1994 c4 blown head gasket
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Joined: Dec 2017
Posts: 94
Likes: 28
From: portland or
1994 c4 blown head gasket
Hello All,
I own a 1994 corvette LT1 with 112,000 miles with no engine modifications. I'm not the most talented when it comes to engine work so I am going to take to a local mechanic in Tigard Oregon.
I figure if I'm going to have the engine taken apart, I might as well replace things that should get replaced. Also like to add that the car has been sitting for about two years now.
I was hoping to get some input to help determine what is needed. I am thinking budget wise 5k-6K give or take. Here's what I was thinking I needed but looking for direction
* machined heads
* timing chain
* Petris Kit (Petris showing not in stock) do I go with another brand or wait?
* Head bolts
* Replace fluids
* Do I need springs and lifters?
* Do I need a cam? If so, would I need to reprogram the chip or something like that?
* I am also worried about doing too many modifications other than stock with not having the expertise to work on it.
* I am sure this has been talked about on this site, just not sure how to find them or the links
Thank you in advance!
I own a 1994 corvette LT1 with 112,000 miles with no engine modifications. I'm not the most talented when it comes to engine work so I am going to take to a local mechanic in Tigard Oregon.
I figure if I'm going to have the engine taken apart, I might as well replace things that should get replaced. Also like to add that the car has been sitting for about two years now.
I was hoping to get some input to help determine what is needed. I am thinking budget wise 5k-6K give or take. Here's what I was thinking I needed but looking for direction
* machined heads
* timing chain
* Petris Kit (Petris showing not in stock) do I go with another brand or wait?
* Head bolts
* Replace fluids
* Do I need springs and lifters?
* Do I need a cam? If so, would I need to reprogram the chip or something like that?
* I am also worried about doing too many modifications other than stock with not having the expertise to work on it.
* I am sure this has been talked about on this site, just not sure how to find them or the links
Thank you in advance!
Cruising
Joined: Feb 2024
Posts: 12
Likes: 1
From: Phoenix, AZ
The heads, chain, bolts, fluids are a must really.
The Petris, or equivalent is a really good idea as well
You probably don't need springs/lifters/cam unless the gasket failed quite badly, due to high RPM lift, if it's a more "regular failure" you're probably okay leaving these be, but with that said none of it would hurt anything but your wallet
The Petris, or equivalent is a really good idea as well
You probably don't need springs/lifters/cam unless the gasket failed quite badly, due to high RPM lift, if it's a more "regular failure" you're probably okay leaving these be, but with that said none of it would hurt anything but your wallet
Safety Car
Joined: Sep 2001
Posts: 4,157
Likes: 554
From: Glenbeulah Wi
I would skip the chain, 112,000 miles is not that much should be able to go well into the 250,000 mile range on a stock chain. (My opinion) (Much more work once you decide to replace the chain)
Safety Car
Joined: Jun 2010
Posts: 4,564
Likes: 1,676
I would recommend staying stock rebuild unless these guys have specific knowledge on tuning the 94-95 Corvette PCM.
Ideally, with the head gasket, you are doing both, and all the front seals and the oil pan as well. If you were doing this at home I would suggest a engine bay cleanse, but paying a shop to do it is ridiculous.
Ideally, with the head gasket, you are doing both, and all the front seals and the oil pan as well. If you were doing this at home I would suggest a engine bay cleanse, but paying a shop to do it is ridiculous.
Drifting
Joined: Jan 2021
Posts: 1,314
Likes: 384
From: Northern California
I agree on springs / lifters / cam not being required at this point, as long as everything is clean and you've had no prior problems with the valvetrain.
I would do the timing chain just because you're going to have so much off the motor already that a new chain and sprockets is not much more work; you can replace the oil pan gasket with the blue silicone FelPro one-piece and then you have fewer leaks since you'll also be resealing the top of the motor anyway.
I do highly suggest you have them replace the valve guide seals with the FelPro kits for intake/exhaust seals, or just use the silicone intake seals on both intake/exhaust, because at this age they will almost certainly be in need of replacement anyway as they are probably gone.
I would do the timing chain just because you're going to have so much off the motor already that a new chain and sprockets is not much more work; you can replace the oil pan gasket with the blue silicone FelPro one-piece and then you have fewer leaks since you'll also be resealing the top of the motor anyway.
I do highly suggest you have them replace the valve guide seals with the FelPro kits for intake/exhaust seals, or just use the silicone intake seals on both intake/exhaust, because at this age they will almost certainly be in need of replacement anyway as they are probably gone.
Burning Brakes
Joined: Jun 2022
Posts: 845
Likes: 212
From: Florida
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Racer
Joined: Oct 2012
Posts: 280
Likes: 82
From: Indiana
I wouldn't spend the money to have the old heads machined, new seals, valves, springs, etc. I would consider Trick Flow, or AFR cylinder heads. You can order them complete and will cost about 50 percent more than having your old heads reworked, plus the aftermarket will flow more CFM than the stock heads.
Melting Slicks
Joined: Mar 2002
Posts: 2,878
Likes: 764
From: Sligo PA
You know for $3k you can get a new LT1 crate motor right? Has a three year warranty.
https://shop.powertrainproducts.net/...swnIhDSMd7BF9U
https://shop.powertrainproducts.net/...swnIhDSMd7BF9U
Safety Car
Joined: Mar 2017
Posts: 4,206
Likes: 1,325
From: LeClaire Iowa
You know for $3k you can get a new LT1 crate motor right? Has a three year warranty.
https://shop.powertrainproducts.net/...swnIhDSMd7BF9U
https://shop.powertrainproducts.net/...swnIhDSMd7BF9U
Melting Slicks
Joined: Mar 2002
Posts: 2,878
Likes: 764
From: Sligo PA
They tack on another $500 for a core charge. That's why I said $3k. That and I'm sure there is some freight cost involved. But still not a bad deal at all for a stock 4 bolt LT1.
They seem to have a fairly good reputation online but I've never delt with them personally.
They seem to have a fairly good reputation online but I've never delt with them personally.
Pro
Joined: Feb 2006
Posts: 671
Likes: 10
2021 C4 of the Year - Unmodified Finalist
JM2cW based on my experience, replaced head gaskets twice...buy the absolute best quality race grade head gaskets you can find. This is not the place for "off the shelf" complete gasket parts.
Safety Car
Joined: Mar 2017
Posts: 4,206
Likes: 1,325
From: LeClaire Iowa
Since I don't know phat87 what do you believe is the best quality head gasket made? I don't mean to start an oil thread. Dan
Instructor
Joined: Jan 2004
Posts: 169
Likes: 4
From: I celebrate their entire catalog
Something to think about: since you may be pulling the engine, the transmission will have to come out. If you have an automatic, now would be a good time to have it rebuilt. You could take it to an independent trans expert and have it done (plus a new converter), for $1200 or so.
My '95 auto started slipping at then quickly failed (no 3rd or 4th gear), at 120,000 miles.
My '95 auto started slipping at then quickly failed (no 3rd or 4th gear), at 120,000 miles.
Melting Slicks
Joined: Mar 2002
Posts: 2,878
Likes: 764
From: Sligo PA
Something to think about: since you may be pulling the engine, the transmission will have to come out. If you have an automatic, now would be a good time to have it rebuilt. You could take it to an independent trans expert and have it done (plus a new converter), for $1200 or so.
My '95 auto started slipping at then quickly failed (no 3rd or 4th gear), at 120,000 miles.
My '95 auto started slipping at then quickly failed (no 3rd or 4th gear), at 120,000 miles.
That and rebuilding a transmission just because it's out of the car is a bit excessive. Running a trans until failure and then rebuilding is how you guarantee you're getting the most value. I wouldn't pay someone to rebuild it just because it's out of the car.
Melting Slicks
Joined: Mar 2002
Posts: 2,878
Likes: 764
From: Sligo PA
My opinion is MLS style head gaskets are a lot better. Avoid the racing stuff like copper gaskets. MLS aren't super expensive anymore and they do a great job. I spray them with copper spray adhesive meant for head gaskets and I've never had one leak. The last time I got a set I think they were right around $100 a set. Avoid FelPro. ACDelco has very good MLS head gaskets. Also Manley brand are pretty good. Take a look at Summit Racing. They always seem to have them in stock at a good price.