LT-4 383 Rebuild "LOTS of Pictures" by BlackHarleyMan

10 minute(s) of a 70 minute read

LT-4 383 Rebuild "LOTS of Pictures" 

Compliments of BlackHarleyMan @ corvette forum.com

6-6-2008

Well for those that don't know, my high mileage LT4 spun a FEW bearings, and facilitated my motor upgrade much sooner than expected. (http://forums.corvetteforum.com/show....php?t=2037059) I found a great CF member who knew what he was talking about when it came to motor building, and with his help and support ordered all of the components for this project. I finally decided, at the 12th hour to go with AFR Comp Ported 195's after speaking with Ron over at AI, Lloyd Elliot from EPW, and then Tony over at AFR. I determined that for the money that I was going to spend with AI or EPW to rework my stock LT4 castings, I'd just suck it up and go for the gold. So I ordered my heads on May 16th, and they just came in today.

The heads arrived in perfect condition starting with the shipping container and packing.









Heads came with the 8019 Hyd Roller Valve Springs, and guideplates, I upgraded to the 7/16 studs as recommended by Tony.



Here's a shot of the intake port

Here are the 2.080 race and 1.600 street valves

 

A shot of one of the exhaust ports



And finally a shot of the intake ports with the GM# 12367777 gasket mocked up on the head. According to AFR's website, I'll need to go with the GM #12528884 LT4 intake gasket instead. I'll have to look into this one just a tad more.




I'll post pictures of the rotating assembly and the headers in a few. I'll also post components and specs and follow Will as much as I can with this build. I'm also working on the entire suspension and every other component on this car so I'll try to keep things down as much as I can for the guy's living with dial-up. Thanks for all your help in support!

I got in on a CF Group purchase through Merle over at Exotic Muscle and ordered his LT4 long tubes with AIR, ceramic coated extension with high-flow cats and the full four O2 sensor bungs.

Here's the Passenger side header







Coated extensions with high-flow cats







And finally a shot of the extension O2 bungs



Thanks, but there's more, PLENTY More!.......LOL

Eagle 4340 Steel Lightweight Forged Crank (ESP-43533750057LA) 350 Main, 3.750" Stroke, 5.7" Rod, 1pc Seal, Internally Balanced.





Scat Q-Lite H Beam Rods - 6.000"







383 4 Barrel Manley Pistons, 4.030" Bore, 3.750" Stroke, 6.0" Rod, -12cc 10.1:1 Pistons







Victor Reinz Nitroseal Head Gasket .026" Thick, CCO 4.100"





The FAMOUS Cadillac Racing Lifters






Enjoy, more to come

I decided to use my Virgin LT4 intake for this build and Will is going to completely bore it out so if I decide to go with a Mono-blade later on, I won't have to do anything but bolt it up. Here's the 58mm gasket on the LT4 to show the amount of 'meat" that has to be removed for just the 58.



I decided to get a Professional Products 58mm TB for this build, seeing how reasonably priced they are.





After a nice thread on the subject (http://forums.corvetteforum.com/show...php?t=2007050), I went with the masses and pulled the trigger on a Meziere electic HD water pump and Meziere relay kit.







The decision on a Clutch was a long and hard battle, I talked to pretty much everyone on the subject and decided to go with the Spec Clutch setup. After reading TONS on the subject of various types of flywheels, I also decided that a Single Mass Steel FW was best for me and this build. This is the Spec Stage-2+ which is good for 620 ft/lbs of torque, which should be good with headroom for this build. The thing I liked about the Spec setup, is that the entire setup came fully balanced.







And I'll end the night with my last piece for now, which are my Injectors. Got them off of Flea-Bay for a good price, and CF member Jon FICINJECTORS recommeded I have him look at them before using them seeing how they were used, so I took his advice. I dropped them off at his front door while I was in Alanta one weekend, and they were in the mail on the way up to VA before I had even left Atlanta!......Thanks JON!



Head Bolts, Exhaust Bolts, Main and Oil pump bolts are all ARP bolts. I still have to figure out the Oil pan, and the Dampner. The Oil pump was just shipped yesterday, because it is ALWAYS on back order. It's a Milidon MIL-18750, and Will suggested this pump over the Melling due to the Mellings having issues with breaking and the powdered metal construction. Thanks for looking!

The cam is a custom grind that Will has spec'd out, using his own cam grinder that the family business has used forever. I do know that the intake is 544 (or was as of last week), but the exhaust changed from 544 when I was going to have AI port my stock heads to a number that's more like 56X-57X. I'm sure Will can pipe in here and give more clarity on that, but he's planning on making it an enjoyable car instead of a dedicated tire destroyer.

Way cool, I posted that, then went to go look at your sig!......VERY Impressive. I have a very good long time friend that was teaching at MIT after he got his Master's there. I'm currently working on my BS at George Mason in Engineering Management with my area of expertise being in Submarine Sonar related systems.

Will showed me the weights on the back of the steel flywheel and is going to balance the entire assy. He said it was best to keep the weights so if any changes or components needed to be replaced in the future, it's much easier that way. If the motor was being completely internally balanced, then the weights would be ditched and the balancing would be conducted strictly on the crank. Which will not be the case for this motor.

What kind of numbers did you get out of your build with that HotCam and are you still running the HotCam or did you change to something different? Also, what size injectors are you running and who did your tune?

I was looking at the Spec Stage 3+, but I was informed by them that the Stage 3 would not be as street friendly as the 2+ and be more proned to chatter. Given that the 2+ and 3 are only a 70 ft/lb delta in overall torque, I figured I could live with that. I'm glad to know that your Stage 3 is street friendly though, I'll keep that in mind for my 91 High-Po build.