AbeFM

iTrader: (3)

I've been on an EPIC journey to get main cap studs better than stock. I wasn't going to get any at all, but bid on some ARPs on a lark and actually won. It's going in a motor with a B.E. oil pump (VVT era), Carillo H-Beams, wiseco turbo's, so it'll be pretty built. Oh, and a MBSP.

There in lies the rub, literally. The ARP kit doesn't fit the MBSP. This motor has been out for, oh, 8 years or so, and what do the big engine builder smarty pants do? Cut the MBSP with a dremel, right where they are thickened for strength. They all trim the tray.

I wanted to go a more elegant route, so I told ARP about this. They ignored it. Told them again, and on the third try, this guy tries to help me out. They sent me some WAY undersized nuts and told me to turn down my studs. I didn't like the nuts, so I turned some washers, and even that wasnt enough so I turned the four worst nuts, too. After all's said and done... I just need washers that are half as thick. I wanted the material to be reasonable, so I asked the guy...

He recommended I get something at least that strong. Um, how do I find something like that, or should I just turn down another 4 washers and call it a day?

neogenesis2004

iTrader: (12)

How about trimming the MBSP like everyone else and then welding on supports to add back rigidity. Seems like the smartest, simplest route to me....

y8s

iTrader: (8)

got a photo of where they hit?

curly

iTrader: (25)

I'm pretty sure most hardware stores will have hardened washers, right along with their hardened bolts, nuts, lock washers, Allen screws, spacers, and kitchen sinks.

AbeFM

iTrader: (3)

THAT hardened? I don't have a good feel for how hard is that hard. Some of the materials people here actually know.
Do *I* have pictures. Silly man.



In the end it needs to lose about 1.5mm




I think you could get away with some very small cuts. What's irritating is that no one wants to fix it. Why sell a kit then have a pile of mods to do to it, unless it's a "hey guys, I messed around and came up with this. And I'm selling it much cheaper than anyone else because while I know it'll work it'll take some messing around with".

more pics at
ARP Stud & MBSP Interference - AbeFM's Photos

I should put more of the turned down nuts. Sense of scale: Washers need to be ~half sized.

AbeFM

iTrader: (3)

It's odd they have a bump on the sides of the thicker part, like it looks like it wants to just "fit" the cap. It's hard to imagine it going in for looks... But I'm not going to FEA the whole thing... :-)

SolarYellow510

Given that the MBSP is held together with a handful of spot welds, I reckon it has more to do with NVH than with holding your bottom end together against the stresses of high RPM and boost.

I would go ahead and grind the MBSP like everyone else, rather than screw with the best hardware you already bought.

Or design a real MB girdle that fits and get it CNCed from 1/2-in. plate.

AbeFM

iTrader: (3)

Ha. I like that last idea.

Turning the studs doesn't exactly give me wood. Messing with the nuts really bothers me.

Thinner washers are a no brainer. I won't be coming within 1-2 thread of the nut, though, so it won't be hurting the studs at all. Honestly is just bothers me that no one cares.

y8s

iTrader: (8)

grind the place where it hits.

then run a bead of weld where the layers join to make it strong.

neogenesis2004

iTrader: (12)

I agree with y8sipoo.

Grinding and welding reinforcement seem like the no brainer. It's cool to find clever solutions to problems Abe, but you are having a severe case of engineeroveranalyzitus.

olderguy

iTrader: (19)

McMaster sells hardened washers

Reverend Greg

iTrader: (3)

Find a machine shop with a surface grinder and have them grind your washers to thickness,get a hundred(costs the same as 4)and sell the rest.
-G-

AbeFM

iTrader: (3)

I'd think buying them. Maybe McMaster will just have ratings.

+1. Grinding AND welding is a pretty amazing idea
huh



Actually, turning the studs IS very easy. I'll look again at how much I'd have to cut.