Planning engine overhaul - what do you think?
Thread Starter
Racer
Joined: Nov 2008
Posts: 469
Likes: 0
From: Tallinn (Estonia)
Planning engine overhaul - what do you think?
Hi,
Since last Summer my Vette began puffing some blue smoke on gear shifts and start ups, especially startups, I thought I should invest in the engine overhaul and change most of the stuff that wears out.
I found this kit in Summit, what do you think? Is it good to replace the pistons, too? http://www.summitracing.com/parts/FEM-MHP126-300/
In addition I'm planning to add new lifters also.
Do you think I might gain some extra power after installing everything in this kit?
I haven't done major engine repair yet myself but I will have an experienced friend to help me if needed.
Since last Summer my Vette began puffing some blue smoke on gear shifts and start ups, especially startups, I thought I should invest in the engine overhaul and change most of the stuff that wears out.
I found this kit in Summit, what do you think? Is it good to replace the pistons, too? http://www.summitracing.com/parts/FEM-MHP126-300/
In addition I'm planning to add new lifters also.
Do you think I might gain some extra power after installing everything in this kit?
I haven't done major engine repair yet myself but I will have an experienced friend to help me if needed.
Instructor
Joined: Jan 2006
Posts: 228
Likes: 1
From: Warwick New York
I would locate the machine shop that you are going to use and talk to them about your plans. Until the block is actually striped cleaned and measured you have no real idea what parts you will need. Ask around and find the most trustworthy machine shop.
Melting Slicks
Joined: Feb 2006
Posts: 3,428
Likes: 5
From: Japan
What he said...don't know what the automotive machine shop business is like in your corner of the globe, but if you're absolutely sure you know of a place that can handle accurately boring/ honing your cylinders to within .0005" of the specified tolerance then the Summit kit would be a good choice because all the parts are there to completely freshen your engine. One thing that you want to be absolutely sure of before you begin is that your cylinders aren't already worn beyond .030" over standard bore (4.000") The last thing that you want to have to deal with from halfway around the world is a box of parts that you can't use. Northern Automotive also sells quality engine kits that you can more specifically tailor to your requirements that INCLUDE cam/lifter sets so you might want to look at them as well...as far as gaining power from the installation of an engine kit that would be more a function of camshaft selection and tuning (carb and ignition) but if everything is done properly you would definitely recover what your engine lost from being old and tired.
Last edited by birdsmith; Feb 6, 2012 at 10:25 PM.
Thread Starter
Racer
Joined: Nov 2008
Posts: 469
Likes: 0
From: Tallinn (Estonia)
Thanks a lot for the info. I will ask my friend about this measurement possibility. About camshaft replacement... Does it mean I should also put on new cylinder heads and all such stuff to actually gain anything and make it work?
Burning Brakes
Joined: Sep 2009
Posts: 1,124
Likes: 140
From: Western New York
Why don't you have your friend help you and replace the valve seals, first. You can do it without pulling the heads, and it most likely will eliminate the smoke at startup and between shifts. Then you can spend your money on something else you were planning to do. That is unless your engine is really tired and truly in need of a rebuild. Good luck.
Duane
Duane
Thread Starter
Racer
Joined: Nov 2008
Posts: 469
Likes: 0
From: Tallinn (Estonia)
Replacing just the stem seals is another thing I was considering. I just thought perhaps I should give it a full overhaul. But there are no other signs of wear for this engine and last time the compression was okay like 2 years ago. Haven't noticed any power drop myself since then. It's an all original engine still with the Q-Jet carb and stuff. I don't know whether I should begin to pump it up for some extra HP or leave it all original...
Melting Slicks
Joined: Feb 2006
Posts: 3,428
Likes: 5
From: Japan
Coming from billa, this is sound advice indeed. Do your 'due diligence' before you go ripping into the engine. Again, to install any engine kit requires quite a bit of very exacting machine work, and all those shiny parts will be worth nothing if you can't get the prep/machine work properly done. Rebuilding an engine isn't that difficult; just a series of about 274 steps that all have to happen EXACTLY right...
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
Drifting
Joined: Jun 2010
Posts: 1,781
Likes: 15
From: Oxford Ohio
All the valve seal suggestions are right on as is the testing. The Compression and a vacuum test. I didn't see your miles, the start up smoke is often the seals. If it's the guides, addressing the heads may be a cure.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
If you want an engine that will make significantly more power, you would do better to build a new engine. Since yours is still working fine, either drive it until it actually needs help (fix valve seals, of course), or pull it and store it (original engine) and drop in a crate engine or one you build up.
If you aren't going to put that new power to regular use [you just want it], leave the engine alone. It seems to be serving you well 'as is'. {Hey! We'd all like to be with Angelina Jolie
...but that ain't going to happen, either.}
If you aren't going to put that new power to regular use [you just want it], leave the engine alone. It seems to be serving you well 'as is'. {Hey! We'd all like to be with Angelina Jolie
...but that ain't going to happen, either.}
Le Mans Master
Joined: Sep 2001
Posts: 7,739
Likes: 630
From: Unreconstructed, South Carolina
assuming you're going to rebuild/service your OE heads (w/ 76cc chambers).
I don't like most ADVERTISED kits because they seldom have the optimal pieces for YOUR individual needs. Many companies that supply machine shops put together kits according to buyers' wishes.
service your heads w/ fresh "Z28" springs.
L48 has dished pistons.
Replace pistons with Sealed Power p/n H618CP (has a small dome with a positive +3.5cc dome volume.
If deck does Not get cut, surfaced aka decked ... use felpro p/n 1094 head gasket.
a thirty over L48 w/ H618CP30 piston & 1094 gasket makes right at 9.8:1 scr. Decent cheap cam& lifter kit like summit K1104.
CF member dmaaero used H618CP in his build several years back.
If deck is cut, use a thicker gasket.
I don't like most ADVERTISED kits because they seldom have the optimal pieces for YOUR individual needs. Many companies that supply machine shops put together kits according to buyers' wishes.
service your heads w/ fresh "Z28" springs.
L48 has dished pistons.
Replace pistons with Sealed Power p/n H618CP (has a small dome with a positive +3.5cc dome volume.
If deck does Not get cut, surfaced aka decked ... use felpro p/n 1094 head gasket.
a thirty over L48 w/ H618CP30 piston & 1094 gasket makes right at 9.8:1 scr. Decent cheap cam& lifter kit like summit K1104.
CF member dmaaero used H618CP in his build several years back.
If deck is cut, use a thicker gasket.