clearances and other perfromance questions

[seeker1056]

does anyone know what is the clearance between valves n pistons is on a stock motor - and what is the minimum valve clearance one can get away with.

With a max effort motor will it work ok at say 13-14:1 or so compression - we will have the gate set for 60 psi boost this year.

if one moves the IP one tooth on the gear how does one go about timing the pump properly? I do have a degree wheel, and will be determining and marking "actual" tdc and I also have the VW style timing indicator however it reads in inches not mm so I will have to do the metric conversion unless someoen knows what timing is at various tenths or hundreths of an inch.

If i understand things correctly the 93 pump ksb retards timing with power on? If so, does it do that at all times when energized? If so can I set my race timing at say 26 degrees, and use the ksb to retard the timing for road driving to and from the pulls?

We are gettin a new motor ready for the pulling season and with the exception of new pistons this will be as all out of an effort as can be

The build will be based on these already aquired parts:

Cam with CR lifters, maximum timing, big fuel supply and supply lines, 4000rpm "354" spring, dual feed IP, 14mm head/rotor, severely ported head, prostreet 66 turbo (possibly a Pro52 or sledpuller) ported exhaust manifold with an open 3" spacer, air shutoff, turbo bellmouth, cold air supply, cooled fuel, water air intercooler and all 3" piping, 5" exhaust, fire ringed head, 6 x 18 edm injectors

Last question - anyone with proven performance suggestions for this build - We need every "reliable" hp we can get as we are getin ready to chase the points championship in Pro Street this year here in Ontario.

If your not comfy postin suggestions - email me - your secrets are guaranteed safe and priveledged.

I think we can put the run on the electronic boys and definitely on the two P-pumpers in our class - if we can put the "whole" package together.

Thanx in advance for anyone who can and does help out

Ken

[PToombs]

On the KSB, you have it backwards. Power on is advanced, about 7*. Pre-91.5 trucks were power on retarded.

[seeker1056]

well i have several of each so its all good that way

[KTA]

Clearances on these motors can vary quite a bit, especially depending on what has been done. Roughly the pistons usually come out of the block .020" the head gasket crushes to about .057" on a stock thickness, and the valves are recessed in the head about .050". So piston to valve clearance since a stock cam has no overlap is .050+.057-.020= about .090. I recommend keeping piston to valve clearances at least .060". I also think that 13-14 is too low of compression for a small single puller like that. I would try to stay in the 15-16 range to keep up torque and to keep from going under the turbo on the big end.
In other news you have your facts confused on how the ksb functions. On the 91.5-93 version the ksb powers on to advance timing and turns off to function normally. The old wax motor KSB powered on and heated up to retard the timing and powerd off to lock advanced.

[Begle1]

The KSB just maxes out the timing piston in the bottom of the pump, right? So it shouldn't make any difference above a certain case pressure?

[seeker1056]

thanx KTA for the clearance specs

And I will fergit about the ksb thing - it was just a thought to make street drivin more managable if necesary

Any other thoughts on this build?

Ken

[cummins king]

who did you get the cam from? or is it a re grind?

[rockjeep73]

keep the compression as high as possible with the ve pump and small turbo. Also run a stock thickness headgasket so that you can run more timing and keep the spray pattern in the bowl. What pistons are you running?

[seeker1056]

as the build says - stock pistons - however i had been considerin fly cuttn them slightly from readin a lo tof performance posts on other sites

but then thats why I am herre askin questions - the other sites dont know VE stuff

The cam is a new PDR that I got super cheap off EvilBay