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These are pictures from my 1987 944s after the belt broke. You can see i have two moderate gouges. The machine shop says its salvageable and says they can run a tick off the whole face and should be fine because the marks are within the gasket and don't really effect anything. They said they don't think they can totally remove them. The spark plug seats good with no issues. My question is, should i bother? or do you think its trash? Also, if i had to guess, the deepest part is 1 mill If they ran it down to the marks almost being gone, is that TOOOO much. I used hi def pics so you can see exactly what i am seeing. The overall pictures have the gasket laying in it with and without the plug in for reference to show where the marks are. Im not so worried about the marks around the plug, just the ones up higher. Unless someone says to have them mill a bit there also. I know the valve seat will have to be fixed, but i need to know if the marls will be an issue before moving forward.
Thank you as always.
Last edited by bigmacdave; 05-10-2018 at 07:12 PM.
Have the shop clean and mill the head. Then you can really see how bad it is.
I'm guessing a mill and some elbow grease to sand/file/smooth down the remaining dings will salvage the head.
They said they would shave just a tick off (basically take off the high metal) and fix the valve seat and it should be good. my concern would be the left over knick, but they told me it wouldn't be a issue because it doesn't breach under the gasket. does that sound right? Its only $150, but i didn't want to waste it if its not worth the headache. also, i have seen some people that build back up those spots and then they mill them down to perfect (like new) not sure how much that is.
That head IS salvageable, but in the current 944 economy I don't think it would be worth it. If it were off a Ferrari the question wouldn't even be asked. You might save the head though...In another ten years or so 944 economics may have changed.
If you do run that head, all the knicks and sharp edges should be smoothed out. Otherwise sharp edges are just waiting to get hot and cause detonation.
That head IS salvageable, but in the current 944 economy I don't think it would be worth it. If it were off a Ferrari the question wouldn't even be asked. You might save the head though...In another ten years or so 944 economics may have changed.
Not by a skim pass as the OP suggested.
And without modifying the valve reliefs in the pistons (all 16 of them), there's not enough piston to valve clearance on these engines to take off much and that's if it hasn't ever been milled before.
Is it "savable"...., maybe, if the combustion chamber itself isn't collapsed.
Have you ever looked at the cross section drawing in the manual of the 16V heads....?
One of the seat pockets is deformed in 2 places that without welding and reforming the factory sized seat will never stay in place.
If he goes +1mm seats, he's looking at 8 seats and 8 valves, welding the combustion chamber and milling back to factory then welding the gasket surface too.
If.......,if the head can withstand all the welding etc without cracking.
I have welded corrosion pits and broken tensioner pedestals on these heads before to reuse them.
I have pics of my own work to post here but not on this laptop.
I first thought it was toast but thinking about it there's not much difference between the welding the deep scores and welding corrosion, I say if the machine shop says it' salvageable then go for it, they are the experts
I currently have my 2.5 N/A head at the machine shop while my new crank is getting cross drilled and they told me that three out of eight valves were sealing
less than 60% so they are going to regrind my seats and do a few little things while in there ... point is , i thought it was perfectly ok and i'll be into it for a couple hundred dollars
when all is done.I had no idea that there was any present damage ...
I'd be curious at to how much a qualified shop would charge to rebuild a head that is as damaged as yours versus just getting a good used one and refreshing it ?
It's too bad there isn't anyone in the aftermarket making new heads and blocks. There are probably dozens of choices in small block Chevys, and those don't have the performance potential that these engines do. Damn economics of niche markets...
I say if the machine shop says it' salvageable then go for it, they are the experts
Like the machine shop that lost one of my main bearing caps on a VW GTI block that one time?
OP didn't say, but except for the relatively few specialist shops, the local shops most of us have available to us in the US aren't really experts on the European stuff.
And, they get paid for doing the work either way. How convenient.
Like 951and944S said, seat pockets are deformed and too many issues. Cut bait.
That head is only good for one thing now: to serve as a cautionary tale for others.
Like the machine shop that lost one of my main bearing caps on a VW GTI block that one time?
OP didn't say, but except for the relatively few specialist shops, the local shops most of us have available to us in the US aren't really experts on the European stuff.
And, they get paid for doing the work either way. How convenient.
Like 951and944S said, seat pockets are deformed and too many issues. Cut bait.
That head is only good for one thing now: to serve as a cautionary tale for others.
+1....!
I'm near a big city (Baton Rouge) and I'm acquainted with many repair shops.
Probably 50% of those use a certain engine machine shop and swear by them.
I had a run in once with same said shop while dropping off an alusil block as they were talking me through the cleaning and bore/hone procedure "that we use on these".
I loaded the block up and left.
I had a notorious performance shop regrind seats for a +1mm intake valve, so while they had the head, I sent them titanium retainers to install since they'd be checking seat depth cut/valve stem height.
Installed head, traveled 600 miles to , first race on new head.
Driver reported random misfire but car/driver was still top three.
Sunday main event enduro, DNF, smoke, car running on 2-3 cylinders.
Get it home and tear head off.
They decided it best to not reinstall the hardened steel lower spring cup and just had a knurled soft metal in it's place.
The spring dug into the soft metal and wound the coil while the valve was trying to rotate, closing it's inside diameter enough to bind on the inner spring.
This took the guide seals right off the guide.
Head was a total loss.
It was clear exactly what happened (been running an identical head with factory hardened spring cups for + 2 years since) but when I called them to report that the head catastrophically failed with 3 hours race time, they were at a total loss as to how this could have happened.
What's mysterious here is that OP says "this is my head after timing belt broke".
Well....., this damage happened before the belt broke or else there wouldn't be repetitive contacts between the piston and chamber.
So...., yeah..., to tempest's point, if this were a rare factory LeMans head, sure, it could be saved.
But it's not.
05-10-2018, 05:41 PM
Head re-surface
