Hi all,

A few of you may have noticed that I've changed my username a while back to match what I have just started to build.

The last engine in my car was a 2332cc turbo/intercooled engine but as i had issues with lifter and cam failures the engine was stripped and a few changes were going to be done to sort out these problems...

I wanted to run a lot more power, change the cam to make it rev, and have it all hold together. I'd reached the safe limits of an 8 dowel chromoly crank. Though i'd never broken a gland nut, the power levels want to run would only survive with a wedgemate or flanged crank, so i've upgraded to an 88mm flanged crank with a type4 center main.

So far today's progress saw me cleaning parts and measuring up. I've modified the oil galleries on the CB alloy case to support my radical dry sump oil system setup.

I sat the crank in the crankcase for the first time on a couple of number 2 main halves and machined up a front crankshaft seal arrangement. (Sorry no pics of that yet). The engine will be fully sealed and under vacuum when running.

Then I came accross my first issue. I recall watching the monster garage 9second vw build, and the engine seasure that happened due to oil flow issues to the number 1 main bearing. As flanged cranks are known to have some issues in this area due to the lack of end float washers, so i thought to start by checking out oil gallery alignment.

To my supprise it barely lined up at all. See the pics.

My thoughts are that I should I oval out the oil feed gallery in the bearing saddle so it lines up with the oil grouve in the bearing. Then I also think that widening the oil channel in the bearing so it lines up with the other side of the oil hole is the go, which will take 2 minutes on a lathe to do.

Anyone else seen a main bearing align so badly before? This is a Scat flanged type 1 main bearing...

Cheers,
Ian


[ Edited on 8-9-2007 by 2443TT ]

[ Edited on 8-9-2007 by 2443TT ]

It is common to have to open out the hole in the case to line up with the bearing.
A Dremel or small die grinder burr is a good way to do this.

It would be nice to see where the oil hole IN THE BEARING is because this is very important.
I like to have a straight shot from the case hole to the bearing hole in the bearing.
Widening the groove in the bearing is an option, BUT...

I would personally prefer to just unshroud the back of the bearing
in just the one spot
to prevent the added surface area exposed to pressure
from trying to lift the bearing away from the case tunnel.

Have that bearing coated in some form of moly or teflon
and then make sure the end float and clearance are adequate.
Those Scat bearings are not coated, like normal bearings so they need some help.

I would like to see 3 thou diameter clearance and 8 thou end float after coating.

Hey everyone,
I agree Dave,my new case was just as bad, also may want to open up the hole in the BMW bearing for the center main. There has been alot of talk over here about thrust bearing failures with the flanged cranks, have seen the conversion(RIMCO), they have been going to a thrust bearing in the center to get away from the heat caused by clutch heat being transfered to the bearing thrust surface. I look forward to hearing about your progress.
Mike

I attacked my case and bearings today with a dremel and lathe. Made a fair amount of progress all in all.

I started by solving my oil issue by enlarging and ovaling the oil feed hole a little.



While I was at it, i enlarged the oil return from the flywheel seal. This is to aid oil flow from behind the flange back to the sump. Some people have had issues with the main seal leaking or blowing out. This has been put down to two things.. Firstly was installing the main seal after the case 1/2's have been torqued up. The second was inadequite oil flow. This mod was developed and tested by Muffler Mike in the US.



After machining.



Here you can see the bearing, and how i've widened the oil channel in the back of it considerably. Still it wasnt wide enough to allow the hole in the crankcase to be completely uncovered. So in the second pic you can see i've used a die grinder to carefuly widen the area that is over the oil feed hole a little. These two mods should solve the problem.





Here we have the heart of my new engine. A Revmaster avaition 88mm flanged chromoly crank with 5.7" CB rods. I got as far as cleaning everything, plastigauging and installing the rods.




This is my front pully seal. I've modifed a standard sand seal a little, and use a diferent seal to make it all go together. The chromoly pulley hub had a rough finish on it, and was too large in diameter to fit inside the seal holder so that got machined down on the lathe and polished. Next I discovered that I needed a spacer, so i've chopped the hub out of an old alloy crank pully and made a spacer from it. Conventient because it has the slot for the keyway in it.




Thats all for the moment. I want to get the crank into the crankcase 1/2's mid next week but am still waiting on a custom grind camshaft from the US. I dont expect that to arrive for 2-4 weeks.

About the issue with flanged bearing failures, you will find that that failure mostly refers to type 4 flanged crankes that have a lot more reduced thrust area. Also most of these engines are very high output engines and require some serious clutch pressures, so if your foot is riding the clutch it heats up the thrust bearing pretty quickly.

I was planning to run a 4 puck and a kennedy stage 3, but have now switch to twin 200mm porsche clutches discs with a 1200lb pressure plate. That will make the flange crank a lot more streetable and hold 450rwhp as well.

Cheers,
Ian

[ Edited on 9-9-2007 by 2443TT ]

[ Edited on 9-9-2007 by 2443TT ]

450rwhp - just quietly.......

nice work ian. what are we looking at to stop this bad boy? 6 pots all round?

nick

Same brakes as you just bought actually (944 turbo), but the suspension and 1/2 the driveline is 1988 944 turbo as well. New chassis, IRS and Mcpherson strut suspension. Its going to be a busy next 6 months.

Nice work Ian,
I like the revmaster crank,same brand I bought,but mine is wedgemated 86 w/5.5 rods. Life would be alot simpler for everyone if the manufacturers of these parts would actually assemble a prototype and recheck the alignment of everything before going into production ,luckily the crank seems very good as compared to the case. Did you find any issues with the crank? Thanks , Mike

No the crank was good according to the machinists that balanced everything for me.

The case on the other hand... Apart from the oil holes not lining up, the flywheel end oil relief was rough as hell. It took a lot of patience with an end mill to clean it up. I then used an old piston and some fine valve grinding paste to re-surface it.

The oil pump home in the front of the case is machined too large too, which means i'd be having oil pressure and leaking around the pump housing back into the crank case issues if i were using a normal oil pump setup. Fortunatly Im not, and the oil return on the case side is drilled, tapped and plugged to stop oil flow in that passageway.

The sooner the scat killer cases are available again the better...

looking good ian

I know that the case that you are waiting for has not arrived yet, but what about the cam?

I'd love to see some more pics of the progress!

Sorry no progress on the engine. Though the Web 226 cam has arrived so i have everything I need to build it up now.

The chassis build is my main focus at the moment. Working on it stirs up a lot of dust in the workshop so its far from being clean enough to build an engine in at the moment. I am trying to limit my concurrent projects or it will all get out of hand. Also last weekend and this weekend were and will be spent wiring a porsche for a friend instead. Im still waiting on the 924 steering rack for my chassis to come from the UK. It should be here before next friday with any luck.