Convert leaded head to unleaded - how?

Convert leaded head to unleaded - how?

Author
Discussion

vrooom

Original Poster:

3,763 posts

268 months

Monday 1st March 2004
quotequote all

Im looking at big bore head its in leaded, i want to put it to unleaded. how much will that be and is it easy job to do?

Thanks

jay

Plotloss

67,280 posts

271 months

Monday 1st March 2004
quotequote all
You'll need to get the valve seats and guides replaced with hardened jobs I think.

Its a fairly straightforward job for an engineer...

Then its just a case of swapping the heads.

Paul V

4,489 posts

278 months

Monday 1st March 2004
quotequote all
You might better finding a second-hand one thats already been done. You’ll also have to check that the valves aren’t too big, as you might not get the hardened seat in.

Cooperman

4,428 posts

251 months

Monday 1st March 2004
quotequote all
With unleaded seats you certainly can't get the big valves used in the race and rally cars in unless you modify the valve centre line positions, which is not worthwhile unless you want absolute maximum power.
On cars with biggest valves in standard positions we normally run leaded and use Castrol 'Valvemaster' or similar lead replacement stuff

Paul V

4,489 posts

278 months

Monday 1st March 2004
quotequote all
I used castrol valvemaster plus in my 1380, the extra octane seemed to help it run well