[SSE 4 2SS]

Originally Posted by stevieturbo

Not really..I'd say it's mostly down to heat. Any cams I've used etc have all been pretty mild. I like a smooth idle.

Although...I've only been LLSR for 2 years and I cant comment at what length the valves were prior to this. Using Ferrea 6000's so should be a decent intake valve and I replaced them with the same ( and inconel exhausts that oddly all measure slightly shorter than spec'd lol so not changing them )
It was only after the one standing 1km run I got this year I noticed the clearances tighten up on a couple of cylinders ( only got 1 run, clutch started slipping after )

So I would think the valve stretch has simply been over time and chamber heat related, but only became noticeable with the solid roller as you have a reference point. ie valve clearances.
Although LLSR aims for around 10thou when warm, I may run these a little larger this time around.

Pump fuel ( and meth ) and long duration pulls do generate more heat than expensive race fuels etc so I'm putting it mostly down to that.

Race fuel is mega expensive here, and certainly no 2wd car even comes close at those events, the only cars to run quicker now are some of the GTR's ( all on race fuel or C85 )
So I think it's even more comical to drive there...and run on pump fuel and still beat most of them whilst driving a 35 year old car.

That said, I may consider some race fuel for 2017, purely as I really want to try and hit 200mph in 1km. I'm only 7mph shy, and for 2017 I've opted for a bigger cam and trying larger turbine housings, so between those I think that might just give me enough to do it, and for one event I can suffer the cost for a drum or two of some race fuel.
I had no backpressure issues...but that little hole inside the turbine housings always bothered me ! So trying a little larger.
One some 4cyl cars I've swapped housings, larger ones just seem to spool the same but make more power up top. So I think it will be a good test.

Dammit Man, 200 mph in one kilometer puts you not too far behind me... I've been 187 at the half mile... with very anemic launches.... Hopefully some changes are coming soon that will help me in that area, I'm hoping to hit 205-210 at least in the half mile... Gotta get this power to the ground and use every available inch of track to accomplish it...