Valve Seats

[ScottArcher]

Hi All,

I am new to the site and just wanted to say thanks before I get started. What a great site!!

Anyways I recently purchased a Sabre 28 and the A4 was already removed. It looked like the prevoius owner who had passed away was going to start working on it.

I did find that one of the valvles was stuck open and one of the springs was broken. I have since removed all the valves, springs etc and cleaned. I now have all valves moving freely.

My quesion is on the valve seating. My engineering background tells me the seat should be smooth and clean. I have done some light lapping using the existing valves and was able to get a smooth finsih on the valve, but not the seat. There all small pits and some line. (see attached pics).

Is their a good solution to get the seats nice a pretty, or is it normal to have some of this on the A4?

Thanks in advance,
Scott

[Loki9]

Those valve seats look horrible and will need to be re-cut. You must disassemble the A4 and take the block and the valves into a machine shop for reconditioning. They will likely deck the surface, re-cut the valve seats, and dress/grind the valves as required.

[ScottArcher]

Thanks for the reply. I guess I didnt notice on my original pictures how bad it was. When I uploaded the pictures to the forum, they were magnified and you can really see the corrosion.

[Dave Neptune]

Seats

Scott, there are set cutting tools available for doing the seats in the boat or wherever the engine is. I needed one to get my engine working over 30 years ago and she still purrs! The valves can be done on there own in a shop, or just buy new~your call.

The seat cutter is an easy tool to use on the A-4 as long as you have some room above the block.

Dave Neptune

[lat 64]

Like Dave said, Valve seats can be done in the field, You will need a shop vac to suck out the grit from the work. plan on lots of dust and/or shavings. Stick rags where you think it might need to block out grit.

It kinda looks like water has got in to the intake. Probably from backflow from the exhaust. There are many posts and discussions on this forum about how to avoid that.

Russ

[Loki9]

Scott, there are set cutting tools available for doing the seats in the boat or wherever the engine is. I needed one to get my engine working over 30 years ago and she still purrs! The valves can be done on there own in a shop, or just buy new~your call.

The seat cutter is an easy tool to use on the A-4 as long as you have some room above the block.

Dave Neptune

His A4 is already out of the boat, so plenty of room to work.

Yes, you can cut the valve seats yourself, but with an A4 of unknown history and already out of the boat, why would you stop at head/valve removable? Break it down all the way, check the bearings, do what needs doing...

[ScottArcher]

Thanks for all the replies! All good advise. The lower halve of the engine appears to be in good working order. I will be checking with Moyer to see if they still rent the valve cutting tool.

[hanleyclifford]

Also check those valve guides for ID. There is no point in regrinding if you don't have a stable center.