8 replies to this topic

[tomBERTfrancis]

Hi all replaced the inlet manifold gasket yesterday because the old one was blowing out air but after about 1 mile the new gasket is starting to do the same thing in the exact same place again. I checked all the bolts and they all seem pretty tight,engine has just had a complete engine rebuild any ideas?  

[rally1380]

Which gasket??

 

Manifold to cylinder head gasket or manifold to carb body gasket?

 

Either way, if they are blowing the mating faces aren't lining up properly and something is stopping the two faces sitting together. Strip and find the problem....as its not the gasket at fault by the sounds of it.

[tomBERTfrancis]

its the manifold to cylinder head gasket.

[Stiggytoo]

Did you make sure the mating faces were clean and flat? Other thing to check would be excessive engine movement.

[tomBERTfrancis]

yep cleaned the faces.when I put the gasket on it seemed tight to the cylinder head but now it seems to be pushing itself away and making a small gap letting air through.

[Fossy313]

just a thought but could it be your exhaust tugging on it?, have you attached your manifold to the bottom of the gearbox to stop movement?, especially if minis are low and sometimes catch it could be enough to pull the manifold and make the gap, likewise what someone said about engine movement....

 

if not, try and injection gasket they are harder and have a metal plate inbetween. worth a try

[tomBERTfrancis]

its all attached,maybe it would be worth changing the manifold studs and inlet manifold?

[rally1380]

What Inlet and exhaust manifolds do you have??

 

Some have different thickness flanges where they bolt down to the cylinder head.....so you might think they are tight but in fact most of the pressure is on the exhaust manifold (in your case) so not fully clamping the inlet manifold.

 

A way to get round this is either file the mating flange of the inlet manifold....easy on the outer two, not so easy on the inner two.

 

Or......file the thick manifold washers that i'm sure you are using into a step sort of design to take up any difference in flange thickness.

 

Or.....buy both Maniflow manifolds as they use the same thickness material for the flanges and so no problem at all.......not a cheap solution though!!!!!!

 

Hope this helps.

[ChopperHarris]

Inlets suck, not blow