no valve clearance

[Laird Scooby]

Originally Posted by volvulus

Oh I see. I took the exhaust valves out one at a time. I didn't remove the inlets.

I sprayed LO 30 degreaser in all the ports to leak test the valve seals, only number 4 exhaust showed any signs of leakage.

Regards ken

Have you tried laying a straight edge along to top of the valve stems to see if #4 exhaust valve (i'm guessing from your comments this is the one you changed) is any higher than the other valve stems?

Also if the cam carrier wasn't bolted down evenly it could be distorting and causing the cam bearings to be slightly out of line - this will also prevent the camshaft turning.

It would help if you could post some pics of the whole thing with close ups of any potential problem areas - there might be something blatantly obvious to one of us but perhaps not to you for a variety of reasons.

[baggy798]

You'd have to huff a lot of meths to mix up the 530 valves..

https://cdn.ozvolvo.org/uploads/287/O145JX4EJSRB.jpg

Have you tried rotating without that valve and just the bucket in to rule out any of the others for damage? Could the stem of another be bent causing binding?

Had to ring for ages the last couple of times to get through to my volvo dealer as no one on reception. New people there now, perhaps standards are slipping.

[volvulus]

Thanks Baggy, that's my next job. Don't think any other stems are bent or the they wouldn't have passed my leak test.

And Dave... it's No 3 I changed, No 4 was the only one showing leaking LO 30.

I'm going to try measuring with a straight edge if I don't have a big enough micrometer.

Many thanks all ken

[Rversteeg]

Would a valve that is too long not just stay open all the time? It should still be possible to rotate the camshaft. I can only imagine that if the top part of the stem above the spring is longer the spring will be fully compressed before the camshaft is at full lift. Can you still compress the valve like you do when adjusting valve clearance?

Volvo does not sell shims below 3.3 mm, but for LPG engines running short on valve clearance you could go as thin as 3.0 or even somewhat beyond that. The limitation is in the outer ridge of the bucket itself. If the shim is too thin, the cam will strike this ridge and be damaged. The bucket size does not seem to be consistent, as the minimum shim size varies from engine to engine.

[volvulus]

Originally Posted by Rversteeg

Would a valve that is too long not just stay open all the time? It should still be possible to rotate the camshaft. I can only imagine that if the top part of the stem above the spring is longer the spring will be fully compressed before the camshaft is at full lift. Can you still compress the valve like you do when adjusting valve clearance?

Volvo does not sell shims below 3.3 mm, but for LPG engines running short on valve clearance you could go as thin as 3.0 or even somewhat beyond that. The limitation is in the outer ridge of the bucket itself. If the shim is too thin, the cam will strike this ridge and be damaged. The bucket size does not seem to be consistent, as the minimum shim size varies from engine to engine.

ok.... I remembered I have a depth micrometer, so... the new (after market)valve
is 0.022" inches longer than it's neighbouring exhaust valve. That valve is giving a gap of 0.020" or gnats over 0.5mm. So if I can engage my brain I can work out what size shim I would need for new valve. (unless I get a Volvo valve)

Now there are no hushers ( or what remained of them) I have bigger gaps than when I measured before strip down.

I might do better to order a volvo valve and all new shims. I don't know how critical the gaps are but they are as follows...

1; 0.021" 2; 0.018" 3; 0.019" 4; 0.019" 5; minus 6; 0.018" 7; 0.020" 8; 0.018"
ex

number 1 being front of engine. Sorry they are in imperial. I'm trying to move over to metric....I'm getting there inch by inch!!!

The cam now turns fine, I had the centre caps back to front... couldn't read the numbers properly.

Cheers Ken

[Laird Scooby]

Originally Posted by volvulus

ok.... I remembered I have a depth micrometer, so... the new (after market)valve
is 0.022" inches longer than it's neighbouring exhaust valve. That valve is giving a gap of 0.020" or gnats over 0.5mm. So if I can engage my brain I can work out what size shim I would need for new valve. (unless I get a Volvo valve)

Now there are no hushers ( or what remained of them) I have bigger gaps than when I measured before strip down.

I might do better to order a volvo valve and all new shims. I don't know how critical the gaps are but they are as follows...

1; 0.021" 2; 0.018" 3; 0.019" 4; 0.019" 5; minus 6; 0.018" 7; 0.020" 8; 0.018"
ex

number 1 being front of engine. Sorry they are in imperial. I'm trying to move over to metric....I'm getting there inch by inch!!!

The cam now turns fine, I had the centre caps back to front... couldn't read the numbers properly.

Cheers Ken

Hushers make a difference to the measured size but not to the actual clearance so need removing before checking the clearances - as you've found!
From the front it's exhaust-inlet-exhaust etc so the odd numbers are exhaust valves and evens are the inlets.

You need to measure the size of the shims on the valves that are outside the clearance and work out from there what size shim you need - also have you lapped the valves in, particularly the new one? That could also make a difference to the measured clearances.

The valve clearances are 0.30-0.40mm, adjust to 0.40mm, in old money 0.012"-0.016", adjust to 0.016".

From what i can see so far, you have :

1; 0.021" - Shim needs to be +0.005"
2; 0.018" - Shim needs to be +0.002"
3; 0.019" - Shim needs to be +0.003"
4; 0.019" - Shim needs to be +0.003"
5; minus - ????????????
6; 0.018" - Shim needs to be +0.002"
7; 0.020" - Shim needs to be +0.004"
8; 0.018" - Shim needs to be +0.002"

If you haven't already lapped the valves in, i'd lap them in and recheck your clearances. You may find you don't need to do anything. I assume you've tightened the cam carrier down as it should be before checking already?

Once you have a definite set of clearances, you need to measure the shims on those that are out of adjustment and calculate from there what size you need.

With the valve clearances for the most part larger than they should be, the engine will sound clattery, the valves won't be opening properly so you'll be compromising performance and economy. Also by lapping the valves in you will improve the gas-tight seal of the valves so gain a bit of compression there as well.

[volvulus]

Originally Posted by Laird Scooby

Hushers make a difference to the measured size but not to the actual clearance so need removing before checking the clearances - as you've found!
From the front it's exhaust-inlet-exhaust etc so the odd numbers are exhaust valves and evens are the inlets.

You need to measure the size of the shims on the valves that are outside the clearance and work out from there what size shim you need - also have you lapped the valves in, particularly the new one? That could also make a difference to the measured clearances.

The valve clearances are 0.30-0.40mm, adjust to 0.40mm, in old money 0.012"-0.016", adjust to 0.016".

From what i can see so far, you have :

1; 0.021" - Shim needs to be +0.005"
2; 0.018" - Shim needs to be +0.002"
3; 0.019" - Shim needs to be +0.003"
4; 0.019" - Shim needs to be +0.003"
5; minus - ????????????
6; 0.018" - Shim needs to be +0.002"
7; 0.020" - Shim needs to be +0.004"
8; 0.018" - Shim needs to be +0.002"

If you haven't already lapped the valves in, i'd lap them in and recheck your clearances. You may find you don't need to do anything. I assume you've tightened the cam carrier down as it should be before checking already?

Once you have a definite set of clearances, you need to measure the shims on those that are out of adjustment and calculate from there what size you need.

With the valve clearances for the most part larger than they should be, the engine will sound clattery, the valves won't be opening properly so you'll be compromising performance and economy. Also by lapping the valves in you will improve the gas-tight seal of the valves so gain a bit of compression there as well.

Well it was certainly gutless on hills or pulling away and, my mpg was 25 on a good day. ( not checked it for years) went like dream on cruise. My step dads 2ltr turbo was much more powerful.

I was wondering if I could lap the valves in enough to bring them, (or most of them) into spec. 5 thou is rather a lot though. The one I lapped in, No 7, increased the gap compared to the pre- strip down so I would have to go some to get my gaps.

If I did this I would need to buy or make a tool for removal/ installation of the valves. Maybe buy a tool for compressing the valves in order to change the shims with the cam bolted down.
I did lap in the new one yes.

I wish I had persevered looking for original spec volvo parts. After market is a minefield, with my other cars there isn't always an original spec option, it's a hot topic in the classic world but, as the suppliers say... if we charged what it would cost to make the proper spec parts most people would still opt for the cheaper inferior option.

Kind regards ken.

[Laird Scooby]

The big difference between yours and your dads is the turbo, if memory serves the B200FT is 155bhp and yours struggles to about 110-115bhp on a good day.
Yours will never be a ball of fire in terms of performance or economy because it's the most underpowered of the 7/9xx range and hence throws fuel in just to get going, never mind doing things like accelerating or going up hills.

Do you not have a valve spring compressor? I think you used Lukes trick of a large G-clamp and a Lambda socket to change the exhaust valve, you could use the same to change the shims or you can buy tools for about a tenner to depress the valve to change the shims. Alternatively, once you've removed the cam carrier for access to the shims you can hook them out one by one and measure them, replacing as you go then calculate the shims you need from there.

[volvulus]

Originally Posted by Laird Scooby

The big difference between yours and your dads is the turbo, if memory serves the B200FT is 155bhp and yours struggles to about 110-115bhp on a good day.
Yours will never be a ball of fire in terms of performance or economy because it's the most underpowered of the 7/9xx range and hence throws fuel in just to get going, never mind doing things like accelerating or going up hills.

Do you not have a valve spring compressor? I think you used Lukes trick of a large G-clamp and a Lambda socket to change the exhaust valve, you could use the same to change the shims or you can buy tools for about a tenner to depress the valve to change the shims. Alternatively, once you've removed the cam carrier for access to the shims you can hook them out one by one and measure them, replacing as you go then calculate the shims you need from there.

I don't have the proper valve spring compressor. If that is a tenner then it's money well spent but it's finding one.

I've got a couple of the usual compressors but they don't work on the volvo. I could maybe make an extension with a slot in from a piece of tubing.

I used Lukes idea but my G- clamp is very heavy and large! The Lambda socket contact area is marginal, ok for one or two valves but I'm not happy with doing more.

Thanks for your help Dave....and all who posted.

Regards Ken

[Laird Scooby]

Originally Posted by volvulus

I don't have the proper valve spring compressor. If that is a tenner then it's money well spent but it's finding one.

I've got a couple of the usual compressors but they don't work on the volvo. I could maybe make an extension with a slot in from a piece of tubing.

I used Lukes idea but my G- clamp is very heavy and large! The Lambda socket contact area is marginal, ok for one or two valves but I'm not happy with doing more.

Thanks for your help Dave....and all who posted.

Regards Ken

I've just had a look on fleabay Ken and the prices have gone up considerably since i last loooked 2-3 years ago. However i did find this :

https://www.ebay.co.uk/itm/353699303968

Extensions as part of the package with a variety of heads to fit different valves. The type of compressor i was looking for that you can use without having the head on the bench no longer seems to be available other than universal ones that hook onto the cam shaft and then depress the valves - not suitable for yours with direct acting lobes on the valve buckets.