40 replies to this topic

[Dog]

Cheers John.

And thanks all, panic over

[lewis]

did you go to mra minis in the end?

[Dog]

lol, That was only suggested tonight mate, they'll be closed at this time of night.

and No, I won't go to them first, I'll try the nuts and bolts place down the road from me first.

[lewis]

oh ok, lol silly me

tell me how it goes in the end, im in a similar situation

[Dog]

No worries - should find out tomorrow - if my engine will fit in the Smart car that is...

[Dan]

used stainless capheads on most of my engine.

Not on anything important I hope. Good luck with that.

[Turbo Nick]

just block to gearbox, timing cover, alternator mount, outside the transfer case (unf ones). didn't have any UNC ones at the time else i'd have done the ones in the wok too (apart from the 2 i leave out). ARP's on the big ends and head...

but please do enlighten me as to why its such a bad idea.

[Dan]

Stainless is brittle and nowhere near as strong as the HT that you may be replacing with it. There are many grades of stainless but getting anything imperial in the better grades is very tricky and the stronger they are the less stainless they become generally. Chrome is a really bad ingredient to make anything strong out of. Personally I wouldn't do the gearbox, transfer case or clutch cover in stainless.

[alexcrosse]

ive got the same as mine, any bolts will do *thumbs up* stronger than 1/4 anyday.

I was confused when my bolts were loose too

[Bluemini]

I'm with Dan, stainless is too soft for anything that might be under a bit of extra strain.

[Turbo Nick]

well i've had no issues for the past few years running a fair amout of power (stress?) neither has my mate who's running just shy of 200lb/ft aswell.

the std block>box bolts are softer than an 80 year olds pecker!

[Jammy]

Moving away from the soft metals discussion for a moment. I've always had a mini that leaks from the back of the engine, at the gearbox/engine gasket. Will tapping the holes out help to solve this?!

[Turbo Nick]

doubtful, fitting the gasket properly would though.

[Jammy]

Well, with three engines, one has had that sealant type gasket, and the other two have had the paper type gaskets, all installed properly (I'm not sure how you'd mess that up ), and all leaked!

[Ethel]

Probably too late to err a little caution but....

Just because it's beeen drilled and retapped don't assume it is UNF (but chances are it is). I'd try carefully threading a bolt or 2 in to establish what thread has been used mate would be more available, so you never know.

Regarding Stainless, a 5/16" A2 grade stainless fastener will be about as strong as the original 1/4" fastener - but depending on the amount of thread engaged the improved strength of the threading in the block may be main factor.

Last time this came up DK suggested a chromate plate high tensile fastener would be the strongest option. That makes sense to me - a flanged hex head and well greased threads would seem the best way to ensure even torque and that they'll come back out when you want them to.

Squeezing the gearbox to block joint a little harder might help to stop a leak but a careful look at and dressing of the mating faces along with a fresh gasket on a squeeky clean joint would make success more likely - torque it up as you would a head gasket too, from the centre working out.