Having just purchased a new cylinder head (heavily modified and skimmed a couple of times) and cams QED Q38H cams. I have a few questions relevant to the fitting and timing of them. Having found out the required timing of the cams from QED being 114/114, what is the timing of the standard XE cams? So I know how many degrees to change the verniers.
Another question with the hydraulic lifters is, how long do they stay pumped up for after the engine being turned off? And do they pump up when the engine is being turned over?
Q38HA more vigorous hydraulic profile not liked by Motronic ECU's, but if fuelled correctly, with a standard induction system can produce c200 bhp. With carbs or throttle bodies 210+bhp is easily achieved. Possible to fit without piston mods, but pistons with deeper valve pockets are required for optimum cam timing.
The 114/114 is for the standard XE pistons, however I may get an engineer friend to machine them for me!
.. Having found out the required timing of the cams from QED being 114/114, what is the timing of the standard XE cams? So I know how many degrees to change the verniers...
Do you have the full spec of the cams mate?
Anything would be useful.
I don't see why you should have to 'time' them yourself, you've already paid good money for QED to do it for you, didn't you?
The only reasons (I can think of) to warrant verniers would be:
1. your true TDC is found to be off a few degrees and you want to adjust for that
2. your engine's state of tune is different from what QED accounted for, so you try to adjust the cams so that they work optimally on a different setup
3. you simply want to experiment a bit, and probably return to their stock settings later.