valves at cylinder 1 and 3 tight

[jarmchairpilot]

I rebuilt my 1200 bug engine and have run it in and put over 170 miles on it, just checked the valve gaps that were set at 0.15mm are now normal on cylinder 2 and 4 but had tightened up to zero lash for both valves on 3 and the exhaust valve on cylinder 1had gone to zero lash.
Any idea what's up?
I have redone all gaps to 0.15 now and will change the oil at 200 miles.Thanks.
Bug drives ok up to 40mph but then won't go much past 45mph?

[Evil Clown]

Let it cool down overnight & re-check...
If it continues, it maybe the seats
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CARRY ON

[goober]

Assuming you did a decent rebuild, I'd check/adjust the valves every couple hundred miles and see if things stabilized by a 1000.

Not sure why it won't go over 45 mph. Did the heads torque up ok?

[Eric&Barb]

[jarmchairpilot]

Heads torqued up fine, I noticed the original vw German pistons had a convex domed top but the new AA ones are flat, maybe that lowers the compression still that would apply to all cylinders.
I hope it's just an engine running in thing...but I doubt it.
Don't think there is anything I can do now apart from an oil change and hope the 200 mile mark the engine will have settled in. I will have to check the valve gaps frequently.

[goober]

Not sure what the symptoms would be if your valve timing was off. Did you double check the marks?

[challomoner]

[RWK]

Time will tell on the valve lash, make sure your throttle cable is adjusted correctly, may not be getting W.O.T. that's a simple check, but takes 2 people.
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73 Type 181
63 Type 113
63 Type 261- 428 071
62 Type 241-378 025 178 530

[mukluk]

You say AA pistons were used during the rebuild of your 1200. Something that immediately comes to mind is those particular pistons are known to have a different piston pin height than original parts, resulting in a rather large deck height and lower compression ratio unless the case is decked or the cylinders shaved. Did you measure your deck height and calculate your compression ratio with the new pistons?
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1960 Ragtop w/Semaphores "Inga"

[jarmchairpilot]

I didn't measure deck height or check compression ratio.
I could not find any domed pistons of the correct size anywhere in the UK websites.

[jarmchairpilot]

I reused my original German, single ports with new valves of Italian make, with new stock springs and chromoly retainers. Stock vw cam,lifters and rockers.

[mukluk]

[jarmchairpilot]

I fear mukluk is correct and the good news is the engine is settling down so the valve gaps are becoming more stable but the compression ratio is lower due to the aa pistons, can only guess but it feels like the engine has lost a substantial amount of torque and hp compared to the og German vw domed pistons and barrells.
So much for today's hi tech advanced, close tolerance computer controlled machines!
Disappointing.
Also I have had a problem with the manifold icing up under the carb when there was some freezing cold,damp weather lately, despite my fully cleaned out heat risers during the rebuild.
It left me stuck on the side of the road one night as all power died, the engine would idle but die as soon as put in gear...had to get towed home, drops of water in manifold.
I blew an airline from a compressor through the carb and some fresh petrol got things going again.

[sjbartnik]

[jarmchairpilot]

Didn't because I bought the only p+b option available at my local dealer, I don't have access to a machine shop, despite the fact I actually work in one it's not allowed and the bug is my daily driver I was on a tight turnaround time of 4 weeks before the use of a loan car and temp. insurance was up. In fact I has spent a thousand bucks on parts already meant I wasn't going to spend more getting machining done or buying more precision measuring equipment, I made do with a Vernier calipers pretty much. A stock 1200 is not worth much more.

You gotta work with what you got, I did a lot of overtime for a while so I could afford now to get a bore gauge and/or micrometer now if I wanted.
I am grateful for the advice here of more experienced mechanics and I am slowly learning more with the help of the great Samba community.
Thank God it's not full of "mine is bigger than yours" keyboard warriors that ruin most online forums!