I personally think you should give it to me... solving all this running/not running/potentially lumpy running issues
I spotted it then The new heads (AMC) all have the same valve sizes regardless of cc, in fairness to your builder if he ordered what is advertised as an 1800 head why would he expect it to be different, also he may have built up the engine to short block with one head and fitted the second ( new) head without comparing them, it's an easy fix though
Hang on I'll get me torch.... I should be in bed you know, it's well past my bedtime and I've got a phone call to make in the morning
I said a few post back, I'm coming to Scotland to give you one. X That's just to be going on with 'cos my vans not working at the moment.
Yeah lets not take over bobs thread with the science of bhp and torque at different rpms After all stump puller engines aint popular in the uk
Going on the chart values, you're looking at 5BHP less, and 10ft/lbs of torque less... But that is book values, which as we all know, are never right
Seriously? Not questioning you're integrity, but I'd be extremely surprised if a nailed on 15BHP increase was down to the valve size alone...
Isnt the issue that if you have a significant power imbalance between one side and the other it will trash the bottom end a lot quicker!
Given that you've had new Bs & Ps etc....i think you'll be more than happy with the engine, compared to the previous output once the head issue has been sorted, and everything's run in
Its not just the valve size but the ports aswell I have ported heads that have given 10 to 15 bhp extra with no other mods at all The first stage of tuning is to increase flow and if you do this by doing what isnt economicaly viable in mass production then apart from the effort and time involved its a free power gain Just matching the inlet and the port to the size of the gasket makes a massive difference