Valve seat recession - 504 engine

Ray Bell

Ray Bell

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Fellow Frogger
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Jun 10, 2001
Messages
9,170
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Burpengary and Murrumburrah, Qld and NSW
When I fitted the TI head to my wagon a year ago, I had the head serviced, fitted later model valves etc.

After just 10,000km or so I found the tappet gap on one cylinder was closing up, and I had to keep on adjusting it for the next 50,000km until it was apparent it was rapidly worsening... I did up another head and fitted it last week.

The seat in the old head had eroded away by about 2.5mm, and the valve was unmarked.

Any clues?
 
Ray that's interesting to read about. What fuel do you use in your 504? I don't know much about the 504 engines, but is the TI head supposed to have hardened valve seats?

We run our 504 on PULP (usually Optimax) with 1 tube of valvemaster per tank. I know it certainly runs alot better than it did on LRP. We've been running it on PULP since not long after LRP came out - about 1.5 to 2 years or so?

Derek.
 
Ray,
The valves in these motors didn't change from 1965 to the present. Hardened exhaust seats were fitted in 1981 and this is what you need to do. Any head reconditioning workshop can do this without problems, should cost a couple of hundred.
Regards, Graham Wallis
 
Usually just one valve with wear indicates the genuine seat has been replaced with a material not as hard as original.Also bear in mind one speck of dust is enough to hammer the crap out of a seat.Check your air filter.
 
The 1982 GR has got the hardened inserts,so no problem.
I have heard of many cases of recession with the pre 1981 heads, particulary on gas.
LRP is not good enough for motorsport, a friend mine had valve seat recession on his 404 rally car recently.
Apart from that I never had the slightest problem with the way LRP performed in either my 2 litre 404 or my odd fire V6.

Graham Wallis
 
It gets worse!

The replacement head has lost about 15 thou out of all four exhaust seats in the first 1700km!

I have been running straight LRP. I've put some auto trans fluid in it till I get my Doring tin canister on Wednesday.
 
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