one of these motors...look at each car/motor...air filter to exhaust tip...they each have their own system that works for them...and makes power! Not counting all the F-body guys, here are a couple of corvette cases that kinda show my point...
Denny Mclain? got over 480rwhp several times with ported TFS heads. (396ci)
Zix got 465+rwhp with ported LT4s (383ci)
Mark Bychowski got 475rwhp with AFR 210s (370ci)
This car (f-body) got 470rwhp with LT1s (396ci)
VetteThreat got 464rwhp with AFR 195s (383ci)
I think some of you guys are looking for the magical part and missing the bigger picture...
Denny Mclain? got over 480rwhp several times with ported TFS heads. (396ci)
Zix got 465+rwhp with ported LT4s (383ci)
Mark Bychowski got 475rwhp with AFR 210s (370ci)
This car (f-body) got 470rwhp with LT1s (396ci)
VetteThreat got 464rwhp with AFR 195s (383ci)
I think some of you guys are looking for the magical part and missing the bigger picture...
I think the tuning aspect is overlooked as well.
It just isnt easy to dyno over 450rwhp period with an LTx or a Gen1 with a hyd. roller.
Thread Starter
Melting Slicks
Joined: Jul 2006
Posts: 3,356
Likes: 1
From: Chesapeake Va
Here is the most recent LTx dyno on this forum, and as you see it's an aftermarket cylinder head. If you notice it has a flatter torque curve, and is a smaller cylinder head with less cubes, and only a compression ratio of 11.3.
http://i488.photobucket.com/albums/r...N/scan0001.jpg
I am not trying to start a pissing match, but I have seen a few aftermarket LTx heads make just as much power down low as your 2xx cc head.
All in all that 471rwhp/439rwtq is excellent #'s.
http://i488.photobucket.com/albums/r...N/scan0001.jpg
I am not trying to start a pissing match, but I have seen a few aftermarket LTx heads make just as much power down low as your 2xx cc head.
All in all that 471rwhp/439rwtq is excellent #'s.
As for aftermarket cylinder heads, I spoke with Phil of AI yesterday, and apparently this set of heads is 3 years old, and subsequently is a bit older technology wise. They now have an updated version which he explained would work even better.
As Shawn stated, this was a 'work with what we got' kinda job. The numbers were better than either of us expected. Had we been looking to do a max effort build we would have done some things differently. True duals, port the intake (it's out of the box) mono blade as opposed to 58mm, etc.
As for the size of the cam and driveability, it drives extremely well.
Race Director
Joined: May 2003
Posts: 10,749
Likes: 41
That motor is making the same torque down low as the one we posted. It just doesn't peak as high. Also worth noting, is the F-body exhaust is 3 inch single, as opposed to Y-body dual exhaust. I'm sure this motor in a Y-body would make a pretty good chunk more.
As for aftermarket cylinder heads, I spoke with Phil of AI yesterday, and apparently this set of heads is 3 years old, and subsequently is a bit older technology wise. They now have an updated version which he explained would work even better.
As Shawn stated, this was a 'work with what we got' kinda job. The numbers were better than either of us expected. Had we been looking to do a max effort build we would have done some things differently. True duals, port the intake (it's out of the box) mono blade as opposed to 58mm, etc.
As for the size of the cam and driveability, it drives extremely well.
As for aftermarket cylinder heads, I spoke with Phil of AI yesterday, and apparently this set of heads is 3 years old, and subsequently is a bit older technology wise. They now have an updated version which he explained would work even better.
As Shawn stated, this was a 'work with what we got' kinda job. The numbers were better than either of us expected. Had we been looking to do a max effort build we would have done some things differently. True duals, port the intake (it's out of the box) mono blade as opposed to 58mm, etc.
As for the size of the cam and driveability, it drives extremely well.
There is no doubt that this motor is making great power! Job well done.
I don't know if it was asked or not, but what was the LSA and lift of the cam?
