aluminum vs iron block
A 347 with stock crank, $400 Eagle rods, and quality forged pistons with mildly ported 6.0 heads, LS1/LS6 intake, ported stock TB, and properly sized turbo will get you where you want to be. 700hp+
I imagine stock 6.0 heads with a quality valvejob on stock valves would work fine as well. Just upgrade the springs/retainers etc.
I imagine stock 6.0 heads with a quality valvejob on stock valves would work fine as well. Just upgrade the springs/retainers etc.
Originally Posted by 427
We have had problems maintaining ring seal for more than 6 months of street racing/driving with high HP boosted aluminum blocks. You could probably cure some of it with hard block filler on the 3.9 bore blocks. The LS2 block is built stronger in some key area's, but we have not boosted one hard yet.
Kurt
Kurt
11 & 7 Second Clubs
Joined: Oct 2004
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From: Motorhome, Freeways, Truckstops, Pits
Your thinking is getting clearer. Go with your alum block, stock crank, better heads and whatever additional cubes your block will allow.
Originally Posted by FastKat
the more I read, the more I think I'd rather have the lighter block with less cubes.
We would not use filler in a daily driver/racer engine.
Kurt
Kurt
Originally Posted by Lostpatrolman
Is it ok to use block filler on a street engine, or are you talking about a dedicated track engine?
Launching!
Joined: May 2003
Posts: 200
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Having owned a 427 Darton wet sleeve i would totally agree with kurt there is not enough sealing area on the deck for a real boost application. I have used a cast iron block this time with a 4 inch crank and left it at a 402, at present I am running @21 psi and around 1200 flywheel hp.
I have seen a Darton wet sleeve block in a cast iron application completely crack down the length of the main caps @ 1500 hp.
If you are only seeking 700 hp a ls1 ally block will do the job with no problems.
I have seen a Darton wet sleeve block in a cast iron application completely crack down the length of the main caps @ 1500 hp.
If you are only seeking 700 hp a ls1 ally block will do the job with no problems.
Originally Posted by 2001WS6Vert
I was at the TA Nats last weekend and saw Ronnie Duke's Blue vert. He says it makes 1500 (I'll assume fwhp) with a C5R aluminum.
I cracked the #1 sleeve and fractured #3 and #4 in a C5-R block. Nothing is indestructable.
Originally Posted by GTBMad
Having owned a 427 Darton wet sleeve i would totally agree with kurt there is not enough sealing area on the deck for a real boost application...
FWIW, I think Doug over at ECS has been running 22 psi through his F2 SC for quite some time now on his car and I think he has customers that are also boosted pretty high.
I went with an iron block for several reasons. Not only is it bigger bore (more torque) & stronger (to support whatever boost I end up with), but it also doesn't have sleeves to break loose. Since I might run an open road race or two, that was a consideration for me. And you can bore it. So the 75lbs was worth the piece of mind to me. As was the 50lbs for the blower. 
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Verdad Gallardo The 4.125 bore block cuts down on sealing area. That said, you can run as much power as you want with many set-ups. I like the 4 inch bore for the extra surface area it provides to seal the head gasket. When we used C5R block/heads on Dukes engines, the gaskets would leak from cylinder to cylinder within a short amount of time(runs). They would still run great when the gaskets were fresh.
Friday night Mike Brown's CE went 9.10@15X with a LS2 block at 3900 pounds raceweight. This is the hardest we have seen a LS2 block pushed to date. This block is showing great promise for reasonable money.
Kurt
Friday night Mike Brown's CE went 9.10@15X with a LS2 block at 3900 pounds raceweight. This is the hardest we have seen a LS2 block pushed to date. This block is showing great promise for reasonable money.
Kurt
Originally Posted by Wet 1
So how much boost do you and Kurt feel a Darton wet sleeve 427 will reliably take? 15 psi? 18 psi?
FWIW, I think Doug over at ECS has been running 22 psi through his F2 SC for quite some time now on his car and I think he has customers that are also boosted pretty high.
FWIW, I think Doug over at ECS has been running 22 psi through his F2 SC for quite some time now on his car and I think he has customers that are also boosted pretty high.
TECH Resident
Joined: Jun 2004
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Its not an Ls1 4bolt head only problem. The world products blocks and others at 4.125 bore plus have similar problems..
For a highly boosted engine on a budget run a Iron 6.0 block and spend more on the reciprocating assembly...
For a highly boosted engine on a budget run a Iron 6.0 block and spend more on the reciprocating assembly...
TECH Senior Member
Joined: Nov 2001
Posts: 10,341
Likes: 1
Kurt what do you think about the stock rods in a street car boosted application if you plan on keeping rpms below 6500?
ie: 6L iron block, stock crank, stock rods, 8.0:1 forged blower pistons, 15-20#'s boost
I know the cost of a rod upgrade is cheap insurance but I am interested in what you think the limits are with a stock rod.
ie: 6L iron block, stock crank, stock rods, 8.0:1 forged blower pistons, 15-20#'s boost
I know the cost of a rod upgrade is cheap insurance but I am interested in what you think the limits are with a stock rod.
TECH Resident
Joined: Jun 2004
Posts: 840
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With good tuning you will probably be OK.
Compressive stresses like boost or static CR increases are'nt as wicked on a rod as stroke or high RPM use..
I do see some really affordable LS1 rods around and am like ummmmmmmm....
Compressive stresses like boost or static CR increases are'nt as wicked on a rod as stroke or high RPM use..
I do see some really affordable LS1 rods around and am like ummmmmmmm....
We have never tested the limits of the stock rod. If you keep the piston and pin light with 6500 limit on rpm, the stock rod might suprise you. The problem we run into is the aftermarket pistons are set-up for .927 pin/6.125 length.
Kurt
Kurt
Originally Posted by CHRISPY
Kurt what do you think about the stock rods in a street car boosted application if you plan on keeping rpms below 6500?
ie: 6L iron block, stock crank, stock rods, 8.0:1 forged blower pistons, 15-20#'s boost
I know the cost of a rod upgrade is cheap insurance but I am interested in what you think the limits are with a stock rod.
ie: 6L iron block, stock crank, stock rods, 8.0:1 forged blower pistons, 15-20#'s boost
I know the cost of a rod upgrade is cheap insurance but I am interested in what you think the limits are with a stock rod.
