Cracked (newish) B18 pistons

[Sam Glover]

Originally Posted by arcturus

The pic's of the valve seats. is that the exhaust valve on the right and if so should it not be recessed? should it be as in the other side. Is this an example of valve recession and if so what would be the likely outcome. would it affect efficiency? Apart from lifting head are there any warnings signs that would be noticed?

Yes, that’s the exhaust valve on the right – and no, it shouldn’t be recessed. It should look the same as the inlet seat next to it. It’s not the end of the world, as long as you keep an eye on your valve clearances. The rate of recession was high in my case because the 3000 miles included a lot of high-rpm motorway driving and a 1000-mile rally in the French Alps. With gentle use, it’d be far slower.

Fitting hardened valve seats is a cheap and relatively non-specialist task. You could do it yourself with a press and a valve seat cutter.

Volv5.jpg

[Sam Glover]

Originally Posted by swedishandgerman

If it was built up by who I think I remeber it being done by, i would be very surprised if they did it wrong.

I’m not sure there was much evidence of the engine-builder knowing what they were doing. It had a new camshaft and here’s one of the followers…

Volv6.jpg

[grumpydad]

Hi
pistons I would go to http://www.wiseco.com/Catalogs/Automobile.aspx
or try caffyns volvo tel 01323 344510 ask for chris in parts he has been very helpful with bit for our amazon estate did you know you can go out to 2.3 by using B230 pistons

[swedishandgerman]

Originally Posted by Sam Glover

So: where can I buy pistons that match the quality of Volvo originals?

This may sound crazy, but I have bought genuine stuff from Volvo for my oldies at competitive prices.

If you ring Kastner Volvo in Exeter on 01392 201040 and ask for Jim. Tell him Adam put you in touch and make sure you have half and hour spare because he LOVES talking about old Volvos!

I thought the engine was done by Amazoncars, but I would have thought that he would most definitely know to put in new followers with the new cam that I recall your car was fitted with. As well, I recall the previous owner having the 123 distributor and carbs all set up on a rolling road, so it's interesting to read that neither were right. I wonder which setting the 123 distributor was on - from memory, it was a standard 123 distributor and not a 123 Tune. If a proper B18 twin carb distributor was unavailable, then they should have put it on the B setting. I wonder why they didn't just put the standard needles in there.

[Vintagewrench]

Here in the US the generic replacement cast pistons for vintage Volvos and domestic brands offered by suppliers are of low quality when compared to the high quality Malhe Volvo pistons available years ago.

I have switched to having forged pistons made here in the US by the some of the better piston companies and have never had an issue w/them. Some of the high performance vendors of early Volvo parts in Sweden and the Netherlands also offer B18 and B20 forged pistons.

Originally Posted by Sam Glover

I’m not sure there was much evidence of the engine-builder knowing what they were doing. It had a new camshaft and here’s one of the followers…

This is a lightened racing lifter (note the extra crosswise holes) made in the same pattern as those offered by Volvo Competition Services back in the day.

If this was a new lifter installed during the rebuild it appears the issue was not it, but was either a bad cam or an improper break-in period (run at 2000-2500 rpm for the first 20-30 minutes of operation) or lack of break-in lube on the cam. This video shows the correct procedure. https://www.youtube.com/watch?v=re-VqHO3cH8

If you note the wear pattern, this lifter has not been rotating like it should. Cam lobes for flat tappet lifters are ground on a slight angle which keeps the lifter rotating so it wears evenly and does not gall like this until it has covering a lot of mileage.

This type of lifter is also not centered over the cam lobe but offset to one side to help promote rotation (note the wear pattern is off to one side.)