LT1 396/406 stroker....need help!!!
Thread Starter
Burning Brakes
Joined: May 2002
Posts: 831
Likes: 0
From: Iowa City IA
LT1 396/406 stroker....need help!!!
gonna build a 396 stroker unless i can find someone who sells 4.060" pistons, then ill do a 406. a few questions for you guys....what kind of compression can i get away with? will the LT1 manifold be up to the task once its ported? if i go with AFR heads...what size runners? i need MASSIVE power out of this thing.....thanks in advance :cheers:
Safety Car
Joined: Mar 2000
Posts: 3,620
Likes: 2
From: Hillsboro OR
Re: LT1 396/406 stroker....need help!!! (kawboy5792)
How massive are we talking for hp ?
SRP makes 4.060 pistons which I am using now. I'd use 4.030 and give up the 5 cubic inches if I were you. I went larger because I had some cylinder bore problems which retrospect probably didn't require an overbore but I didn't have a good machinest like I do now.
You don't need to port the LT1 intake. Its probably good for 7000 rpm the way it is. Go with AFR 190 heads, the larger ones do not flow enough to justfiy the extra runner volume until you get to 227 or the raised port ones which require a special intake and cost 3000 bucks. I have gotten up to 550 hp on desktop dyno using the stock flow specs of the AFR 190s with open exhuast and headers.
Compression depends upon the cam you use. SpeedDemon says you can go to 12:1 and I know glock94 is running 11.5. I think 11 is safely doable since the LT4 runs 10.8. You maybe able to get to 11.5 without to much trouble but I would shoot for a bit lower for safety. The ZR1 runs with 11.5 but its a complete aluminum block and head design.
SRP makes 4.060 pistons which I am using now. I'd use 4.030 and give up the 5 cubic inches if I were you. I went larger because I had some cylinder bore problems which retrospect probably didn't require an overbore but I didn't have a good machinest like I do now.
You don't need to port the LT1 intake. Its probably good for 7000 rpm the way it is. Go with AFR 190 heads, the larger ones do not flow enough to justfiy the extra runner volume until you get to 227 or the raised port ones which require a special intake and cost 3000 bucks. I have gotten up to 550 hp on desktop dyno using the stock flow specs of the AFR 190s with open exhuast and headers.
Compression depends upon the cam you use. SpeedDemon says you can go to 12:1 and I know glock94 is running 11.5. I think 11 is safely doable since the LT4 runs 10.8. You maybe able to get to 11.5 without to much trouble but I would shoot for a bit lower for safety. The ZR1 runs with 11.5 but its a complete aluminum block and head design.
Burning Brakes
Joined: Mar 1999
Posts: 876
Likes: 9
From: Mooresville NC
Re: LT1 396/406 stroker....need help!!! (kawboy5792)
4.060 pistons aren't a problem like AquaMetalic said. That would give you 401 cid, but I would agree again that you might as well stick with the 4.030 and leave some room for future bores.
For heads, I would consider what RPM you are shooting for. If you want to make peak power down around 5200 RPM, 190-195's will work well. If you are looking to shift up at 6500 with 396 cubes, you will probably want 210's. Otherwise the velocity becomes the restrictive part.
For heads, I would consider what RPM you are shooting for. If you want to make peak power down around 5200 RPM, 190-195's will work well. If you are looking to shift up at 6500 with 396 cubes, you will probably want 210's. Otherwise the velocity becomes the restrictive part.
Burning Brakes
Joined: Mar 1999
Posts: 876
Likes: 9
From: Mooresville NC
Re: LT1 396/406 stroker....need help!!! (Ramrod92)
I've been pretty slackard in updating the sight, been too busy anymore. I'm sure you have noticed you don't see me on the forum hardly at all any more.
But, the reality is, not much has changed with Hoover. I drive and race it regularly, but really haven't put any money into it since 2000. I think the main changes that people have mensioned in email is that i now have shaft rockers http://www.myphotosonline.biz:8080/p...2FShaftRockers and Comp Cams valve springs. I think my only upgrade for all of 2001 was an oil cooler, oil gets hot during these southern summers with the AC on. The car has been really good to me, I haven't even freshened the trans since April 2000.
On the flip side the itch has been on me again. I am planning an 18° motor for this winter. :D
But, the reality is, not much has changed with Hoover. I drive and race it regularly, but really haven't put any money into it since 2000. I think the main changes that people have mensioned in email is that i now have shaft rockers http://www.myphotosonline.biz:8080/p...2FShaftRockers and Comp Cams valve springs. I think my only upgrade for all of 2001 was an oil cooler, oil gets hot during these southern summers with the AC on. The car has been really good to me, I haven't even freshened the trans since April 2000.
On the flip side the itch has been on me again. I am planning an 18° motor for this winter. :D
Melting Slicks
Joined: Aug 2000
Posts: 2,388
Likes: 42
From: Murrysville PA
Re: LT1 396/406 stroker....need help!!! (KLLRVET)
I also give my vote for the 4.030" bore and 396 cid. Leave room for a future bore. As for compression, there will be many opinions. My opinion for street use and not mostly race, 11:1 is a safe bet.
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Racer
Joined: Oct 2001
Posts: 444
Likes: 0
Re: LT1 396/406 stroker....need help!!! (LT401Vette)
I am planning an 18° motor for this winter. :D
Le Mans Master
Joined: Jan 1999
Posts: 5,134
Likes: 23
From: Long Island NY
Re: LT1 396/406 stroker....need help!!! (JB'S LT4)
Can you guys give me a lesson on 18* heads.
What degree are standard heads?
Why can they make so much more power than std heads (750 na)?
Thanks
What degree are standard heads?
Why can they make so much more power than std heads (750 na)?
Thanks
Racer
Joined: Oct 2001
Posts: 444
Likes: 0
Re: LT1 396/406 stroker....need help!!! (Hammer)
LT1 or any stock sbc heads are 23 degree.....where the HP advantage comes in to play is the 18 degree valve angle, meaning the valves are more parralle to the piston, a 18 degree head also has alot smaller combustion chambers, the total redesign of the valve angle allows for the use of taller raised Intake ports..basicly the head is capeable of flowing in the 380-390 cfm range on the intake, about the maximum you will ever find a 23 degree head flowing in in the 330-340 cfm range...40-50cfm of flow is bunches and bunches of Mucho Horse Power :yesnod: ..................currently nobody makes a 18 degree head for a LT1/4 Motor but it can be done :yesnod:
[Modified by JB'S LT4, 8:19 PM 8/7/2002]
[Modified by JB'S LT4, 8:19 PM 8/7/2002]
