Centre main Cap/strap
Turbo Mini Forums

Below is a picture of my centre main cap which has been machined for a strap. The problem is that, unlike 1275 caps, when the cap is machined the locating slot for the thrusts is machined off. It is apparently common practice to just use the thrusts as they are and let them float around a bit, but I have done this in the past and wrecked an engine.

The problem is that the sharp edges (circled) can knock the locating tab off the thrust washer causing it to spin round, this obviously wrecks the block and cap.

As a result of this I now have my thrusts and caps dowled as shown. worth doing IMO.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

Looks a good solution, when I built a 1098 based engine for my road car some years ago, I got my mate to machine a small recess in the strap itself for the thrust washer tab to locate in, worked a treat. I also got him to machine a flat on top of the strap, so I could still use the original style locktabs too.

What you're supposed to to on 998 maincaps, is to machine a 1" groove in the middle, Not remove the top completely as per 1275s.

I did the same as you once, and thought I'd really fucked the engine...

The BEST solution to this problem is:





This has worked perfectly for me.
If you need it, I've got a steel piece perfect for the job. It only needs machining. You can have this for free + postage. Please contact me.

Edited by Vegard on 7th Dec, 2007.

""What you're supposed to to on 998 maincaps, is to machine a 1" groove in the middle, Not remove the top completely as per 998.""

^^ I thought that

Your strap is much wider than mine, meaning you can machine in a locating groove.

The dowells seem to work fine though, cheers for the offer though.

Wil

Edited by wil_h on 20th Feb, 2006.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

Yes, I made my own strap out of some fancy expensive steel. I had it ofcourse made with my own measurements....

the engineer that did my strap (1275) has done it totally different to what ive seen before, but i forgot to take piccy before i fitted engine to block. he removed the minimal of material from the cap i mean minimal! made some spacers for inbetween the strap plus cap then counter sunk the bolts. does this make sence, he assures me this will be stronger and its how he does it on his own midget engines, so im going to give it a go and see how it holds up. ill try and get a piccy through the side of the gearbox for you.

no longer a series, but still 1.3 turbo.

ive seen this advertised:

http://www.7ent.com/images2/FOR052.JPG

imo its utter bollocks. all it does is create the need for longer bolts.

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

Nice and bling with all that engraving!!!!

A guy in Norway has got such a setup. The car is not running yet however!

hope hes not using their centre main strap! LOL

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

You don't need the strap on a turbo engine anyway! It doesn't rev that high.

Also, I cannot see what that cap makes any worse..

fair enough you might not need a cap on a turbo motor, my point was that that cap does sweet FA!

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

that cap does do something. it does a similar thing to the flat version. its increasing the strength of the centre main.

how? the cap over the bearings completely unsupported...

Edited by joeybaby83 on 8th Mar, 2006.

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

This is how Simon has done mine:



Muts nuts.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Just like mine However, I did file the grooves. That took bloody ages.

It must be good if it meets Vegards' approval!

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

No no no your overlooking the easyest way!

All i do is file the slot to locate them into the block insted of the cap and stick them in the otherway up, nice and easy!

That was actually not that stupid.. Ha, great. I know for next time :)

dont be silly, that would be far too easy!

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"