Best block for 427 build
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From: Elmhurst, IL (Chicago Suburb)
Originally Posted by JVetthead
Thanks, but could not find link on sidebar..Got link?
LME, another local builder I did not know about, but found link. Been about 4 yrs since I've built an engine, man alot has been going on since then...
I need big tq. for road race car and alot of romance value (for me,semi oldfart) in a 427 so will probably stick with the 4.125/4.00 setup.
LME, another local builder I did not know about, but found link. Been about 4 yrs since I've built an engine, man alot has been going on since then...
I need big tq. for road race car and alot of romance value (for me,semi oldfart) in a 427 so will probably stick with the 4.125/4.00 setup.
Originally Posted by JVetthead
might be close to pullin the trigger on this..
Any reason NOT to use the LS7 block??
Any reason NOT to use the LS7 block??
Thread Starter
Staging Lane
Joined: May 2007
Posts: 83
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From: San Leon TX
[QUOTE=Beast96Z]Because you are limited to a 4.125" bore and a shorter sleeve. The LS2 Darton case will allow for you to run a longer stroke and have a larger bore if you ever want it. If they are close to the same price, you might as well get the one with better parts.[/QUOTE
Good point..Cant imagine needing to go bigger, BUT we all know how that goes.. Guess its about time to start a top end tread..
But back to one of my original questions..Are there any reliability issues with the dry sleeved blocks? I run all out for 20-30minutes at a time...
Good point..Cant imagine needing to go bigger, BUT we all know how that goes.. Guess its about time to start a top end tread..
But back to one of my original questions..Are there any reliability issues with the dry sleeved blocks? I run all out for 20-30minutes at a time...
TECH Resident
Joined: Aug 2004
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From: Portland Oregon
I am glad that you started this thread because I am looking at all of the same options for road racing. I get a super deal from the chev dealer so I am looking at the LS7 block also, but from what I read here there may be some benefits from a sleeved LS2.
If you stick with 4.125x4.00 the LS7 sounds safe.
Does the LS7 block have all of the oil passages plumbed for a LS1 type wet sump oil pump? Will my LS6 heads and FAST90 bolt on?
If you stick with 4.125x4.00 the LS7 sounds safe.
Does the LS7 block have all of the oil passages plumbed for a LS1 type wet sump oil pump? Will my LS6 heads and FAST90 bolt on?
TECH Resident
Joined: Aug 2004
Posts: 875
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From: Portland Oregon
" .
I'm not planning a 4.125 stroke, but what is the oil problem that I keep hearing about, is that only with strokes over 4.00?
I would not recommend a 4.125 crank in any production block, The sleeve are just not long enough and the oil consumption problem would be horrible."
My first choice would ba a dry sleeved LS2 block using LS7 sleeves. You can get a max bore of 4.190" out of this set-up. Also, since the sleeves are actually longer, you can run more stroke and not have to worry about crappy ring stacks and oil problems
I'm not planning a 4.125 stroke, but what is the oil problem that I keep hearing about, is that only with strokes over 4.00?
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On The Tree
Joined: Jul 2004
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Originally Posted by Bring the Noise
Has anyone tried one of the L92 4.10" stroker 427's that Scoggin Dickeys was suppose to offer (can't find it on there site)...
Can't find the 440's on there either. But I have a hard time finding anything on their site. They need to invest in a "Human Factors Engineer" for their web site.
Thread Starter
Staging Lane
Joined: May 2007
Posts: 83
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From: San Leon TX
Does the LS7 block have all of the oil passages plumbed for a LS1 type wet sump oil pump? Will my LS6 heads and FAST90 bolt on?
Good question..I believe the LS7 is compatable with wet sump as I dont think everybody that has done one does the dry sump allso but... experts please confirm? Same with LS6 heads..bigger valves needed of course but a bolt on, right?..
Good question..I believe the LS7 is compatable with wet sump as I dont think everybody that has done one does the dry sump allso but... experts please confirm? Same with LS6 heads..bigger valves needed of course but a bolt on, right?..
Thread Starter
Staging Lane
Joined: May 2007
Posts: 83
Likes: 0
From: San Leon TX
Originally Posted by racecar
I am glad that you started this thread because I am looking at all of the same options for road racing. I get a super deal from the chev dealer so I am looking at the LS7 block also, but from what I read here there may be some benefits from a sleeved LS2.
If you stick with 4.125x4.00 the LS7 sounds safe.
Does the LS7 block have all of the oil passages plumbed for a LS1 type wet sump oil pump? Will my LS6 heads and FAST90 bolt on?
If you stick with 4.125x4.00 the LS7 sounds safe.
Does the LS7 block have all of the oil passages plumbed for a LS1 type wet sump oil pump? Will my LS6 heads and FAST90 bolt on?
Dont know why my quotes are funky but the point is.. best 4.125x4.000 Thread Starter
Staging Lane
Joined: May 2007
Posts: 83
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From: San Leon TX
Originally Posted by LILS
Which is why, contrary to prior assertion in this thread, Corvette Racing uses 4.180"x3.875"?
Thread Starter
Staging Lane
Joined: May 2007
Posts: 83
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From: San Leon TX
Originally Posted by LILS
You're probably on the right track; but the main point is that "best" is not context free. For road racers, the context usually includes at a minimum both racing rules and economic constraints.
So forgive my misuse of words, I will re-phrase.."Best" for me...
Last edited by JVetthead; May 28, 2007 at 12:32 PM.
In high stress situations, the Darton sleeve is a much better material than the stock LS7 sleeve. Cracking a sleeve with a Darton is unheard of, but not the case with the LS7's. For abusing situations, I'd lean more towards the sleeved LS2.
As for the other questions, the LS7 can be used with wet sump and will accomodate any LS based head. You just need to open the chambers to the correct bore size, as you would do with any motor.
As for the other questions, the LS7 can be used with wet sump and will accomodate any LS based head. You just need to open the chambers to the correct bore size, as you would do with any motor.
Thread Starter
Staging Lane
Joined: May 2007
Posts: 83
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From: San Leon TX
Originally Posted by Beast96Z
In high stress situations, the Darton sleeve is a much better material than the stock LS7 sleeve. Cracking a sleeve with a Darton is unheard of, but not the case with the LS7's. For abusing situations, I'd lean more towards the sleeved LS2.
As for the other questions, the LS7 can be used with wet sump and will accomodate any LS based head. You just need to open the chambers to the correct bore size, as you would do with any motor.
As for the other questions, the LS7 can be used with wet sump and will accomodate any LS based head. You just need to open the chambers to the correct bore size, as you would do with any motor.
I dry sleeve both LS2 and LS7 blocks. I try to keep block cores of each in stock.
The blocks are very similar with the LS7 having doweled steel main caps instead of powdered metal non doweled caps as on the LS2. The caps are not interchangeable between the blocks. The bolt spread is different on the LS7 block.
The Darton dry liner which I did most of the design work on is 5.800" over all length suitable for strokes up to 4.250". Bore size can range from 4.125" to 4.190". So you can choose your stroke for 427" depending on how much you want to spend for a crankshaft. Larger bore = better breathing and shorter stroke = less friction which is why Chevy went with 3.875" stroke and 4.185" bore.
The stock LS7 sleeves will not hold up to racing use. I get several blocks a month in to repair with cracked liners. Most were normally aspirated, not boosted. Some are so badly cracked the only way to save the block is to machine away the stock aluminum wall and install MID wet liners.
Steve
The blocks are very similar with the LS7 having doweled steel main caps instead of powdered metal non doweled caps as on the LS2. The caps are not interchangeable between the blocks. The bolt spread is different on the LS7 block.
The Darton dry liner which I did most of the design work on is 5.800" over all length suitable for strokes up to 4.250". Bore size can range from 4.125" to 4.190". So you can choose your stroke for 427" depending on how much you want to spend for a crankshaft. Larger bore = better breathing and shorter stroke = less friction which is why Chevy went with 3.875" stroke and 4.185" bore.
The stock LS7 sleeves will not hold up to racing use. I get several blocks a month in to repair with cracked liners. Most were normally aspirated, not boosted. Some are so badly cracked the only way to save the block is to machine away the stock aluminum wall and install MID wet liners.
Steve
__________________
Steve Demirjian
Race Engine Development
Oceanside, Ca.
760-630-0450
web: www.raceenginedevelopment.com/
e-mail: race-engine-development@***.net
Steve Demirjian
Race Engine Development
Oceanside, Ca.
760-630-0450
web: www.raceenginedevelopment.com/
e-mail: race-engine-development@***.net
Thread Starter
Staging Lane
Joined: May 2007
Posts: 83
Likes: 0
From: San Leon TX
Steve, We emailed last week about re-sleeve prices..I like the idea of the LS7 route. Thanks for bringing this option to light. Would a 3.875 crank be a custom (pricy) piece?
Could you give me prices for an LS7 block re-sleeved to C6R dimensions, you suppling the block? Also options for a short block built to the same? Would there be much cost difference in a 4.125x4.00 vs the 4.185x3.875 built short blocks?
Thanks,
Joe
Could you give me prices for an LS7 block re-sleeved to C6R dimensions, you suppling the block? Also options for a short block built to the same? Would there be much cost difference in a 4.125x4.00 vs the 4.185x3.875 built short blocks?
Thanks,
Joe
Staging Lane
Joined: Jul 2006
Posts: 53
Likes: 0
The stock LS7 sleeves will not hold up to racing use. I get several blocks a month in to repair with cracked liners. Most were normally aspirated, not boosted. Some are so badly cracked the only way to save the block is to machine away the stock aluminum wall and install MID wet liners.