I don't know your Year, but I've posted how galvanic corrosion killed the head gaskets (almost always at #7) on the aluminum 113's with enough field complaints, warranty claims and a couple of lawsuits that GM redesigned the heads (only they didn't make it into production until the '91). They blamed the cause on leaking intakes, which seems to be why you pulled it apart. These problems usually manifast by 50,000 miles, and the white at #7 is somewhat typical of the galvanic corrosion seen when there is a problem. So if these are your heads I'd go ahead and do a leakdown test. Modifications won't do you much good without a solid platform.

PS - drain the block by pulling the oil cooler hose at the filter and knock sensor. I'd get the radiator rodded out - flush the heater core with a garden hose.

 

SunCr, interesting info. I also saw your posting on another thread about the head gaskets. All this data is giving me reason for concern, I don't want to reassemble all this from the heads up only to have issues in 5-10K miles. I think this information on the rationale behind the failures along with my low coolant issue I had combined with the evidence of moisture in the motor are leading me to pull the heads. I can get the basic head work done and start fresh!

It looks like head gasket selection is also critical, I see that it appears that the 1003 Fel-Pro is preferred.

I guess this job will continue....................

 

I replaced my heads with the redesigned 113's and used stock head gaskets. Since GM's solution was to counterbore the front and rear intake bolt holes for intake gasket retainers, you might have your shop do that, then use the '91 intake gaskets. They're a heck of a lot easier to work with and the retainers keep them from sliding into the valley when you lay in the manifold. If you go this route, pick up the gaskets first so the shop can size up the counterbore. The '91 Vette gaskets - with the coolant restrictors at the rear - are a little difficult to find these days as they were only used on the '91 Vette. However the F-Body intake, with the retainers and without the restrictors are plentiful and work just as well. To me, the problems always happen at #7 because those restrictors keep the nasty stuff back there longer and once you've got a crappy mix, it just eats up the head gasket. I have no way to prove it, but it's the best I can come up with given all the failures that have been posted around here (and that goes back 9 years when I found this Forum looking for similar).

 

I purchased a felpro gasket set (felpro ms 93318 intake manifold set 45738) for my 88 and it had the coolant restrictors in the rear.... regardless of whether or not these were the correct gaskets, they are 100% not hard to find

 

I already have my replacement intake gaskets, I can't remember the number I'll have to check what I've got.

What will an intake gasket retainer look like? I assume it would be a small dowel like pin to secure the gasket? Sounds like yet another cost from the machine shop.

 

The retainer is simply a round metal protrusion crimped to the bottom of the front and rear intake mount holes which then sits in the counterbore that's drilled into the heads. The Plenum gaskets have similar, only they use plastic nipples. Using them, the alignment is perfect and if you have both (those with and without them) you can see that they provide a perfect alignment for the gasket that isn't there with the original design (or even if it is there, you don't know if it's going to stay when you plop the manifold down. That's why GM added it - per their Service Bulletin, gasket misalignment led to leaks and when you get 2 dissimilar metals together in a wet environment; well, you know what happens - they admitted as much and came up with this solution.

As I said, they're unique to the '91 Vette if you want the restrictors, so make sure you specify that Year. Otherwise, the F Body ('91) works as does anything for the current ZZ4 which uses these heads - they just don't have the restrictors, but they do have the retainers. I bought an extra set when I did mine and I went through 3 Dealers before I found them. And yes, you can use the fairly common, non retainer gaskets, but if you got what GM feels solves the problem, why not take advantage of it? The only other thing is that the Service Bulletin specified longer intake bolts for the front and rear mounts, but my Dealer told me he/she couldn't find them and the part # for these parts (it's in the Bulletin) popped up the original length bolts. And some of the '91 owners who have R & R'd the manifold have found the longer bolts - some haven't. The ZZ4, the last time I asked, used the same length for all the intake bolts so I'm guessing the clamp is the same as long as you use the correct torque - I know it's working on mine.

 

I would not do the head gaskets unless they caused a problem. I would take a shop vac and clean up the intake ports real good, then stuff paper towels in them until assembly time.

 

I'm sure they are for your Year - design wasn't changed until '91 and that's a pretty small number considering the L98 was dropped after that Year. The one size fits all philosphy works just fine for the aftermarket's bottom line and the idosynchracies of OEM engineering rarely makes it to the generic parts we buy. Sometimes it's just as good, maybe even better without something that was there from the Factory - sometimes it's pure crap (like body parts - though after State Farm took it in the rear for insisting on 3rd world country imitations, that market pretty much went away). Anyway, anyone who wants to use this design change is going to be at the mercy of GM and their suppliers. I've never seen a Felpro or any other kit include it - even for current production 113's - but don't worry, your '88 doesn't have it and won't unless you trade/engineer up.

 

my 90 had the coolant restrictor gaskets and the felpro's I bought for it did too. Heres the felpro kit I bought, I got it from summit online. Not sure if your L-98 has a coolant hose on the back of the intake on the passenger side by the distributor like mine though.

 

Not sure, I have a emissions type line that loops over the VC down to the exhaust area and a smaller 1/4or 3/8 line to a fitting right in front of the distributor, maybe that is coolant, I was thinking by looking at it maybe it was vacuum. I'll have to double check.

 

 

OK varied thoughts on doing the head gaskets.

Would it make sense at this point with the intake already off that I at least do a compression test to see what I have. I'll have to do this cranking it by hand as the engine is half assembled but I guess I can still get a decent set of number that way.

My thought is I'd like to do this build once. I really don't want to tear it down in another 2 years and go farther than I have this time, but I'm not looking to build a beast and if the bottom end is OK then no need to go further. Cost of the head gaskets isn't an issue but the heads will go to a machine shop if they come off and that will be at least $250 or more.

 

why would it cost 250.00 to do the heads? If it showed no signs of puffing blue smoke and ran nice just have the heads surfaced (but not with a belt surfacer)and new intake valve seals put on .... Thats all I did to my L-98 heads and now my motor is fine, for that work it costed me 130.00.

as for removing front accesories all you remove is smog pump, a/c compressor, alternator. then you simply remove like 4 bolts and slide the a/c compressor bracket and alternator braket forward to get the heads off. at this point you are about 3 hours of work away from having head gaskets done verses taking all that stuff apart again just to do them anyways if they are bad.

doing them now just seems the time to do it, that and given the history of head gasket issues on this engine at least you have peace of mind.

 

JeffP, your right I can probably get by with a cheaper route on the heads but like you said once they are off it is the time to get them right. I agree that seals would get put on and I'm figuring maybe a valve or two might need work. Also figure I might need some valve guide work if it questionable. If I pull the heads I'd like to do this build with the idea that I don't crack it open for a very long time.

Also think I might have new springs installed to prepare for 1.6 rollers, I figure doing all this work I might as well get a little HP boost for fun.

So that is where I get the increased cost. But you right I could if thing check out clean get by with less.

 

Well, tonight I spent about an hour and got the air pump, A/C, alternator and the associated brackets off the front of the engine. Now I think I've got a clear shot at the heads starting with the exhaust manifolds.

Man 20 years of gunk in the crevices of those brackets!

One question I've got for those that look at the photos of the valley on this motor, When I pull the heads I'll have the push rods out. Now they have some gunk buildup and some a light bit of rust for some reason. The question is how to clean these up for re-assembly? Can I use something like a kitchen scrub pad and some degreaser to clean them, steel wool, other? I could even just replace with standard OEM new equipment but I don't think that is needed.

Ideas welcome.

 

 

brake cleaner works pretty good ..... Glad you have decided to do the head gaskets, make sure you at least have the heads checked for warpage if some is there have them cut, throw some new intake valve stem seals on (pretty much mandatory since the intake valves have to be removed anyways to surface these heads) and make sure if they do need surfacing have them done at a place with a correct machine for it and not one of those places that use a belt sander to do it. here is my L-98 after 3 hours of pressure on its cooling system after doing the heads and using felpro's

 

I'm planning to have the heads looks at by a good shop in the area, I'll be checking to level the heads, and check the guides, maybe bump the springs to LT4 springs for 1.6 rockers, and finish with seals, that is probably the plan.

The pressure test shown above looks good.

Any thoughts on the push rod maintenance?

 

only thing I did to mine was make sure the oil passage in them was clear and wiped them off and put them back in.

 

OK, heads are off now, you can see pics in the first post. I thought I had all the coolant out but the passenger side still had coolant, a littel got into the last cyclinder but I soaked it up immediately. I had removed the hoses on the oil cooler and thought that it would empty the block........ I guess not!

Now I have much cleaning and painting while the head get work.

Can anyone comment on the best way to clean the head gaskets off the block and still manage to keep the cylinders clean of crud? Also, should I treat the cylinder walls with any type of protection or lube while it is open to the elements, it will be open for at least 7-10 days!