Hi All. I have just transplanted a Slick 50 8v motor into my A reg mk2. I have performed the 16v WUR mod but without fuel pressure gauges I am adopting the trial and error method. Can anyone tell me; 1) which way you turn the allen screw to turn up the pressure? 2) Timing is currently spot on and I have set the CO2 to 3.2, but as expected it pinks badly under load. Would you advise retarding until acceptable? I was advised to set the CO2 higher than normal. Tick over is high but I guess this is the norm for a cammed motor? Pulls really well but as mentioned it pinks badly. Compression is 175 on all. Oil warning buzzer sounds occasionally?? I have changed the switch so I guess/hope its the wiring? Cheers
I actually did mine through trial & error & when I eventually checked it with a pressure gauge I was only around 0.5 psi out. But as Pigbladder said def best to do it properly, I was just lucky
Ah, then I may give it a go anyway ujntil i find someone with guages. Just retarded it slightly and got rid of the pinking. Thanks guys.
Yes it definately would be, but I just want it driveable for now! Fed up of driving my T4 camper every day and dont want to tax the damn thing again... Impatient, me!? Correction to previous post; It still pinks, a bit...
Re the oil light buzzer; This is concerning me a little. High revs no light/buzzer, but as the revs drop of under load the light/buzzer come on (but not always). A blip of the throttle puts it out. I have changed the low pressure sensor (head) but not the one on the cooler. Any pointers greatly received!
Have you had the sump off and looked at the pickup pipe. If the oil pump has been off, did you prime it before refitting (plug the pickup with vaseline, and fill the pump with oil). If it's been dry for a long time, you could have the same problem. As for the setup, I'd definitely take it to a rolling road, to avoid wrecking what should be a pretty trick engine. If it's pinking at part throttle though, try disconnecting the vac advance (and plug the vac hose). Part throttle advance is all that the vac advance does. Heavy to Full throttle advance is done by the internal weights in the dizzy.
Not had the sump off, so will have a look. Oil pump has not been off. Took the engine out of a wrecked Mk1 racer about 8/9 years ago and has been in storage since. Obviously the oil has been changed but it would make sense that the pick up could be blocked. Sump has a outlet (currently plugged) which I assume was for a external cooler. Heard about blocking the vac advance before, but not tried it yet. Off to the garage to give it a go. I will however heed your advice and get it set up properly. Any recommendations of where to go in Suffolk? Cheers
Well, thats much better! Timing reset to spot on and vac plugged = no pinking! Idle is rubbish, but I can put up with that for now.
Spoke too soon.. Still pinks at high revs. I will get the oil problem sorted and get it set up properly.
Maybe worth venturing across the border to Dave Walker at Emerald in Watton. He's worked on slick'50 vw engines in the past.
I'd be fixing the oil problem first, tbh. If it's pinking at high revs and wide throttle, that suggests it might be running out of fuel. Could also be the dizzy is worn, and advancing too far.
The slick 50 engines I've seen dont take a lot of advance, 24 degree's.. over that and they rattle like a gud 'un. Idle will always be totally shat.
Ah, Mr Hillclimber, I just got this spec for the Slick 50 motors that you sent to a friend of mine; The general spec is... Ported inlet & exhaust manifolds, ported head on 40.5mm inlets/35mm exhaust valves (though some have been done on 41mm inlets), 11.5:1 c.r. If standard type cast pistons (KS) have been used they can (do) break up around the ring lands over time (too much c.r, rpm, weakened crown combination) if the piston has been heavily skimmed (the normal practise) to reduce the bowl size to raise the c.r . Standard crank & rods are normally used and are more than up to the job at this power & rpm level. I spoke to my local 'tune up' guy who bawked at the C.R and said I would never stop it pinking and couldnt see how it would run properly on pump gas. Brian Randall is round the corner from me, and their tag was on the original rocker cover. However when I spoke to them they were less than helpful, so may give this Dave guy in Watton a call. Dizzy is from a 60K engine and seems fine... If it is running out of fuel will the 16v WUR set up correctly cure this? I have the vacum on the side of the WUR plugged at the mo.
Nice of the original tuner to help out... Some are very wary of high c.r on pump fuel, but it can work with the right combination of bits. There are sometimes no hard and fast rules tho... I run just shy of 13:1 c.r on my own 8v on pump fuel with 32 degree's advance on the standard GTi dizzy. It'll take 34 with no pinking at all but makes less power, it will however pink on 32 with 95 octane fuel but has never been a problem on 97/98. My customer 8v wont take more than 27 degrees on a 12:1 c.r... both engines run a tight squish band, my engine runs a 318 degree cam and the customer engine (used to) run a 304.. so you can see how things can be effected subject to spec. The customer engine was an ex slick 50 unit and when on the original k-jet it would'nt take more than 26 degrees on an 11.7 c.r and the 304 cam, still with a tight squish. You should be able to get away with 26 on your engine but only on the road. When we originally set up the customer engine it would'nt take more than 24 degrees on the rollers due to the air temp, out on the road nugging up the timing resulted in much better performance and no pinking at 27 degrees. Start on a lower setting (24 degree's) and work upwards from there. Also, look at things to keep intake and combustion temps managable.... a heat shield between the two manifolds will reduce radiated heat, water temp needs to be kept down to around 75 degree's, and use a cooler running plug.. a 7 grade NGK is the norm on a plenum spec engine, an 8 grade on bigger power open induction engines. Hope than helps a bit.
