LSx small journal rods?
Thread Starter
Teching In
Joined: Feb 2008
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From: Portsmouth, England (but an Aussie)
LSx small journal rods? Hi People,
Planning a land speed 4.8l LSx motor for a class that goes up to 304.9 cubic inches and I would like to get closer to the class limit than the stock 293 ci's. We plan to use custom pistons and aftermarket rods so I'm trying to find out if anyone is doing Honda Journal 1.890" LSx connecting rods?
My thought process at this stage if the small journal rods are available is to offset grind the crankshaft and destroke it by 0.090" and the use 3.905" LS1 pistons which would land it at 304.7 if I can find the correct length connecting rod but the custom piston avenue will help there.
Has anyone got any feedback or suggestions?
Thanks
Steve
Planning a land speed 4.8l LSx motor for a class that goes up to 304.9 cubic inches and I would like to get closer to the class limit than the stock 293 ci's. We plan to use custom pistons and aftermarket rods so I'm trying to find out if anyone is doing Honda Journal 1.890" LSx connecting rods?
My thought process at this stage if the small journal rods are available is to offset grind the crankshaft and destroke it by 0.090" and the use 3.905" LS1 pistons which would land it at 304.7 if I can find the correct length connecting rod but the custom piston avenue will help there.
Has anyone got any feedback or suggestions?
Thanks
Steve
For what you are trying to do, I would look into going farther, use a 4 inch bore and really destroke it. You'd probably have to find a custom crank, but in the long run you'd be better off with better head options and whatnot.
Thread Starter
Teching In
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From: Portsmouth, England (but an Aussie)
Yeah we thought of and looked at that route but the $2.5k plus for a Callies custom LSx crank puts it out of our league. We'd really like to go stock crank, doweled stock block, aftermarket rods and custom pistons which is close to the cost of a custom crank, we'll see.
Thread Starter
Teching In
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From: Portsmouth, England (but an Aussie)
Are you at Speedweek next month as I'm there for a few days to get a better understanding of the realities before we start building?
Cheers
Steve
It is still in the build stage. It is using the 3.820 bore because the 3.8 buick v6 was 3.800 so we have good ring selection. We are using a 6.350 rod with a stock crank and TFS is making the cylinder heads. The customer needs 900hp out of this engine!
Kurt
Kurt
Yikes! Quite the project, what kind of rpm? What size turbo?
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Teching In
Joined: Feb 2008
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From: Portsmouth, England (but an Aussie)
That's very interesting Kurt, a good way of limiting custom parts. Our motor is also going to be a turbo motor for Bonneville, we are both obviously building for a blown D engine class but what car class is it going in? We're going for the blown street roadster class (D/BSTR) but won't be on the salt for a few years yet as it will be a home built car, engine etc. So what class are you building for?
Back to the engine, what sort of boost are you building the motor to take, 20 ish?
If your going to be at Bonneville next month I'd really like to buy you a beer and have a chat if possible?
I think I remember reading somewhere that the early SBC connecting rods can be used in the LSx motors as the bearing was the only carry over part, is this correct?
I understand it's a customer motor and you may not be a liberty to say much but give me what your can ;-)
Cheers
Steve
Back to the engine, what sort of boost are you building the motor to take, 20 ish?
If your going to be at Bonneville next month I'd really like to buy you a beer and have a chat if possible?
I think I remember reading somewhere that the early SBC connecting rods can be used in the LSx motors as the bearing was the only carry over part, is this correct?
I understand it's a customer motor and you may not be a liberty to say much but give me what your can ;-)
Cheers
Steve
Not sure the exact class but its a truck body to meet the rules, so he will not be in your class.
The stock 4 bolt head pattern will be used with better studs, so we will probably see 20psi or less to meet the goals.
No Bonneville for me this year, someday I will go. I have never been, but I have had some hardware run!
SBC rods can be used, the only difference is the offset of around .035-.040 to one side. If your pin boss area on your piston is wide enough it will be fine. If you choose a rod that has the offset in the pin end, you can narrow them to remove the offset.
Kurt
The stock 4 bolt head pattern will be used with better studs, so we will probably see 20psi or less to meet the goals.
No Bonneville for me this year, someday I will go. I have never been, but I have had some hardware run!
SBC rods can be used, the only difference is the offset of around .035-.040 to one side. If your pin boss area on your piston is wide enough it will be fine. If you choose a rod that has the offset in the pin end, you can narrow them to remove the offset.
Kurt
Thread Starter
Teching In
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From: Portsmouth, England (but an Aussie)
Should be an interesting truck with 900hp under the hood!
I understand engines are you business and that your probably very busy but I have a a few more, ok a lot of questions for you if you have the time.
Is the block effectively standard except for the over bore with no other modifications or have you fitted billet caps, doweled the original caps or .........? Any mods to the oiling system? I assume it's still a wet sump?
As far as you pistons go, did you have custom pistons made or have you used aftermarket Buick pistons? What's the compression height of the piston, i'd imagine it's pretty low, something around the 1.035" (assuming a 9.020 desk height) with a large dish? What's you preferred compression ratio with LSx's?
If your prepared to give me any info about the heads, what's your intake runner CC and your valve sizes? Have you gone for Inconel or similar exhaust valve? Have you had the exhaust ports opened out or are they as cast / cnc'd and what's the CC? Are you using anything for valve train stability?
Thanks for the info on the connecting rods, I'll have to do some more research on that one to get that one clear. I noticed Callies do small journal LSx cranks but they don't advertise and e-mail address to ask them who makes the rods to suit.
Do you have an thoughts on my plans, do you know if the 4.8l's can be taken out to 3.905" and take 900 plus hp, 0.126" is a lot?
Just want to check something, are you the dude that built that cool green sleeper Nova that was in HOTROD a while back? Nice one if you did!
Cheers
Steve
I understand engines are you business and that your probably very busy but I have a a few more, ok a lot of questions for you if you have the time.
Is the block effectively standard except for the over bore with no other modifications or have you fitted billet caps, doweled the original caps or .........? Any mods to the oiling system? I assume it's still a wet sump?
As far as you pistons go, did you have custom pistons made or have you used aftermarket Buick pistons? What's the compression height of the piston, i'd imagine it's pretty low, something around the 1.035" (assuming a 9.020 desk height) with a large dish? What's you preferred compression ratio with LSx's?
If your prepared to give me any info about the heads, what's your intake runner CC and your valve sizes? Have you gone for Inconel or similar exhaust valve? Have you had the exhaust ports opened out or are they as cast / cnc'd and what's the CC? Are you using anything for valve train stability?
Thanks for the info on the connecting rods, I'll have to do some more research on that one to get that one clear. I noticed Callies do small journal LSx cranks but they don't advertise and e-mail address to ask them who makes the rods to suit.
Do you have an thoughts on my plans, do you know if the 4.8l's can be taken out to 3.905" and take 900 plus hp, 0.126" is a lot?
Just want to check something, are you the dude that built that cool green sleeper Nova that was in HOTROD a while back? Nice one if you did!
Cheers
Steve
The block has a different maincap, it is stock otherwise. It will be wetsump with a hand made pan.
The piston is a Wiseco custom. The pin height slips my mind, but the piston does not use a ring rail support. The LS series deck height is 9.240 + or -. Compression is subject to many different thoughts, this one will be 8-1 ratio.
The head will be a Trick Flow with a inconel ex valve, the rest is still pending. We are leaning towards a CNC version at this time.
The rocker system will be shaft mount from Jesel, they have proven reliable under extreme use.
Most rods are available in 2 inch pin sizes, it is fairly common.
The block should take a 3.905 with no problem.
I did build a 72 sleeper Nova when I was with W2W, it was a fun car to drive and I'm glad you liked it!
Kurt
The piston is a Wiseco custom. The pin height slips my mind, but the piston does not use a ring rail support. The LS series deck height is 9.240 + or -. Compression is subject to many different thoughts, this one will be 8-1 ratio.
The head will be a Trick Flow with a inconel ex valve, the rest is still pending. We are leaning towards a CNC version at this time.
The rocker system will be shaft mount from Jesel, they have proven reliable under extreme use.
Most rods are available in 2 inch pin sizes, it is fairly common.
The block should take a 3.905 with no problem.
I did build a 72 sleeper Nova when I was with W2W, it was a fun car to drive and I'm glad you liked it!
Kurt
Should be an interesting truck with 900hp under the hood!
I understand engines are you business and that your probably very busy but I have a a few more, ok a lot of questions for you if you have the time.
Is the block effectively standard except for the over bore with no other modifications or have you fitted billet caps, doweled the original caps or .........? Any mods to the oiling system? I assume it's still a wet sump?
As far as you pistons go, did you have custom pistons made or have you used aftermarket Buick pistons? What's the compression height of the piston, i'd imagine it's pretty low, something around the 1.035" (assuming a 9.020 desk height) with a large dish? What's you preferred compression ratio with LSx's?
If your prepared to give me any info about the heads, what's your intake runner CC and your valve sizes? Have you gone for Inconel or similar exhaust valve? Have you had the exhaust ports opened out or are they as cast / cnc'd and what's the CC? Are you using anything for valve train stability?
Thanks for the info on the connecting rods, I'll have to do some more research on that one to get that one clear. I noticed Callies do small journal LSx cranks but they don't advertise and e-mail address to ask them who makes the rods to suit.
Do you have an thoughts on my plans, do you know if the 4.8l's can be taken out to 3.905" and take 900 plus hp, 0.126" is a lot?
Just want to check something, are you the dude that built that cool green sleeper Nova that was in HOTROD a while back? Nice one if you did!
Cheers
Steve
I understand engines are you business and that your probably very busy but I have a a few more, ok a lot of questions for you if you have the time.
Is the block effectively standard except for the over bore with no other modifications or have you fitted billet caps, doweled the original caps or .........? Any mods to the oiling system? I assume it's still a wet sump?
As far as you pistons go, did you have custom pistons made or have you used aftermarket Buick pistons? What's the compression height of the piston, i'd imagine it's pretty low, something around the 1.035" (assuming a 9.020 desk height) with a large dish? What's you preferred compression ratio with LSx's?
If your prepared to give me any info about the heads, what's your intake runner CC and your valve sizes? Have you gone for Inconel or similar exhaust valve? Have you had the exhaust ports opened out or are they as cast / cnc'd and what's the CC? Are you using anything for valve train stability?
Thanks for the info on the connecting rods, I'll have to do some more research on that one to get that one clear. I noticed Callies do small journal LSx cranks but they don't advertise and e-mail address to ask them who makes the rods to suit.
Do you have an thoughts on my plans, do you know if the 4.8l's can be taken out to 3.905" and take 900 plus hp, 0.126" is a lot?
Just want to check something, are you the dude that built that cool green sleeper Nova that was in HOTROD a while back? Nice one if you did!
Cheers
Steve
Thread Starter
Teching In
Joined: Feb 2008
Posts: 15
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From: Portsmouth, England (but an Aussie)
Yeah your nova was well cool, definitely nailed your ultimate sleeper goal!
Thanks for the correction on the deck height, embarrassingly I got my wires seriously crossed there.
I feel I've had my 20 questions now so I'll stop bothering you now as I'd go on forever otherwise but I will keep an eye out for details of the finished motor.
Anyways, thanks for all you answers Kurt, you've been VERY helpful indeed.
Regards
Steve
actually one last question, where do you work now?
Thanks for the correction on the deck height, embarrassingly I got my wires seriously crossed there.
I feel I've had my 20 questions now so I'll stop bothering you now as I'd go on forever otherwise but I will keep an eye out for details of the finished motor.
Anyways, thanks for all you answers Kurt, you've been VERY helpful indeed.
Regards
Steve
actually one last question, where do you work now?
6600 rpm clutch dump of death Administrator
Joined: Dec 2001
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From: Texas
gotzy, We discussed this a few years back on here when aftermarket cranks were hard to come by. I believe in the early days of LSx modifications quite a few folks used small journal SBC rods as well to pick up a few cubes as well.
I believe the folks I am thinking about who did Honda or Olds rods just bought used NASCAR rods, and offset ground a stock crank. The crank should be plenty strong as long as you keep a good filet on it.
The only other issue is just taking the offset of a SBC (.035) per rod vs an LS1 rod. You just need enough pin boss width compared to your pin end width on the rod you are using. The NASCAR rods are an inexpensive way of getting Honda rods.
I believe the folks I am thinking about who did Honda or Olds rods just bought used NASCAR rods, and offset ground a stock crank. The crank should be plenty strong as long as you keep a good filet on it.
The only other issue is just taking the offset of a SBC (.035) per rod vs an LS1 rod. You just need enough pin boss width compared to your pin end width on the rod you are using. The NASCAR rods are an inexpensive way of getting Honda rods.
Thread Starter
Teching In
Joined: Feb 2008
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From: Portsmouth, England (but an Aussie)
Cheers J-Rod,
Yeah I'm planning to run used nascar stuff for the rear suspension and back axle for the roadster which the engine is for. I've also looked at them for a sleeper 1955 265 sbc stroker I'm slowly collecting parts for but bizarely haven't thought about it for this motor, probably cause I've only seen them on ebay.
Do you recall if they were trimming down the offsets to match the LSx pistons or using gen I pistons instead with longer rods? Or was it just custom pistons?
Also found this which helps explain some -
https://ls1tech.com/forums/advanced-engineering-tech/467326-offset-pin-pistons-center-rods.html
Steve
Yeah I'm planning to run used nascar stuff for the rear suspension and back axle for the roadster which the engine is for. I've also looked at them for a sleeper 1955 265 sbc stroker I'm slowly collecting parts for but bizarely haven't thought about it for this motor, probably cause I've only seen them on ebay.
Do you recall if they were trimming down the offsets to match the LSx pistons or using gen I pistons instead with longer rods? Or was it just custom pistons?
Also found this which helps explain some -
https://ls1tech.com/forums/advanced-engineering-tech/467326-offset-pin-pistons-center-rods.html
Steve