Alright guys I have a blown head gasket on my ls1 it has around 97k miles now I took it to a mechanic and he told me that if he was to change that gasket(and bolts) I don't have a 100% assurance that it will seal up perfect because of the aluminum block being heated over all these years and advices me to go buy an iron block. Is this at all true or good advice ? is it better for me to grab an iron block for further problems? I need input guys it's my DD and I need it fixed.

If I went with the iron block lq4 how easy would be my swap? of course I would cam it, swap heads and a few other things here and there while the engine is out

Thanks in advance!

 

Sounds like repair shop , money sucking, mechanic bs to me. But I am not that knowledgable. Did you overheat the engine bad enough to warp the head? Is that what he's saying?I have never read nor heard that due to aluminum ,head gasket replacement is iffy.Someone else will chime in and point you in the right direction. Most likely tell you to get another mechanic.

 

Sounds like a bunch of **** to me. I work at a gm dealership and have done numerous aluminum ls engine jobs without any hesitation due to the block material. Unles you overheated the engine I wouldn't worry about just replacing the gasket.

 

That's a load of horse ****. Yes, if the cylinder head gets too hot it can warp, and if the engine itself gets too hot the deck can warp. However the cylinder head will go long before the deck, and if the cylinder head is warped you can just take it to a machine shop and (provided it's not too badly warped) machine it flat again.

 

Thanks for the input guys and that's exactly what I was thinking.
And as far as over hearing it ..it has over heated one time where I had to turn it off but idk if one time may cause it to warp and if the heads are damaged I'm going to buy the 243's my only concern is my block. I'm taking it to the Gm dealership soon and see what they tell me and the repair shop but thank you guys for assuring me it is indeed bullshit because that's what I was thinking from the get go

 

Personally, I wouldn't take it to a dealership. They'll likely charge you a twice as much as what a machine shop could tell you if you pull the heads yourself.

 

Thats a load of bull sh**. The head gasket is there to fill the void between the head and block. If you are really worried about it sealing have a machine shop check your head and machine it to get it totally flat. Even that is only necessary if you over heated your engine severely and warped your head. Aluminum is porous by nature, but much to small for any oil/coolant to come out, unless you have a structural fault in the metal. I would just make sure you buy a quality brand gasket and torque it to the right spec. A quick way to check your engine block and head is get a straight edge metal ruler or something and lay it over it, if you see a noticeable gap, or high/low spot take it to an engine builder/machinist for further investigation(very unlikely).

 

Yes, you will always want to check the head surface as aluminum heads frequently will warp when overheated and need to be surfaced.

A problem with block warpage would be rare, but you can check the deck surface for true with a straight edge and feeler gauge (.003 or something like that).

 

that's my problem, iv heard back and forth from many people it wouldn't be a problem just change the gasket and have the head straightened at a machine shop or swap them and others will say if you spend the money taking them off and then find out they are warped you get them machined and if you find the block warped you're in for some ****. To be honest with you I don't know what caused the gasket to blow in the first place I changed the thermostat, temp sensor, and water pump all to find out I did all that AFTER the gasket was blown so I don't know if I've eliminated the heating cause or have I not. I've been told swap motors it would be cheaper in the end but that's far fetch for a blown gasket imo, and sorry I'm new to all of this i probably sound like a foolish newbie on here but you guys know better than me. I need all the info and opinions I could get.

 

Well what probably happened was the gasket let go, and caused a drop in pressure in the coolant system. Remember that for every psi of pressure the boiling point of water increases by 3 degrees. So if you lose pressure you'll run into overheating problems.

Honestly, I highly doubt it's cheaper to out a replacement engine in. Most ls1s on eBay run like 3-4k. Those that don't are questionable. You could buy a set of 243 heads with springs and valves for far less. I think tsp has a ported set on their website for like 1500?

And again, deck warpage would be an extreme overheat, like steam billowing out of the hood extreme.

Imho I would change the heads myself. They aren't particularly hard to get to on the corvette, and it's a good learning opportunity. Plus noting can beat the satisfaction of fixing your own car

 

Even cheaper I've seen.. And low-mile, stock 243s from guys upgrading are like $450 all day long. Gaskets are $100-$150. I agree on changing yourself if you have the time..really not a big deal as these engines are dead simple.

Stock 243s are a compression bump and flow better so even for the $500-$600 or so would net you a running engine and an extra 30 HP.

 

Personally I would remove the heads, probably can be milled .010" since you didn't really overheat. Won't change compression that it would matter. Make sure the gasket didn't damage the block by burning it and check with a straight edge and not a ruler or that BS. A true straight edge can be purchased from most tool dealers.

While you have the heads removed, change the valve seals and check for wear, and should replace the lifters while you are in there if you are doing both.

 

Until its taken apart and checked ANYTHING is possible. I have seen the deck on aluminum blocks warp bad enough that the block was not useable. So the mechanic is not lying to you. simple enough to check once the head is off.

 

He almost has a point (Op's repair shop) but that is SERIOUSLY over-analyzing like even I've never done before.. And I'm the insane ******* around here that reads into **** and analyzes way to much. (Recovering perfectionist)

There's no 100% sealed, but this guy just sounds really paranoid. it's a headgasket.... Do your best to clean it and make sure everything is straight and true and run the car. if you have a problem that relates back to the HG, then you can worry.