(L99) 4.3L V8 (Possibly Building A Stroker...)
12-23-2017, 02:09 PM
#1
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Thread Starter
(L99) 4.3L V8 (Possibly Building A Stroker...) First off. Don't want any Negative Comments. Not here for that. I've learned that my 4.3L Block does have a Stock 9.025 Deck Height. I also learned that it has a Factory 305 SBC Bore. I had in mind maybe doing a 3.48 Crank, 5.7 Rod and then it would be an LT Based 305. But what I have seen along with that is people doing a 334 Stroker SBC. Why wouldn't I be able to do this? Been thinking heavy on it. 3.75 Crank, 1 Piece Rear Main Seal. Then a 30 Thousandths over Piston. Just confused if I should use a 5.7 Rod or not with that Stroke Crank. Thoughts?
12-23-2017, 07:17 PM
#3
Wanna be different? Cool.
Actually, the L99 had a 3.736" bore where as the 305ci had a 3.700 bore.
You can use the same rotating assembly as you would use in a stroker LT1, but you'd have to use custom pistons.....
I mean, you can't just put in a different crank and rods and use the same pistons.
And AFAIK, there are no off the shelf pistons for a 3.736" or a 3.766" bore that will go with a 3.75" crank with 5.7" or 6" rods.
KW
Actually, the L99 had a 3.736" bore where as the 305ci had a 3.700 bore.
You can use the same rotating assembly as you would use in a stroker LT1, but you'd have to use custom pistons.....
I mean, you can't just put in a different crank and rods and use the same pistons.
And AFAIK, there are no off the shelf pistons for a 3.736" or a 3.766" bore that will go with a 3.75" crank with 5.7" or 6" rods.
KW
12-23-2017, 07:27 PM
#4
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12-25-2017, 11:31 AM
#10
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Thread Starter
That makes it 305 Cubic Inches my Friend. With a 9.025 Deck Height, 3.736 Bore, 3.48 Stroke, 5.7 Rod. That makes it a 305 LTx my man. Calculator says so, before we get into a Pissing Contest over it lol. 😂😂😂😂
12-25-2017, 08:28 PM
#12
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Well, from what I have seen, nobody else has made a 334 Cube LTx Stroker before out of an L99. I want to be that guy and do it Successfully my man. That's all. Make decent Power and move this Caprice around Spiritually. Nothing crazy. Just a Balanced and Blueprinted 334 LTx that can Rev 7,000 RPM with no issue. Which means Strong Rod Bolts (ARP 625's) and Balancing to the Max and have decent flowing Heads up top. Not trying to Gap nobody up. Just a Fun Caprice with the First Stroked to 334 Cube L99.
12-25-2017, 08:49 PM
#14
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I don't plan on beating the ***** out of my Car everyday like that. Just there when I need it. Casual Drive. Maybe Small (Skert, Skert) every now and then lol.
12-25-2017, 09:52 PM
#15
Village Troll 
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You will be disappointed. If not at first, a short time later. Especially after you get beat by stock 4cyl. imports all the time. Everyone will wonder why your **** is so slow. Don’t do it, son.
12-26-2017, 07:02 AM
#16
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Thread Starter
Why not? Only thing I lack is a 4 Inch Bore like a Regular 350 SBC. Will actually have the same Stroke as a 383 Stroker being 3.750. Jumping to Conclusions ain't cool man. Not at all.
12-26-2017, 07:14 AM
#17
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Thread Starter
Also need to keep in mind, my Heads flow way better then a Gen 1 SBC and will be Ported and Polished. I mean it's a 3.750 Stroked Gen 2 we Talking about. What in your Head makes you think my Car will be an absolute Turd? What, a 3.736 Bored to a 3.766 Cylinder Diameter?
12-26-2017, 10:06 AM
#18
Village Troll
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I'm telling you, if what you're trying actually made power it would've been done long ago.
12-26-2017, 11:19 AM
#19
It seems like you don't have crazy high specific goals, so if you want to have fun and be different, go for it.
Just keep in mind performance will likely not be what you expect, since you seem to be building a high strung, high RPM, small V8 for a big heavy car that wants power under the curve and lots of torque to get moving. Basically a motor that would be more at home in a 2500lb RX7 body instead of a massive 4+ Caprice.
Personally, I would consider two routes:
- If you are dead set on keeping that motor, and are on more of a budget, I would go as large as safely possible (likely 40-60 over - Gizmo has gone 60 over an an L99 but it was drag only so 40 would be the safe bet). Use a good medium sized torquey cylinder head like the 21* trickflow heads or ported stockers, and at MAX a mid 230s duration cam. You will make likely close to 330-350rwhp without getting too expensive. It will want to rev...expect to use most of the stock ECUs 7200 rpm limit.
- Second choice, a lot more expensive but will make a ton more power, is to take your L99 crank and throw it into an LT1 block for a destroked LT1. I know you don't want to ditch your block for whatever reason, but destroking an LT1 makes a hell of a lot more sense then stroking an L99. This gives you the bigger bore for much better cylinder head selection, easier to source pistons, and a short stroke for a crazy high RPM monster. You will need better heads then the other build, an aftermarket ECU will be a must to get the RPMs you will need, and I would also run shaftmount rockers as well. Don't forget supporting mods will be more expensive as well - stronger pushrods, quality hub+damper, etc. I would aim for 8,000 RPM, and to be honest I would go with a tight lash HIPPO solid roller. It will be very expensive, but likely sound like nothing else and be a pretty cool build...although more at home road racing in a light car then a big heavy caprice.
To be clear, I think both choices are terrible price:performance and wouldn't recommend either - but I am just trying to provide the information you are asking for
. None of us can talk too much **** about not being worth it to mod a motor when we use boat anchor LT1s vs a junkyard LQ9 6 liter LS that can be had for pennies and make insane power for a fraction of what an LT1 would cost to match.
Just keep in mind performance will likely not be what you expect, since you seem to be building a high strung, high RPM, small V8 for a big heavy car that wants power under the curve and lots of torque to get moving. Basically a motor that would be more at home in a 2500lb RX7 body instead of a massive 4+ Caprice.
Personally, I would consider two routes:
- If you are dead set on keeping that motor, and are on more of a budget, I would go as large as safely possible (likely 40-60 over - Gizmo has gone 60 over an an L99 but it was drag only so 40 would be the safe bet). Use a good medium sized torquey cylinder head like the 21* trickflow heads or ported stockers, and at MAX a mid 230s duration cam. You will make likely close to 330-350rwhp without getting too expensive. It will want to rev...expect to use most of the stock ECUs 7200 rpm limit.
- Second choice, a lot more expensive but will make a ton more power, is to take your L99 crank and throw it into an LT1 block for a destroked LT1. I know you don't want to ditch your block for whatever reason, but destroking an LT1 makes a hell of a lot more sense then stroking an L99. This gives you the bigger bore for much better cylinder head selection, easier to source pistons, and a short stroke for a crazy high RPM monster. You will need better heads then the other build, an aftermarket ECU will be a must to get the RPMs you will need, and I would also run shaftmount rockers as well. Don't forget supporting mods will be more expensive as well - stronger pushrods, quality hub+damper, etc. I would aim for 8,000 RPM, and to be honest I would go with a tight lash HIPPO solid roller. It will be very expensive, but likely sound like nothing else and be a pretty cool build...although more at home road racing in a light car then a big heavy caprice.
To be clear, I think both choices are terrible price:performance and wouldn't recommend either - but I am just trying to provide the information you are asking for
. None of us can talk too much **** about not being worth it to mod a motor when we use boat anchor LT1s vs a junkyard LQ9 6 liter LS that can be had for pennies and make insane power for a fraction of what an LT1 would cost to match.