A Sharp Intake .....

[conrod]

Hmmm - just as things were starting to go well ....

I was giving the inlet manifold a thorough degreasing prior to refitting following the vacuum leak problem, when I noticed something potentially significant.

You'll see from the attached photo that there is a small V-shaped nick in the outer edge of no 6 & 8 inlet ports. These seem to align with the points at which the gasket failed. The question is - did they contribute to the gasket failure, or is it just coincidence? The best way I can describe them is that it's as if the edge of a square file has been drawn across the edge of the port, making a V-shaped groove about 0.75mm deep on no 8 and I'd say 1.5mm on no 6.

If the gasket is placed absolutely central to the bolt holes, the tips of V's touch the raised rubber port seals on the gasket - so I would imagine this must put a strain on them.

It seems to me I have three choices:

1) Put everything back and see what happens - with maybe another failure in a few thousand miles time.Maybe with a dab of silicone sealant over the notches?

2) Buy a new manifold

3) Gently file the notches to make them less acutely V-shaped - might this help reduce the strain on the seals? Again perhaps with the addition of a dab of silicone sealant?

I'm not sure how long the silicone sealant would survive being subject to petrol vapour and high vacuum - not long probably!

Views folks?

[Sidecarbod]

You could clean up the notch with a file then fill it with some metal paste. The slight worry would be that the filler would fall out!

I port matched my manifold up to my heads and cocked up one of the ports in the manifold. I got a local firm to fill in my mistake with ali weld, I then filed it back into the correct shape. I reckon is half an hours work judging by your pictures

Pete

[TINKA]

Can't really see you have a problem. I would just take a file to them and go from there. Apart from a continually changing vacuum there is no other real stresses placed on this. JMHO

[TINKA]

Looking at your pictures more closely, it looks like the area where the nicks are, aren’t even in contact with the gasket any way so if this is the case you will be fine to either leave alone or completely file them out as this in effect will just open up the size of the port slightly.

[V8burble]

It looks more like the gasket failed last time due to it being squeezed/stretched up almost above the contact area, so the gasket was not offering the full contact width and so a weak area. When you place the new gasket does it contact the mating faces better?
As for the nicks... I don't think they are anything to worry about, as said, if you want to file them out then fine, but watch you clean up the filings 100%.

[brian twigg]

I would have thought that a smear of metal filled epoxy over the damge, leave for a day to thoroughly harden, then file flat.

Make sure the area is well cleaned with Meths or cellulose thinners befor applying.

Metal filled epoxy can be purchased in a twin tube pack, similar to araldite and is mixed and applied in the same way.

It is very strong when hard and files like metal.

Regards,

Brian.

[V8burble]

Originally Posted by brian twigg

I would have thought that a smear of metal filled epoxy over the damge, leave for a day to thoroughly harden, then file flat.

Make sure the area is well cleaned with Meths or cellulose thinners befor applying.

Metal filled epoxy can be purchased in a twin tube pack, similar to araldite and is mixed and applied in the same way.

It is very strong when hard and files like metal.

Regards,

Brian.

But why bother to fill anyway The nicks are well inside the gasket line... if really bothered by the nicks then file them out rather than fill with something that could come loose one day. If it were mine I wouldn't bother doing anything with them, but concentrate more on doing a good job of fitting the new 'good quality' gasket set

[wilf]

NO filler in intake ports- it WILL end up in the engine.

Can't see a big problem with those nicks - just chamfer them off a touch, and stick the new inlet maniold gasket in place with a little (!) RTV, espec around the water channels, drop the manifold loosely on top and let it set, couple of hours is enough, whip the manifold off again, then a smear of rtv around the manifold side of the water channels, and check, double, and triple check the gasket doesn't move when you finally reseat the manifold.

[grahamf]

Alan
Give me a shout if you want a dab of weld on them. As Wild said, filler, no matter how sticky it is, will end up down the bores!
Graham

[Sidecarbod]

Originally Posted by grahamf

Alan
Give me a shout if you want a dab of weld on them. As Wild said, filler, no matter how sticky it is, will end up down the bores!
Graham

I agree, even though in my first post I did suggest it as a possible cure in my experiance not much will stick well to ali. I either would not bother fixing the nicks but if you are in doubt then a blob of weld will do the trick.

Pete