20 valve

Lamby · In rehab

RE: 20 valve

Lamby · In rehab

Starting on a sump shortly if anyone else wants one let me know asap !

Trekka273 · sponsor

Would having both sides of bearing casing with the oil groove mean that the crank can't float as well on the oil "film" on the bearing? I'm not sure, just a thought. I have always sort of thought that the manufacturers spend a lot of time and research designing these things, so there is a fair chance that they got it pretty close to right. Of course, if it works and helps keep your engine on the road, then it is a good thing.

LIAbillity · Rehab Dropout...

was thinking the same also ,
and i also heard it creates extra fiction ,

but on the other hand ,
the mains bearing load is spread across 2 bearings
that are larger than the big end bearing ,

Trekka273 · sponsor

We ran our silvertop for around 3 years and never, ever had a problem with the motor apart from a problem with the head work that we had done. Never once was there a drama with oil starvation, etc and we ran the standard sump.

LIAbillity · Rehab Dropout...

i've ran mine for 1 year ,with no dramas also
it's a stock silver with black top cams , thats all

not to sure what's going on with anthony's engines ,
he said to me the other day that he found most of them
spun the no. 2 big end bearing ,
not sure if these something there

what dramas did you have with the head work trekka ?
i've made a start on that black top i got from you finally ,

-- Edited by LIAbillity on Wednesday 2nd of December 2009 10:08:00 PM

Trekka273 · sponsor

With the silvertop that we ran, we got some head work done here in Melbourne which really helped open it up, the engine ran really, really well. Very driveabel with lots of power (for a 1600!!). The problem was that the guy who did the work, and charged us a fortune for doing it, didn't seat the valves as well as we would have liked. With the way he did them, it lead to the valve seats being a bit weak, which meant that after about 5 or 6 races we went to start the car the day after the Sea Lake Mallee Rally to get it off the trailer and it owuldn't start. Pushed it off the trailer and into the shed, did a compression test and 3 cylinders showed 0 psi, and the other showed around 20. When we stripped it down the valves weren't seating at all on the three cylinders, and only barely on the other cylinder. They had basically pulled through the valve seats. Was not impressed!! However, what was amazing was that the car finished the race without any problems whatsoever, finished top ten and ran beautifully. Obvioulsy once the engine cooled right down things were a bit different.

LIAbillity · Rehab Dropout...

so did old mate cut the seats to deep ,
or was it a different angle cut that allowed them to pull through ,

Trekka273 · sponsor

It was actually the angle he cut the seats at, it meant that they pulled through. When they selaed originally they sealed really well, but after some work they broke through and you could actually see a gap around the valves. Was not impressed....

LIAbillity · Rehab Dropout...

yeah i can see why you would be ,
it would have been ok for a drag racing car ,
not buggy ,

with the port work ,
did it lose its bottom end torque ,

Trekka273 · sponsor

No, we were actually really happy with the port work that we had done. It was a beautfiul engine to drive with. We also ran a 4-2-1 exhaust, and tried to keep the 2 pipes running for a reasonable length, which helps with bottom end.

Rusty Nutz · Forum Junkie

We also run a 4-2-1 exhaust. And did similar things with trying to keep the 2 pipes running even and for as long as posible. Does work well.

Very intresting reading about your head work and valve seats.

LIAbillity · Rehab Dropout...

i do also , funny how things like that happen ,

why you interested all o0f a sudden Lowrance ! lol

Rusty Nutz · Forum Junkie

Well you know they say jeremy. 2 great minds think a like. Or something. haha
Hey us NSW kids have got to do something to try and keep up with you blokes. hahaha

LIAbillity · Rehab Dropout...

you just need a bigger disposable income mate , lol

i once spoke to a cly head guy in perth
who said he had a new valve seat cutter that
cut a 4 angle seat , which gave better power and so on ,

though im wondering how long would the seat's and valves last ?
especially in induro motor sport like offroad
its proberly really good for drag racing ,
ONLY cause your in the car for less time than it takes to go to the toilet , lol

the contact margin would be very small
are there aftermarket valves and seats around for the 20 valves ?

Trekka273 · sponsor

You can get oversized valves for the 20 vlave from the USA. I was looking at getting some when I had that blactop. They are 1mm oversize, which is as large as they can go to fit in the head. I cant remember the name of the company though...