92 - 383 Experience?
Drifting
Joined: Oct 2005
Posts: 1,918
Likes: 50
From: Angier nc
Cons are cost and frequent trips to your tire dealer.Also teeth whitening since you now have a permanent grin and want to look your best.
Get a plan for your intended driving and the trans/rear end you have now if you don't want to change them as well.
Good heads cost $$$ but you can stroke it now and still make lots of torque for fun driving.Heads can always be added later.
Exhaust upgrade beneficial but not mandatory.
Get a plan for your intended driving and the trans/rear end you have now if you don't want to change them as well.
Good heads cost $$$ but you can stroke it now and still make lots of torque for fun driving.Heads can always be added later.
Exhaust upgrade beneficial but not mandatory.
Last edited by 96 lt-4; Jun 26, 2011 at 11:48 AM. Reason: spelling
Safety Car
Joined: Apr 2005
Posts: 3,624
Likes: 431
From: Dale City VA
First thing is the computer... or finding someone who can tune the thing. Unless youu build some really mild rehashed engine combination that the mail order guys have a tune on file for, it's getting really hard to find someone with the equipment and expertise to tune an early computer.
Second thing is the Opti Spark. I wouldn't build a high performance LTX without upgrading the timing chain. There is nothing availiable for the early spline drive Opti, while there a few different options for the later pin drive Opti. When I built my 92 we converted it to the 95-97 pin drive Opti. The 92 is a first year car and the wiring harness is different (has a 5 pin connector instead of the 4 pin). You have to re-pin the harness and clip off an unused ground wire.
On regular street tires you won't have any problems at any HP level with the C Beam or the rear end. With drag radials you'll have to be over 500HP and launching really hard to tear that stuff up. With slicks and a dead hook off the line, you can tear it up with the stock engine and a monster clutch.
As for the engine itself.
How much do you want to spend?
How much power or what kind of performance out of the car are you looking for?
Lots of options depending on your money and expectations.
Will
Second thing is the Opti Spark. I wouldn't build a high performance LTX without upgrading the timing chain. There is nothing availiable for the early spline drive Opti, while there a few different options for the later pin drive Opti. When I built my 92 we converted it to the 95-97 pin drive Opti. The 92 is a first year car and the wiring harness is different (has a 5 pin connector instead of the 4 pin). You have to re-pin the harness and clip off an unused ground wire.
On regular street tires you won't have any problems at any HP level with the C Beam or the rear end. With drag radials you'll have to be over 500HP and launching really hard to tear that stuff up. With slicks and a dead hook off the line, you can tear it up with the stock engine and a monster clutch.
As for the engine itself.
How much do you want to spend?
How much power or what kind of performance out of the car are you looking for?
Lots of options depending on your money and expectations.
Will
Thread Starter
Advanced
Joined: Apr 2007
Posts: 59
Likes: 0
From: Port Byron IL
Thanks for the feedback. I already have AFR 180 heads, Crane cam 210-224 duration, BBK 52 mm throttle body, & Exotic Muscle long tube headers. I broke the crank shaft, so I have no option but to replace the bottom end.
With the previous mods, I already had issues trying to tune the car, although I gave it my best shot with TunerProRT and Moates hardware. I would really like to get away from having to burn chips in the future. How difficult was it to change to the 95 computer, and what did it cost?
With the previous mods, I already had issues trying to tune the car, although I gave it my best shot with TunerProRT and Moates hardware. I would really like to get away from having to burn chips in the future. How difficult was it to change to the 95 computer, and what did it cost?
Safety Car
Joined: Apr 2005
Posts: 3,624
Likes: 431
From: Dale City VA
Thanks for the feedback. I already have AFR 180 heads, Crane cam 210-224 duration, BBK 52 mm throttle body, & Exotic Muscle long tube headers. I broke the crank shaft, so I have no option but to replace the bottom end.
With the previous mods, I already had issues trying to tune the car, although I gave it my best shot with TunerProRT and Moates hardware. I would really like to get away from having to burn chips in the future. How difficult was it to change to the 95 computer, and what did it cost?
With the previous mods, I already had issues trying to tune the car, although I gave it my best shot with TunerProRT and Moates hardware. I would really like to get away from having to burn chips in the future. How difficult was it to change to the 95 computer, and what did it cost?
I only changed the Opti and timing cover to the 95 stuff for durability reasons. No way an early spline drive opti and timing chain would stand up to kind of RPM and HP my 92 makes.
Those heads and cam won't support a very strong 383. Since you already have them (if they are salvageable) you can reuse them - but it would idle and drive like stock with more TQ down low and power will drop like a stone after 5500RPM.
Will
Pro
Joined: Aug 2009
Posts: 725
Likes: 4
From: Plano, TX
Thanks for the feedback. I already have AFR 180 heads, Crane cam 210-224 duration, BBK 52 mm throttle body, & Exotic Muscle long tube headers. I broke the crank shaft, so I have no option but to replace the bottom end.
With the previous mods, I already had issues trying to tune the car, although I gave it my best shot with TunerProRT and Moates hardware. I would really like to get away from having to burn chips in the future. How difficult was it to change to the 95 computer, and what did it cost?
With the previous mods, I already had issues trying to tune the car, although I gave it my best shot with TunerProRT and Moates hardware. I would really like to get away from having to burn chips in the future. How difficult was it to change to the 95 computer, and what did it cost?
The 92's are batch fire injection and not sequential. Not as easy to tune out cam surge. But with that small of a cam it should be tunable. I recommend the 383 and keep everything else you already have. There are some killer deals on 383 shortblock and longblocks on ebay. You could sell your heads pretty easy and just by a longblock and drop it in.
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Thread Starter
Advanced
Joined: Apr 2007
Posts: 59
Likes: 0
From: Port Byron IL
With my engine combination, do you guys think I can use the 92 optispark, or should I convert to the 95?
I also have SRP forged pistons for the 350. Will the gains from the 383 be worth the extra $500 to get all new pistons, rods, and crank? Or should I just buy a new crank and rods for the 350?
I also have SRP forged pistons for the 350. Will the gains from the 383 be worth the extra $500 to get all new pistons, rods, and crank? Or should I just buy a new crank and rods for the 350?
Burning Brakes
Joined: May 2009
Posts: 1,014
Likes: 7
From: Ft Wayne IN
Tunning isn't that bad. I had PCMforless do an enitial and it was a little bit rich. All you need is a laptop and the correct cable $60 and download the Datamaster program for free. Take a couple of test runs and save the datalogging to send them back and they will do a finer tune to get you really close. They know from doing so many LT-1 combo's over the years. I would go to a newer OPTI and double row timming chain and the rest of your parts will work fine. I ran a
SCAT 9000 crank and forged rods with SRP forged pistons at 11:1 comp.
52MM TB will work but you will need 30lb. injectors. It's been done over and over so just do some reading research. If you have to buy a crank you might as well buy the stroker. I havn't dynoed mine yet but it is plenty fun for the street and I can run dead kneck even with a new Base model C6. Oh I did change to a 3:07 rear and 9.5" 3000 stall
SCAT 9000 crank and forged rods with SRP forged pistons at 11:1 comp.
52MM TB will work but you will need 30lb. injectors. It's been done over and over so just do some reading research. If you have to buy a crank you might as well buy the stroker. I havn't dynoed mine yet but it is plenty fun for the street and I can run dead kneck even with a new Base model C6. Oh I did change to a 3:07 rear and 9.5" 3000 stall
Safety Car
Joined: Apr 2005
Posts: 3,624
Likes: 431
From: Dale City VA
I'd also say the 5.7 rod is better for your application.
The 5.7 rod has a bit more piston speed on and off TDC which works well in lower RPM engines and some feel it this allows a little more detonation resistance. It also has a better ring stack (compression height) on the piston with the oil ring free of the wrist pin.
There is a good selection of pistons in all price ranges for either rod length. Be careful with the pistons. You don't want to get the SCR too high. With that small cam you could get into trouble very easily. Depending on the seat timing of that cam 11.0 to 1 SCR may be over 9.1DCR and that could be over the edge on a lower RPM pump gas LTX daily driver type engine...
I'd be glad to make some calculations and recomendations with a little additional info.
What combustion chamber are your AFR heads?
What is the advertised duration of your cam?
What are the cams Intake Centerline and Lobe Seperation Angle?
Do you plan to deck the block and what head gasket do you plan to run?
Will
The 5.7 rod has a bit more piston speed on and off TDC which works well in lower RPM engines and some feel it this allows a little more detonation resistance. It also has a better ring stack (compression height) on the piston with the oil ring free of the wrist pin.
There is a good selection of pistons in all price ranges for either rod length. Be careful with the pistons. You don't want to get the SCR too high. With that small cam you could get into trouble very easily. Depending on the seat timing of that cam 11.0 to 1 SCR may be over 9.1DCR and that could be over the edge on a lower RPM pump gas LTX daily driver type engine...
I'd be glad to make some calculations and recomendations with a little additional info.
What combustion chamber are your AFR heads?
What is the advertised duration of your cam?
What are the cams Intake Centerline and Lobe Seperation Angle?
Do you plan to deck the block and what head gasket do you plan to run?
Will
Thread Starter
Advanced
Joined: Apr 2007
Posts: 59
Likes: 0
From: Port Byron IL
Combustion chamber volume of the heads is 55 cc.
Advertised duration of the cam is 272 int./286 exh.
Lobe Separation is 112 degrees.
The block has been deck, but haven't thought much about a head gasket. Maybe use a stock head gasket...would that be around .040?
Thanks again for all of your help and input.
Chris
Advertised duration of the cam is 272 int./286 exh.
Lobe Separation is 112 degrees.
The block has been deck, but haven't thought much about a head gasket. Maybe use a stock head gasket...would that be around .040?
Thanks again for all of your help and input.
Chris
Drifting
Joined: Dec 2007
Posts: 1,647
Likes: 4
From: Argillite KY
I put a well built 383 LT4 in this past Spring. I'm still smiling. Torque is everywhere and dripping off the sides. I put in a triple disc 3200 RPM converter. The transmission went first after an outstanding 2/3 shift at 7000 RPM. I built a new one while the car was still moving and had it ready. This was semi-expected. A weekend later with the bulletproof transmission and some serious playing the D36 rear just exploded. It looked like someone put a grenade in the housing. That happened during the 1-2 shift at around 7000 RPM. Now it's got a built D44 and the whole car is bulletproof.........so far. I'm waiting to wring the half shafts out of it or something else. We'll see.
I guess that I'm not sure about the earlier post that said the stock rear is OK if you don't use slicks. I never did and mine blew up.
I guess that I'm not sure about the earlier post that said the stock rear is OK if you don't use slicks. I never did and mine blew up.
Safety Car
Joined: Apr 2005
Posts: 3,624
Likes: 431
From: Dale City VA
Since the block has been decked already you SHOULD to do the short block mock up beofre you buy head gaskets. You want between .035 and .045 piston to head (quench).
I using .040 and 4.125 bore on the gasket for my calculations.
I am also assuming that your cam has +4 advance built into the ICL as most do which puts your intake closing angle at 64ABDC.
With a 16cc dish you will have 10.82SCR (8.73DCR)
With a 14cc dish you will have 11.08SCR (8.93DCR)
With a 12cc dish you will have 11.34SCR (9.14DCR)
Flat top pistons with a 6cc valve relief will set you at 12.23SCR. That will never run on pump gas with the cam you have (9.84DCR).
SRP has a 16cc dish piston PN139630. For 5.7" rod.
IMO for the money and looking at your other options, SRP is your best bet. You could go cheaper with a KB/ICON hyperutectic or Speed Pro hyperutectic piston but they arn't nearley as good.
Will
I using .040 and 4.125 bore on the gasket for my calculations.
I am also assuming that your cam has +4 advance built into the ICL as most do which puts your intake closing angle at 64ABDC.
With a 16cc dish you will have 10.82SCR (8.73DCR)
With a 14cc dish you will have 11.08SCR (8.93DCR)
With a 12cc dish you will have 11.34SCR (9.14DCR)
Flat top pistons with a 6cc valve relief will set you at 12.23SCR. That will never run on pump gas with the cam you have (9.84DCR).
SRP has a 16cc dish piston PN139630. For 5.7" rod.
IMO for the money and looking at your other options, SRP is your best bet. You could go cheaper with a KB/ICON hyperutectic or Speed Pro hyperutectic piston but they arn't nearley as good.
Will