I don´t think it is the supercharger/boost that brought this issues to the surface. Most likely you had an issue with the valves from before. For sure though running N/A and having 60Hp would most likely take longer to bring this issue to the surface.
Fix the heads and get back at it!
Alex
rubenski wrote:Oh boy.... my builder did a compression test yesterday... seems like there is a problem with the heads....
The engine was giving lots of backfires so thats why the compression test.
The cil 1 & 2 leaked bad.
Now the engine has to come out... again.....
He thinks the valve guides came loose.
Oh boy.... why did i ever put a blower on it....
Going to his shop on monday to start removing the engine and save labour costs....
For the level of power you are producing, you don´t need any special parts in order to last. If you have a healthy engine to start with, control over the AFR and timing, and a rev-limiter set at 5000-5500 rpm you are good to go.
My theory with the issues you had with the valves is that you have been using stock springs but running the engine at higher rpm that a stock engine. I think stock spring start floating the valve right around 5000rpm. I think you already had some damage from before adding the supercharger. HD springs are a must with anything bigger than the stock carb. The added breathing makes it way to easy to shoot past 45rpm:) The supercharger makes it even easier:)
I run HD springs and 5500 rpm limit on the street and raise the limit to 6000rpm at the track.
Are you running a stock crank or with counterweights? I run a stock one but balanced.
Alex
rubenski wrote:Yeah, verry frustrating.
But i have to keep in mind that when i build the engine 5000km ago, it was not build to be forced inducted But just normally aspirated...
Supercharged or turbo engines need other clearences and special parts to make 'em last....
there are coming hd springs on it like you say and I've ordered a cylinder head temperature gauge.
so then hopefully I got everything covered to get this blown engine to work.
If we still have problems when we build it all back, the blower will be ditched.
With the house now being build and stuff like that the funds are shrinking pretty fast... not to mention the wife and her complaints ...
The blower is going back on the shelf or maybe for sale. I dont know....
The heads got looked at and we found the problem and what caused it.
We had to back track how it occured:
The main problem was the valve springs. They appeared to be not strong enough.
What followed --> valves never closed since we mounted the small blower pulley.
So the heads always got to hot. Much to hot.
Since the blower pressure was bigger than the valve pressure there were opposite forces on the camshaft.
We measured it out yesterday and there is more than 0.5mm play. Over the whole cam front to back so all the bearings are worn out.
Meaning the cas has to be opened again..... pffffff
I've really had it now. Tired of messing with the blower and having no seat time.
I know the bearings are like 20 $ and my builder wont charge me for opening the case again. We'll do it together. And some stronger springs dont cost that much either but its just that i'm out of motivation.
So we gonna redo the case and just mount my dual carbs back on.
Like mentioned before i cant spend much on the veebub now since we got a big loan for the house we're building.
Maybe it goes on the shelf and in a few years i'll give it another try....
Look, why not just rebuild it and put the larger pulley back on. It worked well enough with that and that will allow you to enjoy it till you want to stuff around with more boost later on. There's nothing worse than having a car just sit there. Get it working and drive it. A set of bearings and valve springs are a small price to pay in some ways. At least the whole motor isn't torched.
where the springs go, to fit duals they cut down the OD of the guide boss...you can get some pretty decent single springs though, i use a special type of single spring on my webcam 86b.... only about £40 a set from stateside tuning too
could put it NA for a while to get some miles on it to enjoy it a bit again like you say, fixing it all the time is a drag! i know that!!
They were (with the case still closed and torqued) hanging loose in their seats.
So now we have to get somekind of bigger bearings and cut the cam.
Some new lifters too cause 6 out of 8 are showing wear because of the bad allignment of the cam.
Going to clear parts and case tommorow.
I'm having some tought on 1.25 ratio rockers. In combination with a engle w110.
Any toughts on that? To kind of make up for the loss of the blower for the meanwhile...
(Not expecting a world off difference like the blower but some more umpfff!)
