Cam timing and boost troubles
Turbo Mini Forums

Right, since rebuilding my engine I've had boosting issues, it feels like it's holding back loads. The only thing that's changed is the turbo is reconditioned and the engine is now 1310cc and 9.1:1 compression ration from 8.8:1 previously. When I took the engine apart, I took the cam and crank sprockets off together with the chain and cable tied it altogether to prevent loss of timing.

As I was in a rush to get it back on the road, I never checked whether the timing was the same on the cam (Sw5). If it was out a degree or 2, could it cause the effect I'm having? Or am I clutching at straws?

one tooth is 13 or 16 teeth IIRC, thats a lot of timing, would probably half the power or less.

just a thought, the SW5 is the same lift on inlet and exhaust, so with no 1 at tdc you should have no 4 ( or would it be 3) with equal ift on inlet and exhaust ( or very close)

Hi Joe, I'm pretty sure it didn't skip a tooth, the engine actually idles and drives nicely, however it really struggles getting into boost and keeping it steady. Checked everything else and I'm running out of ideas!

Is the dump valve sealing as it should or could it be wastegate related I wonder.

Just a thought.

Exhaust or air filter restrictions?

Edited by Steve220 on 2nd Aug, 2019.

Like Mike leaving a pile of blue roll in the intercooler!

If something is worth doing, it's worth doing half of.

mmm,

could be retarded, when i was faffing with a mates K100 it was flat as a witches tit after about 3500rpm, after cheking the cam timing and advancing it a bit and closing up the LCA it was a totally different car.

for the sake of sticking it on TDC and poppig the rocker cover off I'd check it.