ARP Stuff
Turbo Mini Forums

Hey chaps,

Was just searching for ARP bolts for the main caps and found these in the link below. Anyone had good/bad experiences with these ? I have been reading on the centre main cap theories for the past couple of days and seems that no one really agrees on an answer. I think the way that I'm going to go is just retain the original cap but use some bolts, presumably ARP. What are your thoughts ?

http://arp-bolts.com/kits/ARPkit-detail.php?RecordID=1229

While on the subject. I also noticed that SC components advertise the ARP bolts for the K1100 conversion. Would that be a good investment for the build or would the old studs do ?

Specs:
- +20 forged pistons & rods
- worked crankshaft by Force Racing
- K1100 head
- turbocharged
- CR approx. 8.6:1

Arp stuff is great quality, but overkill in most situations, I always use them for rod bolts, as 70 quid or whatever they are is good insurance against wiping an engine out,

Head bolts are nice but the std a plus stuff is well up to the job, the biggest advantage is the amps have a hex in the stud so you can wind the studs out and slide the head forwards if you have turbo clearance issues,

The mains bolts are totaly overkill, I'd onlybother on a full race engine with steel mains caps, better value is getting the billet swifttune mains dowels, 15 quid and they are loads better than the std ones which can losses over time.

To be honest I just ripped three of the std dowels as they stuck in the block and when I pulled them out they sort of distorted. So I would be buying the dowels.

But I don't understand why you said the main caps ARP studs are overkill. Isn't the centre main one of the most sensitive parts of the block ?

depends who you talk to,

some people are of the opinion that machining the centre main down and putting the strap on actually weakens it, wheather or not thats true the std bolts are pretty beefy. certaintly for a turbo lump where your not going to be spinning the engoine that high the std setup is fine.

Oh I see. I was thinking that the load was the major problem, not the engine speed.

Engine speed is what creates the load Engines that don't rev high see far less loading on the bottom end.

As for the ARP kit for the K head it's up to you really. I use standard studs for anything other than full race but the standard nuts foul the cams so you either have to machine some clearance in the cams or find new slimmer nuts anyway. Arp kit solves that issue at least.

I didnt see the K head reference, the head studs are a lot of money for what they are, but that will because its a short run and SC will be putting their mark up on also. std ones will be fine bt IIRC you will need to chop them down a bit, and source hardened washers.

another point with the Mains stud kit is normally the gearbox needs fettling to clear them as witht he extra legth of the nut and washer and any stud sticking out it will foul.

Thanks for the info guys