1071s Main Bearing Cap

[Fanfaniracing]

Hi all.

I have here in my Workshop a 1071s engine with Mainbearing Caps i never seen bevore on a S Engine.
They were like the ones i have on my 998 Cooper engine, they were fixed with Screws and not with Bolts and Nuts like i knew them on 1275s engines.

The Number on the Block (over the Waterpump) is the same as on the Caps so i guess they belong together...

Anyone has experiance with that?

Thanks for reply

Fabian

[251 ENG]

All the early 1071 blocks have bolts to hold the main bearing caps

Just make sure you have the original correct bolts and not the 998/ 1300 type which will fit but do not locate the caps correctly .

[carbon]

Part number for these bolts was AEG156, don't think they are currently available so don't lose the ones you have...

This thread may be of interest : http://forum.minicooper.org/archive/ind ... -8462.html

[Vegard]

Good idea:

http://www.swiftune.com/Product/353/arp ... entre.aspx

[carbon]

I agree with Vegard that ARP studs should be a more robust option than 50 year old bolts. However be aware that the raised shank on the early S mains bolts is a slightly smaller diameter than the raised shank on the standard S mains studs. This raised shank is what located the main bearing caps accurately and needs to be a very close fit.

I don't think there are S mains studs available with the exactly the right size for these early blocks. Might be possible to get the S studs machined down to suit the earlier block, possibly others on this forum have done this?

[Fanfaniracing]

Hey Guys thank you for your reply!

I remarked also that the "Screws" ar a little bit conic where they meet the Block.

Will post a Pic of these tomorrow.

I think i willy-nilly must go for modded ARP Bolts as on top i will install the Arden Head.

If anyone has done this before i would much apreciate if he would parting his knowledge...

Here are this Caps and Screws i talking about:

[Vegard]

Whatever you do, lock tabs on the mains is absolutely forbidden!!!

[Fanfaniracing]

Vegard dont worry, i have allready the ARPs here

Here are the Bolts from near:

[carbon]

If that's the bolt you had with the engine than I am pretty sure it's not the original AEG156 type.

You need to check if the mains cap is being given positive location by the bolts. Easily checked, assemble cap without crank or shells with both bolts in pace but not tight. If the cap moves sideways more than a thou or so when you apply light pressure it is not located properly.

Hope this makes sense.

[scott6058]

My money bet it won't work. But I'm not a betting person.
Same problem, measured equal lengths on all my bolts may satisify my needs.
I was also told to leave the lock tabs out for they also allow torque miss figures old or new
Wish Mark would give some advice for he knows 1071's.
Scott

[Spider]

It appears that these blocks with the bolts on the Main Bearing Caps don't have a hollow dowel for location, so do they just rely on the bolt for that?

[Fanfaniracing]

No, there were no dowel's for locating.

Anyone has an idea if ARP Bolts fit?

[ricardo]

My 1275 block had studs and no locating dowels too. I'm interested to know if ARP studs will fit and clear the 3 sync 333 box with hardened washers behind the nuts.

[251 ENG]

No they won,t . they will hit gearbox case

[ricardo]

Ok, thanks Simon.

[Spider]

No they won,t . they will hit gearbox case

Is it that the studs are too long, the spot facings to high or both?

[251 ENG]

End studs are too long , shorten by 0.170" in lathe , re-chamfer threads and fit without washers

[newtune]

End studs are too long , shorten by 0.170" in lathe , re-chamfer threads and fit without washers

hang on i'll make it fit !