Prepping Block for 383
Thread Starter
Melting Slicks
Joined: Jan 2004
Posts: 2,672
Likes: 1
From: New Cumberland PA
Prepping Block for 383
I have a couple questions in regards to getting the block ready for the 3.75" crank. I purchased a block that was prepped for a 3.48" crank. I set the crank in the block and installed pistons/rods to check and see where I it would need grinding. There are 2 locations where the rod nuts hit. I just purchased a dremel to grind the affected areas.
What is the spec on the clearance needed? There were a few other nuts that were fairly close to hitting, I would estimate .030.
After the block is ground, can I just take it to the car wash and clean it, dry it, and spray it with something like WD40?
What is the spec on the clearance needed? There were a few other nuts that were fairly close to hitting, I would estimate .030.
After the block is ground, can I just take it to the car wash and clean it, dry it, and spray it with something like WD40?
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
I would say you want a minimum of .050 clearance at all points due to the motor growing as it heats up and moving a little in the upper rpm limits. Yes after grinding wash it very good and clean out all passages. Quickly coat it with a WD 40 or something like that. I then take a clean white paper towel and clean the cylinders with auto trans fluid. This type of fluid is designed to suspend dirt in the fluid. You will be surprised at how much stuff is still the in cylinder walls. Keep doing this until you see the paper towel just stay red form the trans fluid. This will help seat the rings quickly. Try to keep everything as clean as possible.
Race Director
Joined: Sep 2004
Posts: 11,874
Likes: 263
From: Arlington Va Current ride 04 vert, previous vettes: 69 vert, 77 resto mod
have you read any of the magazines articles on build a 383? if not i can see i can dig one up for you they talk about all that stuff....
edit :heres what i found so far....
chevy high performance 5/04 and 6/04
popular hot rodding 10/04 and 11/04
edit :heres what i found so far....
chevy high performance 5/04 and 6/04
popular hot rodding 10/04 and 11/04
Last edited by bobs77vet; Jan 5, 2005 at 11:07 AM.
Tech Contributor
Joined: Aug 1999
Posts: 15,174
Likes: 3,983
From: Connecticut, USA
Gordon good info on the tranny fluid! Learn something new every day!
Ok now do you know a good place to find a cylinder brush? Local places didn't have one, Eastwoods didn't have one?
Gary
Ok now do you know a good place to find a cylinder brush? Local places didn't have one, Eastwoods didn't have one?
Gary
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Originally Posted by gtr1999
Gordon good info on the tranny fluid! Learn something new every day!
Gary
Gary
Melting Slicks
Joined: Dec 2000
Posts: 2,198
Likes: 2
From: Eastern Connecticut
Originally Posted by Gordonm
This was a trick my machinist gave to me. It took about 3 to 4 paper towels per cylinder to get them clean. This was after washing the block. It is amazing the dirt and grit that is left in the cylinder wall grooves that did not come out with washing. It is noticably cleaner after this is done. You can really see the cross hatch in the cylinders.
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
You will also need to grint some of the rod bolt heads to clear the cam unless you are using a rod with cap screws. You can put 2 peices of masking tape (not scotch) on the cam lobe to get the clearence you need. I think there is only 2 bolts heads that need grinding but you will need to balance the assembly so grind one from the other 2 journals to get them back in balance. I used a scale to make sure I got them with a couple grams. I think that as long as you balance the rod weights for each journal you should be fine, some may say you need to get all 8 rods the same weight but unless you are reving 6000+ rpm's I wouldn't think that is necessary. If you are reving 6000+ get some rods with cap screws.
Melting Slicks
Joined: Dec 2000
Posts: 2,198
Likes: 2
From: Eastern Connecticut
Originally Posted by Fevre
You will also need to grint some of the rod bolt heads to clear the cam unless you are using a rod with cap screws. You can put 2 peices of masking tape (not scotch) on the cam lobe to get the clearence you need. I think there is only 2 bolts heads that need grinding but you will need to balance the assembly so grind one from the other 2 journals to get them back in balance. I used a scale to make sure I got them with a couple grams. I think that as long as you balance the rod weights for each journal you should be fine, some may say you need to get all 8 rods the same weight but unless you are reving 6000+ rpm's I wouldn't think that is necessary. If you are reving 6000+ get some rods with cap screws.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Race Director
Joined: Mar 2001
Posts: 11,322
Likes: 1
From: Living in the Hartland
Originally Posted by joe73vette
Do you still have to do that if you use 400 sb bolts? They come with the corners already ground off. I got some from ARP when I built my 400 and didn't even think about it. Thankfully it worked fine, even with a GM cam. Joe
Thread Starter
Melting Slicks
Joined: Jan 2004
Posts: 2,672
Likes: 1
From: New Cumberland PA
Fevre
When I purchased the rotating assembly from the machine shop he knew which rod head bolts to clip so that part is done.
Prior to getting the parts, 9 months ago, I read on a web site what the rod to block clearance should be. However, I cannot find that site and it was not a spec that was from a bonaifide engine builder. I could go with 50 thousandths but I only wanted to take the minimum at the minimum amout of places. Don't get me wrong, I'll do what is nesessary.
When I purchased the rotating assembly from the machine shop he knew which rod head bolts to clip so that part is done.
Prior to getting the parts, 9 months ago, I read on a web site what the rod to block clearance should be. However, I cannot find that site and it was not a spec that was from a bonaifide engine builder. I could go with 50 thousandths but I only wanted to take the minimum at the minimum amout of places. Don't get me wrong, I'll do what is nesessary.