Geneqco

I've been thinking about solid lifter conversion... I've been a bit concerned about the extra maintenance and cost associated with that. It also has a hgih initial cost.

I realize I can't really get higher rpm, which is the reason most go that route on other cars, due to the oil pump... in any case, I'm not sure I'd like to go above 7,000 rpm due to the added stresses anyway.

For me, it's more about avoiding potential issues with the hydraulic lifters collapsing, possible better cam profile allowing quicker spool up, and being able to run higher levels of boost... I'm told that even with a valve spring upgrade, you shouldn't really run more than 18 psi of boost with the hydraulic setup.

I wold appreciate any thoughts and/or experience people might have with this setup... especially wrt maintenance costs.

Thanks.

xsboost90

huh- never thought about running high boost w/ hydraulics but im sure there is something to be said about it. High compression would collapse the lifters w/ lots of boost. If you are considering solid lifters and 7k rpm i would think about knife-edging the crank and lightening plus putting some baffling etc in the pan to keep the oil put- ideally dry sump would be the way to go as well with high rpm but $$$ching! I dont think i would be too worried about the extra maintenance involved as adjusting 8 solid lifters would be pretty simple- much easier than a v8 ive done solid lifters on them before whew...

333pg333

Scott there's also upgraded springs that can handle higher pressures of course.

Geneqco

Thanks for the reply Dan,

yeah, i don't really want to get into dry sump at this stage, so I'll keep it below 7,000rpm. i do have a windage tray which incorporates crank scapers and also an Accusump.

I have just bought a 3.0l crank so think I'll do a 2.8 stroker. I was going to go knife edge, but may keep it simple... it's a lot easier and less costly to take weight out of the flywheel and it's easier to make changes if need be... any thoughts on that?

Geneqco

Thanks Patrick,

Problem is, i'm told there's a limit to how strong a spring you can use with hydraulics before they will start to give you problems... according to LR, that spring combined with hydraulic lifters really limits you to 18psi if you want to play it safe with the hydraulic lifters.

Rogue_Ant

Didn't ST have hydraulic lifters for some of his high-boost runs?


Rogue

A.Wayne

Solid lifters are not necessary unless you are running high rpm and a very big cam , race engine maybe ?

333pg333

My info tells me a few different things. I'll let you know.

Geneqco

What about higher boost levels... how do the old hydraulic lifters handle that? What would be a reasonable limit for boost pressure with hydraulics?

Thanks

A.Wayne

Valve spring seat pressure is of a bigger issue with high boost than lifters , some valve float issue's in relation to high boost can come from improper tuning and poor intake manifold design. If you are using stock lift cams or a slightly modified cam with stock base circle , there should be no need for an upgrade.... unless of course you have worn lifters .

NZ951

So the three years I ran 22-23psi doing DE and drag events was a just good luck?

NZ951

I dont know how often people are spitting out shims with popular cam profiles without shimless bucket conversions in the 944 world?

To be honest, it looks like a solution in search of a problem. Sure theory at extremes tells us it helps solve a problem at some point, fact is there are countless examples with people running aftermarket cams and high boost and dont have lifter failure.

Its something I am considering with my V8 project, using 1N / 2N shimless buckets (or welding the shimless on the stock buckets) when I go to a 10.5mm lift cam with aggressive ramp cam.

Geneqco

Thanks... Yes, they are saying the valve spring is the limiting factor, but they are also saying the valve spring you use is limited by the hydraulic lifter... ie, you can't really run as stiff a spring as you might like with tha hydraulics... also, because of the lighter valvetrain weight with the solids, the spring needn't be as stiff for the same boost pressure.

Any comments?

Geneqco

Thanks NZ951,

That was the other point, they cay you can run a cam with a more aggressive ramp with solids which they say can really help spool the turbo much more quickly.

Comments on this aspect as well any other benefits you see in the aggressive ramp cam would be greatly appreciated.

NZ951

The only reason I would run solid lifter would be to run a really aggressive ramp cam, but depends how nice you want your idle! For my mind, this is a complete waste of time for any car which spends less than half its life on the track.