40 replies to this topic

[Dog]

Hey all.

Started fitting my gearbox to my block tonight.
I managed to get some bolts off my 998....

I went to see if they fitted, and found that they are too thin They go into the box fine, but going into the block, no chance

Are 998 bolts smaller than the 1275 bolts?

If not, how do I know what size bolts I need? or is it a possabilty that my block "holes" have been enlarged to 5/16?

Cheers
Mart

Edit: The block is a 1275 overbored to 1380, and it s pre-A+

[advantage998]

Hmm sounds to me your block has had the threads tapped out to 5/16ths unf instead of the 1/4 unf originally found on all a/a+ engines.

[Big_Adam]

Aye, 5/16th is a trick to stop flex...or something.

Tis fine though.

[Dog]

Cool, glad that I have the 5/16 bolt holes
Just got to get some now

[Turbo Nick]

i never realised the holes had been enlarged dude, the chap i bought it from never mentioned it anyway.

I bought a selection pack from this chap anyway when i built my last engine, used stainless capheads on most of my engine.

http://stores.ebay.c...4QQftidZ2QQtZkm

[Big_Adam]

I said it before, good local bolt shops will become your friends when you find one.

Mine has an ex-BMC worker. Nice chap, shame about his hip though. Damn NHS being slow.

[Dog]

My local bolts shop was next door to where I used to work, so they are already my friends
Will take the block up and get them to double check the sizes, but for now, its stopped me in mid-flow of doing my engine

[Bluemini]

If you are going to get new ones, for ease of fitting/tightening, get cap head bolts. Trying to get a spanner or socket on the original bolts was a pain in the arse, so it will be even worse with bigger ones because they will have bigger treads. With cap head bolts you can use an allen key with a 'wobbly' head to get to the awkward ones.

[Dog]

Awesome, cheers Blue - just had the chap I got the block off say that too. Is there any kind of steel which is best to go for?

[Turbo Nick]

stainless

[Dog]

Will stainless be strong enough?

[mini93]

stainless is just a treatment i think (or at least depending)

when u get the bolts just them fr string anti corrosion ones, ask for torque setting aswell (if they know)

[Guess-Works.com]

Use HT steel cap heads....

[Dog]

Ta John. Was waiting for a reply from yourself

You got any in stock at all Mate?

[Guess-Works.com]

Nope, try MRA-Minis