My daughter finally got the 2.5 taken apart... (Page 1/1)
82-T/A [At Work] DEC 03, 07:42 PM
We still haven't disassembled the bottom end, but she stripped the motor of everything, and removed the cyl head. We were finally able to get a good look at everything, and it's honestly not horrible... it's actually in pretty decent shape for the age of the car, other than being insanely dirty. A couple of things:


First... one of the cyl head bolts in the middle of the cyl head broke. THANKFULLY... it broke with almost an inch of it sticking up out of the engine. I wasn't expecting a bolt to break off of the block... not sure how this happens, but this is a first for me.




I'd normally hit this with some heat, clean it up and spray some PB blaster and then attack it with vice grips and a pole... however, after looking at the cyl walls... I'm just going to let the machine shop mess with it. The cyl walls are actually not that bad, but the engine clearly has some 120k miles on it, and there is a little bit of a ridge where the rings stop. I'd probably hone this myself, but I already have a set of .030 overbore pistons that I bought, so I'll just have them hone and bore the engine block when they take care of the bolt.

I'll probably ask them to balance the rotating assembly also, but NOT assemble it, and then have my daughter re-assemble everything. We haven't taken out the bottom end, but there were no bearing problems, and I'm expecting I should likely just be able to replace with standard sized bearings.


Combustion chambers actually look pretty good... there's obviously some carbon deposits, but none of the valves look burnt.




One thing I did notice though when we were removing the pushrods... the tops of the valves look like they're coming apart. These are the two that are the worst, but some of the others were in varying states like this, a lot of scoring... didn't look like the valves were rotating as they should. Any idea what causes this? It's kind of weird... I've never seen chips break off of a valve stem before...








I'm obviously not going to re-use these, so I'll replace them. I wanted to ask your guys' opinions on two things:


1. What brand / make do you recommend for replacement valves for the Iron Duke (1985 block and head)? Is there any point to going slightly bigger? Anything I want to stay away from? Just looking for some good stock (or possibly better than stock) replacement ones.

2. If I have the cyl head cleaned and magnafluxed... can I seat the valves myself (or have my daughter doing it) by lapping them with the spindle / cup and the paste? Or should I really be looking to get a 3-angle valve job?

3. What piston rings / set do you guys recommend? The most important thing to me is to maintain good oiling... not really so concerned with getting every last bit of compression out of it. The pistons I'll have are .030 overbore. I figured Chrome-Moly rings... but is there anything else?

4. Can I re-use the springs, retainers, and keys? Or should I order a whole new set of OEM springs and keys?


Thanks guys! I really appreciate it!
sleek fiero DEC 04, 12:09 AM
Hi Todd;
The valves are going to be new so get the machine shop to check and or replace the guides. Then grind the seats so they are concentric. Retainers and keepers are ok but springs are cheap and should be replaced. the shop will check head for straight and resurface as necessary. The chipping is from loose rockers bouncing on the valve tip. sleek
sleek fiero DEC 04, 12:11 AM
Hi Todd;
The valves are going to be new so get the machine shop to check and or replace the guides. Then grind the seats so they are concentric. Retainers and keepers are ok but springs are cheap and should be replaced. the shop will check head for straight and resurface as necessary. The chipping is from loose rockers bouncing on the valve tip. sleek
sleek fiero DEC 04, 12:13 AM
something is screwy on this site . At first it wouldn't post and the it double posted ????
Vintage-Nut DEC 04, 10:17 AM
Todd, I concur with sleek fiero;
I pay the machine shop to get my cylinder head(s) disassembled, cleaned, inspected, repaired, resurfaced, grinded and installing new valves; I only mount the cylinder head(s) back on the engine block.

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Original Owner of a Silver '88 GT
Under 'Production Refurbishment' @ 136k Miles