LT1 383 Build
Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
LT1 383 Build
This engine is for my 1995 Impala SS, but I thought it'd be of interest to the C4 community since we share a common engine (mostly 
)
Power Target
Specs
I'm (finally) starting the shortblock assembly this weekend and I'll start posting pictures and parts lists!
)Power Target
- 400 FWHP @ 5700 RPM
- 400+FWTQ @ 2500 - 4500 RPM
Specs
- 1995 LT1 (2-bolt mains)
- Eagle 3.75 stroke cast crank
- SCAT 5.7" floating pin I-beam rods
- SRP +.030 forged pistons; -16 dome for 11.2:1 with 54cc heads. Zero deck w/FelPro gasket for .039 quench
- Stock aluminum LT1 heads with mild porting
- GM HOTCAM Kit (cam, springs and rockers)
- Stock intake
- 52mm TB
I'm (finally) starting the shortblock assembly this weekend and I'll start posting pictures and parts lists!
Safety Car
Joined: May 2002
Posts: 4,659
Likes: 82
From: Toronto ontario
Cool keep us posted ! My .02 would be to open up the main and rod bearings a bit more than stock. The stock clearances are on the tight side which results in a lot of bearing failures when the LT1 is modified.
Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Agreed on the rods - we opened up the rod clearances to .025 from the spec of .014 - .018. I'm not convinced that the main bearing clearance is a factor, so those are at the high limit.
Team Owner
Joined: Mar 2001
Posts: 30,856
Likes: 293
From: Boston, Dallas, Detroit, SoCal, back to Boston MA
It's not so much the powered metal rods, it the stock bolts that are junk.
You might find the HotCam a little too mild for a 383. it's actually kinda mild for a 350.
You might find the HotCam a little too mild for a 383. it's actually kinda mild for a 350.
Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
With the stock heads and HOTCAM, I think the numbers are right in there. 450HP would be within reach with better heads like AFRs.
Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
This wasn't a max-performance build as it's a daily driver - definitely agree that there were stronger cam choices available.
Race Director
Joined: Nov 2000
Posts: 17,103
Likes: 39
From: stop the fun suckers
I think it will be tough getting 400 fwhp out of that combination unless you have a full after market exhaust and headers.. The hotcam is too small for a stroker.. mine idles like a stationwagon.. see sig for my mods and dyno results.. (granted this is on the dyno known as "the heartbreaker").
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Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
I think it will be tough getting 400 fwhp out of that combination unless you have a full after market exhaust and headers.. The hotcam is too small for a stroker.. mine idles like a stationwagon.. see sig for my mods and dyno results.. (granted this is on the dyno known as "the heartbreaker").
Again, not a max performance build - I drive this thing every day.
Safety Car
Joined: Dec 2002
Posts: 3,655
Likes: 24
From: Charleston SC
Many LT1 HC 350's are above 400FWHP and not far off on TQ with ported stock heads, take a look at Nathens combo for a refernce, just one example. The HC is a mild Cam for a 383 but should be a great daily driver. Guess we will see but I would expect 360-370 RWHP/RWTQ out of that combo with a good tune. Just a note if I remember correctly those pistons with a 4.030 bore and 3.75 stroke are closer to 10.7:1 with the stock heads and stock gaskets.
Last edited by FD2BLK; Oct 11, 2007 at 12:17 PM.
Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
Many LT1 HC 350's are above 400FWHP and not far off on TQ with ported stock heads, take a look at Nathens combo for a refernce, just one example. The HC is a mild Cam for a 383 but should be a great daily driver. Guess we will see but I would expect 360-370 RWHP/RWTQ out of that combo with a good tune. Just a note if I remember correctly those pistons with a 4.030 bore and 3.75 stroke are closer to 10.7:1 with the stock heads and stock gaskets.
The engine is zero-decked and I'm using the FelPro .039 compressed gasket. The aluminum heads are 54cc and I took a mild cut on the head, so I should be right around 11:1
Team Owner
Joined: Mar 2001
Posts: 30,856
Likes: 293
From: Boston, Dallas, Detroit, SoCal, back to Boston MA
Not sure about the rod comment - I haven't heard of any PM rod failures, and GMPP sells them as the new "pink" rod. The factory clearances are definitely tight, though.
This wasn't a max-performance build as it's a daily driver - definitely agree that there were stronger cam choices available.
This wasn't a max-performance build as it's a daily driver - definitely agree that there were stronger cam choices available.
Thread Starter
Le Mans Master
Joined: Jun 2004
Posts: 6,231
Likes: 65
From: Seattle WA
St. Jude Donor '14
I'm using a Melling 10552 high pressure, 10% increase in volume pump with a 3/4" pickup with the stock pan and windage tray (1" longer ARP studs to clear the stroker).
Le Mans Master
Joined: Feb 2000
Posts: 9,715
Likes: 27
From: Kempner Texas
I agree.
Jake
Last edited by JAKE; Oct 11, 2007 at 02:22 PM.
