L-98 engine block ?
Thread Starter
Racer
Joined: Jul 2002
Posts: 447
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From: Malta Europe
L-98 engine block ?
As some of you read my other post !! I am thinking of buying a stroker kit for my 88 vette !! I want big gains so I am thinking of doing the 427ci stroker kit from summit !! but I have a few questions that I like to ask becouse I am lost on this one summit says that you need spechial cam shaft on this kit so I send them an E-mail and they said that you need this =cam requrements of .870" base circle and 109 degree intake centerline !!!1)what does that mean ?? this cam shaft is $429.95 from summit and you need to bore the block to 4.125" to make this kit works !!! so I have a question of both !! 2)Can the L-98 can be bored to 4.125" ?? 3) or I need to use a different block for this set up ?? 4)Can the stock computer can handle all of these changes with a custom chip ?? and please 5)explain the cam shaft part becouse I wished that I could use the ZZ9X cam on this one !!! please explain to me becouse I am lost Thank you in advance !!
Drifting
Joined: Aug 2000
Posts: 1,805
Likes: 36
From: Annapolis MD
Re: L-98 engine block ? (marlon88)
They are refering to needing a "small base circle" cam to clear that long of a stroke in a small block. If you think of a cam as a circle with a "lobe" added to it, the small base circle means that the "circle" part of the cam is smaller. This is needed with the long 4" stroke in a small block Chevy so that the connecting rods will clear.
I seriously doubt you can bore most 350 block castings to 4.125" and still have thick enough cylinder walls. For a 427" small block IMO you will be money ahead in the long run to go with an aftermarket block.
I'd seriously look at the Motown 427" short block from http://www.theengineshop.com/sbkits3.shtml as I doubt you can build your own for their cost.
Good Luck - Greg
I seriously doubt you can bore most 350 block castings to 4.125" and still have thick enough cylinder walls. For a 427" small block IMO you will be money ahead in the long run to go with an aftermarket block.
I'd seriously look at the Motown 427" short block from http://www.theengineshop.com/sbkits3.shtml as I doubt you can build your own for their cost.
Good Luck - Greg
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: L-98 engine block ? (GregP)
.060 is the max you'll want to go on a L98 block, and even then you're at the limit. Most guys only go .030 to make sure there's enought meat left in the block.
Even at .060 you wouldn't be even half way to what you need at 4.125, so you can forget the L98 with that much bore.
There are other choices though, a 400 block or an aftermarket block. I'm running a 400 block bored to 4.155.
They're really sticking you on the camshaft cost too. You can order a small base circle cam from CompCams or Crane for half of what Summit quoted you.
I don't know what the specs are on the combo they've been talking to you about but I'm running a stock diameter base circle hydraulic roller cam ground on 114 centers.
Why they want you to opt for .870, which is really small and 109 centers is a mystery to me. .900 is more common.
Post all the specs they're using so I can get a better handle on this.
Jake
[Modified by JAKE, 9:40 PM 9/26/2002]
Even at .060 you wouldn't be even half way to what you need at 4.125, so you can forget the L98 with that much bore.
There are other choices though, a 400 block or an aftermarket block. I'm running a 400 block bored to 4.155.
They're really sticking you on the camshaft cost too. You can order a small base circle cam from CompCams or Crane for half of what Summit quoted you.
I don't know what the specs are on the combo they've been talking to you about but I'm running a stock diameter base circle hydraulic roller cam ground on 114 centers.
Why they want you to opt for .870, which is really small and 109 centers is a mystery to me. .900 is more common.
Post all the specs they're using so I can get a better handle on this.
Jake
[Modified by JAKE, 9:40 PM 9/26/2002]
Thread Starter
Racer
Joined: Jul 2002
Posts: 447
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From: Malta Europe
Re: L-98 engine block ? (JAKE)
they Dont realy offer much specks for the kit ,the only specks I got is by asking for them !!! But replacing the block is way over my budget for me !!! now that I can`t do the 427ci kit , I am thinking of building a 396 motor by boring the block to 4.030 wich is safe and using a Crank with 3.875 stroke and 5.85 rods and some je pistons what you think !? on the C4 tech forum told me that a 396 is the best for your needs since you are after hp !! If you dont mind please tell me what I need to do for a 396 motor out of my L98 engine and the best cam shafts to use with this set up !? thank you :cheers:
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
Re: L-98 engine block ? (marlon88)
they Dont realy offer much specks for the kit ,the only specks I got is by asking for them !!! But replacing the block is way over my budget for me !!! now that I can`t do the 427ci kit , I am thinking of building a 396 motor by boring the block to 4.030 wich is safe and using a Crank with 3.875 stroke and 5.85 rods and some je pistons what you think !? on the C4 tech forum told me that a 396 is the best for your needs since you are after hp !! If you dont mind please tell me what I need to do for a 396 motor out of my L98 engine and the best cam shafts to use with this set up !? thank you :cheers:
Guys have there preference and there are a lot of differing positions on this point.
3.875 is going to call for either an aftermarket or offset ground crank. I don't know if a 400 crank even can be offset ground that much, if you're starting with 3.750 stroke, which is what the 400 crank has.
400 blocks are bcoming hard to find but they are still out there. A buddy of mine bought one recently for $200.
If you stick with the L98 block, but stuff in a stroker crank, there will be some clearancing required on the oil pan rail area not to mention different pistons.
I'm from the "more cubes the better" school. I suggest you sit down and first decide on how you plan to use the engine and then do a realistic assessment of your budget. Your budget will be the primary controlling factor in all this.
The bigger you go in cubes, the more costly things become because you'll need more specialized parts/machining.
Just my thoughts.
Jake
Melting Slicks
Joined: Sep 2000
Posts: 3,099
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From: PITTSBURGH PA
Cruise-In IV Veteran
Cruise-In V Veteran
Re: L-98 engine block ? (clem zahrobsky)
to marlon 88 i am not disrespecting you but you should think about a professional in your area to either do this swap for you or help you it sounds to me if you take on this project by yourself you are not going to have nothing but trouble and id hate to see you waste a lot of time and money find a professional engine builder in your area first and talk to him before you jump the gun :cheers:
