Engine makes noise after overhaul

[Gerke123]

Hello everyone,

We have fixed the engine noise and the engine is running smoothly now! The issue was the headgasket...

The headgasket we ordered was the 80mm version instead of the 84mm version, so the cilinders would dent the metal ring of the gasket that was slightly sticking out.
For comparison, the images attached to this post show the damaged rings, along with the new headgasket that we ordered.

After we (luckily) saw no damage to the engine from the headgasket mistake, we decided to build up the engine again and start it, and it finally ran as it should have from the beginning without that horrible noise.

-Gerke

[SanRemo78]

Glad you've sorted the issue without damage - hands up anyone who suggested that as a possible cause? None of us I guess so another warning to others rebuilding the engines!

Guy

[WestonE]

Well done on finding that and I admit that did not enter my mind as a likely cause.

Eric

[smithymc]

Good result all round and a relief- well done.

Lovely car.

Mark

[HFStuart]

I would have been a long while before I guessed that! Delighted that there's no damage and it's an easy fix.

I guarantee it's a mistake you / you builder will never make again!

[squiglyzigly]

Pleased you found the cause but I can’t help wondering how close the pistons are to touching the cylinder head?
I assume you are running high compression for performance and have had the block skimmed? I’m not familiar with your engine type but I’m not aware of a standard factory engine where the perimeter of the crown on the pistons protrude above the block deck. (I could be mistaken here).
If so, do you have sufficient piston to head clearance to allow for ‘rod-stretch’ when the engine is at higher revs? Otherwise the pistons next stop will be against the cylinder head which will not be quite so easy to hear when the engine is running at higher revs.

Hope it all works out ok.

Kind regards
Ian

[WestonE]

The points Ian is raising are important. If both the block and head have been heavily skimmed a dry build test with plaster cine / play dow on the piston edges and in the valve cutouts is needed. GC's books provide minimum clearances and explain how you test. GC dealt in race engines and higher revs and you probably run to 6500 RPM maximum. However I think you should check this if not already done so.

If the clearances are too close you can use Cometic MLS gaskets in a thicker stack or you take the chance and control the revs.

Eric   

[Gerke123]

Hello,

Thanks for all the comments and concerns, as for the engine, we will do a dry build test later this year and to see if all is within the correct measurements.
However, the engine itself is not built for racing purposes, nor will we use it for that, so it shouldnt see lots of high revs but again, we will get it tested to ensure its fully reliable.

-Gerke