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Heads and Gaskets guidance

 
Old 09-03-2013, 04:36 PM
  #76  
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looking at the plug tips 6 and 7 you can clearly see they are rusting,
this means water is in the cylinder
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Old 09-03-2013, 06:03 PM
  #77  
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I'm friends with a guy who went to UTI (or something like that, a mechanic school) and John henessy school of performance, and his dad is also a mechanic, and I think they'll do the job for $1000 If I buy the parts, so my plan if action is to buy the GCS head gaskets from 928 motor sports, and have them do the job. They aren't porsche experts, but I've seen their work and I trust them, and it's all I can afford as well. I'm also going to pickup the heads once they get them off and take them to a local machine shop to be re-worked, and also have the high compression lines from the transmission rebuilt while the engine is out. My goal is to get the car back to the condition it was in when I purchased it, and refresh what I can from there. I think I'll beable to get it on the road again for about $2000? Then I'm going to save up to drop it off at porsche for a full refresh. Once I get my phlebotomist certification I should be able to do a lot more refresh work, but for now I just want to get it on the road again. Am I just dreaming? Or is that a good path of action?

If it ain't broke, I'll fix it 'til it is
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Old 09-03-2013, 09:10 PM
  #78  
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Buy a Victor Reinz engine gasket HEAD set, Roger should have it
also get a silicone pan gasket and a new Laso waterpump.

link to full gasket set,

http://www.ebay.com/itm/VICTOR-REINZ...ddb24a&vxp=mtr
[url]
here are some E bay links for the parts you need.
NOTE it would be better to buy the head set as it will cost less than piece buying all of the gaskets.
not shown are the 8 exhaust gaskets or the valve stem seals or the rear cam tower gaskets get the silicone versions
and install new motor mounts as well Roger has the Volvo mounts

http://www.ebay.com/itm/Porsche-928-...435b35&vxp=mtr

http://www.ebay.com/itm/Porsche-928-...04f0f3&vxp=mtr

http://www.ebay.com/itm/Porsche-944-...32b252&vxp=mtr

http://www.ebay.com/itm/Porsche-924S...4b31ca&vxp=mtr


http://www.ebay.com/itm/Porsche-924-...24875f&vxp=mtr
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Old 09-04-2013, 12:22 AM
  #79  
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Before buying ANYTHING pull the heads and see what shape the mating surfaces are in. Usually a rotten head gasket comes with pitted heads/block. If the heads are pitted, are they shallow enough that a skimming can remove it?
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Old 09-05-2013, 12:35 AM
  #80  
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MRMerlin, does that gasket set also have all of the other gaskets you linked to, or are the ones you linked to the ones I'll need to buy if I don't buy the full set?
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Old 09-05-2013, 12:54 AM
  #81  
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the first link should have all the gaskets,
it wont have some of the O rings like for the oil pump and a few other things,

NOTE that after you figure out what needs to be fixed then you order the parts
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Old 09-05-2013, 12:20 PM
  #82  
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LazerSquid--

I didn't pick up where you and the car are located. Post that in your header, and add your signature line with year and stuff. From location some may recommend a local 928-savvy mechanic who can help you when it gets to that point. You mention taking it to Porsche, which is generally NOT recommended. All the dealer mechanics who went through 928 training have retired or moved on, so you get the lowest guy on the lowest totem pole doing the work. Dealer repair quotes end being crazy catch-all numbers that are intended to cover their butts through all contingencies, and scare you off at the same time.

You can buy a great CD set of the workshop manuals through Roger at 928srus, one of our sponsors. Good used, rebuilt and new parts come from Mark and Tom at 928 International, and new from Roger. I wouldn't think of diving into the car project without the manuals.

You should invest in a Rennlist membership too. For a very few dollars, you get all this support with no pop-up ads. Build a profile with all your info in it so we don't have to search for what car you are working on or where you live. Membership here and at the Owners' Club gets you perhaps the best return on investment you'll ever see with a 928 (short of driving it...).
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Old 09-05-2013, 04:43 PM
  #83  
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Alright, I just wanted to post another update on what's going on. I remembered one of the guys at our local car club is an incredible mechanic, and I'm pretty good friends with him, and I'm currently negotiating a deal to trade one of my spare engines that he always wanted (a FI 13b rotary) for the labor to have the gaskets and rings replaced, new waterpump and timing belts, and while it's out I'm going to replace the motor mounts and have the high-preasure hoses from the transmission rebuilt, along with re-decking the heads. I'll be paying for the parts, which I figure will come out to about $1k, and he'll do the labor at his shop. Does anybody have any objections to this?

Dr. bob, I already have the workshop manuals for the car, and I already bought the rennlist membership. Also, I'm located in northwest arkansas (XNA area), home of walmart, and the car is an automatic 1984 928s that I acquired from a local redneck (who trashed the poor thing). I'll update my profile with all of that info tonight.
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Old 09-05-2013, 05:26 PM
  #84  
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depending on the block condition rings may not be necessary
NOTE you just dont toss a new set of rings into the block because its open ,
Though It would be a good idea to pull the leaking cylinders pistons out to inspect the rings, if they are stuck or corroded then yes new rings,
NOTE the pistons are specially sized for this block so they must be saved.
NOTE to clean them only use a tooth brush and soaking in simple green,
the dull green coating is chromium and this is so the pistons dont seize in the alusil block
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Old 09-05-2013, 05:32 PM
  #85  
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Oh. I was told that when aluminum blocks over heat, they usually squeeze down on the pistons and warp the rings, if that's not true then I won't replace them
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Old 09-05-2013, 05:56 PM
  #86  
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well you should inspect the rings on the two cylinders that were leaking coolant.
And one of the middle cylinders from the other bank then this will also include checking the rod bearings 2 and 6 are the rods that wear the most
If you do install new rings they have to be sized IE the end gaps checked,
and then you dont do anything to the block except to clean the cylinder walls with acetone then add some oil prior to installing the pistons
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Old 09-05-2013, 06:00 PM
  #87  
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Well I guess the reason I worry about the rings, is because the whole row of cylinders was low on the drivers side. Passenger side all read 145-155, but drivers side were all 100-130, even though only the two in the middle had coolant in them. Could the outer cylinders have low compression just because of the head gasket being blown out in the middle? Sorry if these are dumb questions but I'm used to individual head gaskets (motorcycles) that don't cover more than 1 cylinder each.
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Old 09-05-2013, 06:00 PM
  #88  
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I suppose it would be much cheaper to go ahead and buy the leak down tool and test for it that way. I'll look into buying one tonight after work.
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Old 09-05-2013, 06:17 PM
  #89  
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On second though since you did have a few oveheating episodes,
I wouldnt buy the leakdown tool just replace the rings and refresh the heads
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Old 09-05-2013, 06:28 PM
  #90  
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Don't bother with the leakdown tool, since you'll have it all apart anyway.

Rings "fail" by wearing, by losing spring tension, by breaking. They get stuck in collapsed ring lands in the pistons. Any or all of these will be obvious when you pop the pistons out of the holes. Be sure to mark which bore they came from and which direction they were each facing, and reassemble in the same place and position. You'll test the old rings for tension, inspect them and the bores for coincident wear patterns, know their fit in the pistons before you disassemble them, etc.

The pistons have a special coating that must be maintained, so heed the MrMerlin warning about nothing more aggressive than Simple Green and a toothbrush. The block prep is similarly sensitive. So despite the temptation to just clean things up a bit, you must limit that cleaning to detergent, toothbrush or similar soft material. No Scotch-Brite, no steel wool, no sandpaper, no de-glazing, honing, sandpaper or ridge reamer on any of the bores. Be sure to alert your engine builder to these concerns.

----

A few years ago, a guy in the Philly area decided he could make money breaking and recycling parts from 928's. In the process, he saw that good matched piston sets at other vendors could selll for more than engines, so he took the engines apart and wire-brushed all the pistons to look like new aluminum. In the process he removed the skirt coatings and trashed the ring lands. Made scrap out of what might otherwise have been usable parts.
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