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Tahoe motor rebuild

Got both heads assembled. I ditched the valve seals ,and used orings instead. Also put a .080 thousands shim under each stock spring,intake is around 125 lbs seat ,and exhaust is around 115 lbs . Stock pressure was a little less than 80 lbs. A picture of the 4 door Tahoe . I also got a c clip 14 bolt 6 lug rear for it .
 

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My 6.2 used to pump up the lifters and shut off on a quick rev,and it went away when I changed the springs. Not sure about heaters,not real worried as of now. There is lots of 4 door Tahoes in our area,but they are all gas. Most of the Burbs are gas also. I can take a picture from the side if you never saw one.
 
It was a 350 Vortec that got ruined from leaking intake gaskets. What a surprise.
 
6.2 turbo said:
http://www.thetrucksthttp://www.the...w.thetruckstop.us/forum/images/attach/jpg.gif I'm planning on using 12.9 allen head bolts for mains and heads . Also a picture of my 6.2's oil pump drive. Got all the cyls grooved for orings and got the orings in on one side.
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Maybe we missed it, but where did you get your O-rings? We had a look at the "groover" at Summit but found it was a little pricey. This really interests us, as the majority of deck damage we find is just around the bore and usually just the deck surface and not the heads. We are using the Cometics and ARP's again.

You had mentioned that your gaskets were .042" thick, I take it then that the O-ring is grooved to fit snug to head when bolted down. Did you leave extra depth to insure squish when torquing? Man, we got so many questions, it ain't even funny.....LOL.

This just might be our next mod to these blocks, as it has the potential to resolve some of the boost issues.
 
I used .040 stainless wire. The groove is cut .030 deep,which gives .010 of stick out above the deck. If the copper gasket leaks for me I will use Victor Reinze,and flip the fire rings. I did this on the 6.2. It worked,but I couldn't test it very long ,because the main bearings spun.
 
I had a '97 Tahoe, loved it, if it had a 6.5 in it would have been a keeper.... I would love to swap a '95 tahoe all over, keep it OBD-1. That would be cool.
 
It is a bit confusing. Stock head gaskets have fire rings. Some people remove this on the Cummins and replace it with a 3/16 steel oring ,and cut receiver grooves in the head and block,this would be fire ringing. Also you can oring the head or block or both and use a stock head gasket,but on the 6.5 the stock fire ring is not wide enough,which is why I flipped them on the 6.2.
 
Jeff did a search this morning, with the fire rings, guys are talking 100psi boost. With the O-rings there was talk of up to 70psi boost. Both are well above the current boost level most of us have with the 6.2/6.5L's.

I was not able to tell from the pics,(kinda blind), your groove, is it an increase in bore diameter, or if not, how far out into the deck from edge of bore did you go. I know the fire rings (metal section) on some of the head gaskets is not very large, sometimes as little as .080". Just trying to get my head around all this. Not sure if this is needed or compatible with Cometic's, as whole gasket is stainless.
 
I practiced on an old block,untill I got the oring out far enough ,that it didn't catch the inserted wire on the factory fire ring. I kept this setting for the copper gasket,so I can go back to Victor Rienze if they leak. I tried Cometics and head studs on the 6.2,but they leaked compression into the water. Also I lowered the compression even more,and tried the solicor gaskets,these actually have a solid core,but they blew also. I can measure the oring diameter before I put the heads on the 6.5. I guess I will put silicone or indian head shelac on the copper to help seal the water jackets. I also am planning on using used head bolts. I have quit a few ,so I will use which ever can take the most torque.
 
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I plan on building a DB2 pump,but might use a turned up stock one at first, just to get it running and shifting. I have the timing cover on,and bought a water pump for a 97 with dual stats,but didn't notice the difference from the 95 one,I want to check it out closer. Not sure what for sealer to put on the copper head gaskets,most people say silicone,but I'm leaning towards Indianhead shelac . I also got some liquid thread sealer for the head bolts. I have 10.9 ,11.9 and 12.9 bolts the 12.9 bolts didn't impress me, so I might try the 11.9's , these are used 6.2 bolts .
 
6.2 turbo said:
I plan on building a DB2 pump,but might use a turned up stock one at first, just to get it running and shifting. I have the timing cover on,and bought a water pump for a 97 with dual stats,but didn't notice the difference from the 95 one,I want to check it out closer. Not sure what for sealer to put on the copper head gaskets,most people say silicone,but I'm leaning towards Indianhead shelac . I also got some liquid thread sealer for the head bolts. I have 10.9 ,11.9 and 12.9 bolts the 12.9 bolts didn't impress me, so I might try the 11.9's , these are used 6.2 bolts .
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the engine rebuilder we just got our engine machined at only uses used bolts in the motors they build... they say the new bolts are such low quality that they bust even when they are new... all the bolts are hot tanked and expected before use...
 
China bolts are junk,never tried new head bolts on a 6.5,but did on lots of gas motors,never snapped,but they allways feel softer than used.
 
buddy said:
They use used torque to yield bolts?

If head studs are used so often, what would be the issue with using regular bolts that are not TTY?
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I tried that on the mains 12.9 grade,but imported . These stretched more than stretch bolts,how weird. Also I used 11.9 stock 6.2 bolts for the heads,and 2 were soft,replaced these 2 with 10.9 bolts and they torqued to 135 ft lbs ,same as the 11.9 bolts .
 
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