centre main strap?
Turbo Mini Forums

hey, could anyone give me a breif description on what they are, what they do and what they look like?

Thanks. Chris

998 turbo

cant tell you much apart from that they support the crankshaft in high revs. They seem to be quite cheap too. No idea what they look like though :s
someone else will fill you in in due time i should think!

NO LONGER A <3 lover of BOLT-ON plastic <3 .... (and DOUBLE proud of it)

was about to reply but can see turbodave is also viewing, so i'll back off and leave it to the master lol

lol, its bloody 2am in australia, i didnt think it woz worth posting it untill a reasonable time over there!

998 turbo

Centre main strap is a fairly basic method of stiffening the centre main bearing housing. As standard, the centre main housing is not all that stiff and can tend to flex. This causes main bearing problems.

The centre main strap is quite simply a piece of steel approximately 1" square, with the length to suit the width of the main bearing cap. I have not got one to hand so I can't give you exact dimensions. To fit the strap, it is necessary to machine the standard cap flat so that the strap fits nicely on top of it. You then use longer bolts and samdwich the whole lot up together.

It is a cheap and easy mod that is well worth doing to be honest, especially as the strap itself is cheap to get hold of.

There are other more extreme methods of stiffening the centre main, but these get expensive very quickly, as I know from experience.

Mike - I thought I'd let someone else take charge of it!



And Tom has!!!



Here is a picture of one modified!



Originally, the centre cap looked like the outer two. Note it is machined flat.

Edited by TurboDave16V on 21st Apr, 2005.

Tom, Is that a Picture of McGyver in your avatar?

Well it was an easy question to answer, so I thought I'll do this one, but I'll leave the REALLY complicated ones to Dave.....LOL

Dave- Yeah its M(A?)cGyver......anyone that can beat the A team in making lethal weapons out of junk, and always "happens" to find a welder in a derelict barn gets my vote......

Edited by Tom Fenton on 21st Apr, 2005.

True enough! The A-team always needed something with an engine.
All he needed was his famous 'MacGyver Penknife' and that was it!

ur starting to sound like Patti and Selma from the simpsons now. I dont suppose you always smoke a laramie cigarette after each episode of maguyver? :)

NO LONGER A <3 lover of BOLT-ON plastic <3 .... (and DOUBLE proud of it)

Mmmmm that sweet Laramie taste....

lol dave..

Heres mine before...



and after...

Edited by Mike on 21st Apr, 2005.

Here's a picture of a centre main strap and a billet 4 bolt main cap http://www.turbo-mini.com/44648/58147.html

Phil.

WWW.TURBO-MINI.COM

Not sure what it is like in a 1275 block, but on a 998 block when the main cap is machined it removes the slot for the thrust bearing tab to locate into. We had an engine like this and the tab eventually broke off and fuc*$d the block and the crank. The thrust bearing needs to be fixed from rotating, we have done it by having dowles machined into the bearing and the block.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

Just to slow the download time a bit...

Wil. I also made a fool out of myself when milling my 998 centre main. I never had done a 998 before, so I just milled away in 1275 fashion.
What I did, was to modify the main strap itself.
Here's the pic:




Here's my1293

Edited by Vegard on 22nd Apr, 2005.

lol, sweet az, it all makes sence now!

Thanks again. Chris

998 turbo

the best point of a centre main strap is that the block can balance perfectly on it when your painting it

Team www.sheepspeed.com Racing

I may as well post a photo too

can you guess whos workshop this is in? look at the green paint on the engine stand?

Team www.sheepspeed.com Racing

Who knows?!?!?

Whoever it is is a to55er for painting their block green

Nope, it isn't mine :)

Guess I'm a tosser then :(

All in good faith mate!

Edited by iain on 22nd Apr, 2005.

No Problem

dave, how many gallons of that green paint do you use a year?

Team www.sheepspeed.com Racing

FO