12 replies to this topic

[croc7]

On all eight or just intake?

[Spider]

8

[OzOAP]

I use 8 but take springs off exhaust seals

[r.tec]

I only use them on the inlet valves. Exhaust valves get much hotter and the rubber deteriorates much faster. Then the inlet channels are under suction while the exhauts are unter pressure.

[whistler]

I use 8 but take springs off exhaust seals

Why?

[carbon]

 

I use 8 but take springs off exhaust seals

Why?

 

I do similar, put old part-worn seals on the exhaust guides. If I don't put them on I get clouds of blue smoke on start-up and much higher oil consumption, but at the same time I want some oil to get to the guide.

 

The idea that exhaust gas pressure will keep the oil from going down the exhaust guide has never worked in any of my (admittedly old) engines. And before anyone asks this is the same even when uing PCV and slightly negative crankcase pressure.

[imack]

Intakes only for me on MED offset valve head. No visible smoke on start up or when running on this engine.
Previous engine with Longman offset valve head only had intake seals too but always smoked at idle, especially if facing downhill and oil running towards guides, never smoked pointing up hill with oil running towards push rod holes.

[croc7]

Don’t like the idea of a smoking exhaust, but can understand the need to oil the exhaust valve and guide.

[Spider]

The issue I have found with any oil going down the Exhaust Valve Stem is that it does burn on the seats and cause pitting of them. The Oil will also burn on the stem, with the ash being abrasive.

 

While most of the time, there is a positive pressure in the exhaust port, there's isn't always so. Oil will get drawn down.

[hhhh]

I would think that the moment when the exhaust valve closes, there will be negative pressure at the guide as the last gases rush out the exhaust system.

[Magneto]

I do all 8, I think on street driven cars as compared to race engines it works just fine.

[Cooperman]

I just fit to all 8. Always have and always will.

Can't see any advantages from not fitting to the exhausts.

[Steve220]

I fit all 8 ?

Edited by Steve220, 25 July 2019 - 04:38 PM.