My car burns oil at idle but not at high rpm or during operation. I did a compression test - pressures between 117psi and 120psi. I then did a pressure test with a bit of oil in the chamber and the pressures remained the same, so I concluded that the valve seals are by passing. I can change the valve seals, was considering changing the seals with the head on, by putting pressure in the chamber.
Is there other parts that should be changed around the same time? I am not getting and ticking sounds from the head so I think the tappets are ok. Should I replace the guides and the keepers as well.
I was considering new cams (Marks 274FI or 284V) for a little extra power. If I do is there anything else to consider while I am in there??
Replacing Valve Seals
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azruss
- Posts: 3659
- Joined: Sun May 30, 2010 12:24 pm
- Your car is a: 80 Fiat 2000 FI
Re: Replacing Valve Seals
spiders dont have tappets. (DOHC). might want to replace the valve guides while you are in there.
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manoa matt
- Posts: 3442
- Joined: Thu Oct 26, 2006 4:28 pm
- Your car is a: 1978 Fiat 124 Spider 1800
- Location: Honolulu, Hawaii
Re: Replacing Valve Seals
Fiat TC's have tappets, its a "flat tappet" head. The valve adjusting shims and shim buckets are the tappets. It does not have rocker arms.
If you are considering cams, you will want to check the spring pressures and how well the valves seal to the valve seats. It's kind of a "while your at it" situation that can add costs up quickly, and will necessitate removal of the head. At a minimum I'd remove the head and take it to a good shop who has done some fiat heads in the recent past. Have them clean it, check for cracks, check the spring pressures, valve to valve guide clearances which will determine if you need new valve guides, and lap the valves to ensure they seal. Those services should run in the $250-$350 range and are pretty basic stuff. A shop that does Volvo heads will have the needed selection of adjusting shims.
However it is possible to change the valve stem seals and add new cams without removing the head, tedious and risking dropping a valve but doable.
If you are considering cams, you will want to check the spring pressures and how well the valves seal to the valve seats. It's kind of a "while your at it" situation that can add costs up quickly, and will necessitate removal of the head. At a minimum I'd remove the head and take it to a good shop who has done some fiat heads in the recent past. Have them clean it, check for cracks, check the spring pressures, valve to valve guide clearances which will determine if you need new valve guides, and lap the valves to ensure they seal. Those services should run in the $250-$350 range and are pretty basic stuff. A shop that does Volvo heads will have the needed selection of adjusting shims.
However it is possible to change the valve stem seals and add new cams without removing the head, tedious and risking dropping a valve but doable.