New engine needed! Doh!
Thread Starter
Advanced
Joined: Jul 2004
Posts: 97
Likes: 0
From: St Paul MN
New engine needed! Doh!
Hey guys,
My '74 had been having a wicked backfire, and I thought it was finally fixed, but it came back with a vengeance this weekend. Brought it to my mechanic, who told me that at the very least the cam is worn out, and that the engine needs to come apart to fully diagnose the problem.
I'm too new to cars to do this myself, and I don't feel it's worth it to pay to have a rebuild on this motor, since it doesn't really perform all that well. So that leaves me searching for a new motor.
I was planning on replacing the motor a few years down the road when I had more technical knowledge, but I guess it's gotta happen sooner than that. So what do you guys think? LS1? ZZ4? ZZ383? I'm pretty open to suggestions. Thanks,
- Colin
My '74 had been having a wicked backfire, and I thought it was finally fixed, but it came back with a vengeance this weekend. Brought it to my mechanic, who told me that at the very least the cam is worn out, and that the engine needs to come apart to fully diagnose the problem.
I'm too new to cars to do this myself, and I don't feel it's worth it to pay to have a rebuild on this motor, since it doesn't really perform all that well. So that leaves me searching for a new motor.I was planning on replacing the motor a few years down the road when I had more technical knowledge, but I guess it's gotta happen sooner than that. So what do you guys think? LS1? ZZ4? ZZ383? I'm pretty open to suggestions. Thanks,
- Colin
Team Owner
Joined: Jul 2001
Posts: 61,415
Likes: 478
From: Here to make friends
St. Jude Donor '11, '16-'17
There isn't any reason you can't rebuild your current motor with new internals that will give you the HP you want. With a new crank, it can be a 383. Personally, I'd rather have a local machinist rebuild my motor than go with a crate. That way, if anything goes wrong, you have a local person to go back to.
Racer
Joined: May 2004
Posts: 315
Likes: 0
From: North Richland Hills TX
I agree, don't rebuild something that doesn't perform to the specs that you want it...I have an 80, had my 305 taken out, put in a 350 that outperforms a ZZ4; a guy who builds NASCAR engines did this for me...but I've heard very good things about the ZZ4 crate motor, look into it, or perhaps a 383 stroker motor...
Pro
Joined: Aug 2000
Posts: 640
Likes: 0
From: North Texas
It depends on what you do with the Vette. Just cruise, local shows, long trips, is it a daily driver? Do you want to keep the Vette numbers matching?
If your thinking of a LS1 then cost must not be a problem. You need to factor in what you want from the Vette and how you use it. Personally I think the crate motors are the way to go. Turn key install, warranty, good power, its the best bang for the buck.
If your thinking of a LS1 then cost must not be a problem. You need to factor in what you want from the Vette and how you use it. Personally I think the crate motors are the way to go. Turn key install, warranty, good power, its the best bang for the buck.
Drifting
Joined: Aug 2004
Posts: 1,883
Likes: 124
From: Lubbock TX
I'd get a second opinion - he'd have to take the valve covers off and turn it over to check cam lobes, etc. I'd also want to check the timing chain as a lot of stretch can screw timing up pretty bad. You can drop a cam and new lifters in with a new timing set, new valve cover and intake gaskets for less than $200 in a day. Why go thru all the trouble of pulling an engine that hasn't been fully diagnosed yet? Just my .02
Le Mans Master
Joined: Mar 2002
Posts: 7,456
Likes: 2
From: Coming home from Luckenbach Texas
Isn't this the motor with 217K on it? There's no reason a decent machine shop can't do a rebuild, if that's what you want. It can be built up...to where it'll be better and stronger than new!
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Originally Posted by 74Thrasher
I don't feel it's worth it to pay to have a rebuild on this motor, since it doesn't really perform all that well.
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
Instructor
Joined: Dec 2003
Posts: 129
Likes: 0
From: Rio Medina Texas
If your current engine is toast, and your not savy about rebuilds and want more ponies then a crate motor is a good option. You'll get a big boost in your driver with the GM performance crate motor. If that's not radical enough there a plenty of 383 crate setups. My .02
Race Director
Joined: May 2003
Posts: 11,814
Likes: 9
From: Science Bitch! Mississauga, Ontario
Canadian Events Coordinator
Originally Posted by page62
Isn't this the motor with 217K on it? There's no reason a decent machine shop can't do a rebuild, if that's what you want. It can be built up...to where it'll be better and stronger than new!
REBUILD 
Safety Car
Joined: Oct 2004
Posts: 3,725
Likes: 5
From: Minnesota
Originally Posted by CGGorman
Why rebuild when you can go big?
Ya, I'll bet if you stomp on it you'd get all of about 20 feet until little pieces of shrapnel from all those wonderful u-joints, half shafts, and differential start sticking in you. 
Le Mans Master
Joined: Mar 2004
Posts: 7,493
Likes: 1,502
From: Little Rock AR
Rebuild it. If the bores are worn you should stroke it to 383 and add better heads. The cost for the stroker is not much over the cost of the stock overbore rebuild and the performance increase is well worth the effort.
If the bores are still servicable I would overhaul the bottom end and again put better heads on it.
Either way you get better than brand new performance and the personal satisfaction from a job well done. Match the new cam to the rest of the combo and C/R and you are good to go.
-Mark.
If the bores are still servicable I would overhaul the bottom end and again put better heads on it.
Either way you get better than brand new performance and the personal satisfaction from a job well done. Match the new cam to the rest of the combo and C/R and you are good to go.
-Mark.
Thread Starter
Advanced
Joined: Jul 2004
Posts: 97
Likes: 0
From: St Paul MN
Thanks for all the replies.
Here's the thing: It really is not that strong of a motor in the first place. I would say, from the butt dyno, it doesn't pull much harder than my 265 lb/ft Maxima.
And I don't really know what it the motot is, but it isn't the stock block for sure, and like I said, it's not really that strong. So what could I expect to get out of a rebuild with a new cam, heads, and stroking?
Here's the thing: It really is not that strong of a motor in the first place. I would say, from the butt dyno, it doesn't pull much harder than my 265 lb/ft Maxima.
And I don't really know what it the motot is, but it isn't the stock block for sure, and like I said, it's not really that strong. So what could I expect to get out of a rebuild with a new cam, heads, and stroking?
Le Mans Master
Joined: Aug 2003
Posts: 7,720
Likes: 12
From: Chattanooga TN
Originally Posted by 74Thrasher
So what could I expect to get out of a rebuild with a new cam, heads, and stroking?
