3 replies to this topic

[oh.go.on.then]

Evening all, I’ve just removed my 12g295 head while doing other things to check and de-coke. I kind of wish I hadn’t as I noticed a valve guide looked really low or protruding into a chamber. Turns out it is loose and easy moved up to be in line with the others.
I hadn’t planned on spending any money on the engine as I’d planned to put it in the corner of the garage and build a larger engine at some point such as 1380. It is in a mk2 cooper so I need to keep the engine for originality regardless.
Has anyone had a loose valve guide before? I presume they can be fitted oversized?
If I’m doing that I presume I may as well fully re-build the head with new valves,guides and seats. Does anyone have any recommendations near to Worcestershire that could do this and potentially gas flow at the same time?
As I say, I’m loathed to spend money on it but one way or another I’ll need to make a decision.
Cheers

[Turbo Phil]

Unless you're looking to get every last HP from the 295 head don't bother paying to have it ported. The most substantial gains are made by fitting larger valves, especially on the inlet, as an increase in valve size allows a multi angle seat to be cut and blended into the throat. 
This video shows the gains made without even touching the ports. 

 

 

Phil. 

[oh.go.on.then]

[quote name="Turbo Phil" post="3667242" timestamp="1601074162"]
Unless you're looking to get every last HP from the 295 head don't bother paying to have it ported. The most substantial gains are made by fitting larger valves, especially on the inlet, as an increase in valve size allows a multi angle seat to be cut and blended into the throat.
This video shows the gains made without even touching the ports.


That’s a useful video actually Phil. Looking at the website the prices don’t seem too bad either. I will give them a call but they are a long distance from me so I wonder if there is anyone close to Worcester that could do it. I’m old school and prefer to go and see someone than post it!

Edited by oh.go.on.then, 26 September 2020 - 06:16 AM.

[Turbo Phil]

No worries. If you can’t find anybody local, and you’re not in a rush let me know.

Phil.