18V blocks and main bolts

I'm going to be building an 18V motor and I would prefer to use studs rather than main bolts, is the process to simply recess the main caps to gain the correct clearance?

Opinions???

Steve,

Since you're asking for opinions, I'll offer mine. I think you're in search of a cure for which there's no known disease... :D The main caps on 18V engines are robust and I'm not aware of any problems with main cap shift or main bearing failure other than from insufficient lubrication. The main cap bolts are sturdy and, when torqued to the specified 90 ft-lbs., seem to never present problems. Perhaps that's why the design was changed from the early 5-main engines that did use studs instead of bolts...

Dick

Steve, I agree with both Dick and Hap. The 18v cap is much stronger than previous caps. This caused the switch to bolts and no washers. These bolts are called "place head bolts" IIRC and are designed to promote torque retention. They are good quality parts and I use them in all my builds. I think the torque spec is 75, not 90 as Dick indicated. Using ARP bolts with higher torque will tend to distort the main bores. A 1/2" NF thread high tensile bolt has torque capability a lot higher that 75 so using ARP bolts,IMO of course, is a waste of $$$ in this application.:)-D

Right you are, Dave, and thanks for correcting me. Correct torque for main caps is 70-75 ft-lbs.

Dick

I only torque to factory specs with the ARP bolts, there alot of thier fastner they give too high of torque on, flywheels bolt being other. One should know ARP, by no means are MGB experts if they were they would sell the right freaking bolt for the 18V rods. With that being said, nothing wrong with factory main bolts, or good quality grade 8 bolts, which the factory bolts are.

The deal with the ARP studs, going into a 18V block is they are too short, so there would not be enough thread ot even engage the nut, the 18V main caps are taller. In the case of the block Bubba inherited with GT race car, those dumbasses had dropped 3/8 dial pjns in the stud thread hole to space the stud upward, that was not entirely stupid idea, but not checking to see if the oil pan would fit was, just one of the booby traps you run into follow someone else's lead, you somewhat assume they know what they are doing. When this happen to me, nobody and I mean nobody seemed to know about, Dave Headley or David Anton didn't, nope I was ginea pig on this one, maybe I should have ask the ARP fastner expert on this forum, he would've known, or he would called Kent Prather or Joe Huffaker and then told me :devil:

Thanks guys... I already have the ARP bolts for an 18V. As Hap noted, maybe I was under the sway of the fantasy that studs are superior to bolts.

Nothing beats a fantasy like half a dozen experts telling you "politely" to pull your head out of your... well you know what I mean.

Thanks for the feed back.

Steve

I looked at late blocks for my original Twin Cam conversion, but was concerned about core shift which seems prevalent in later engines (I broke through the cylinder wall on one late block, done as a test at around 84 mm.). I did look at the main cap issue but concluded that there hadn't been any problems with the early caps and studs, so went with an 18GB block. Is that incorrect? Have you guys been seeing main cap issues with the 'studded' blocks?

Bill,

I'm not aware of any particular problems with the earlier studded blocks, but, as Hap points out, the main caps on the 18V engines are more robust, and IIRC I think the main saddle webbing is also beefier on the 18V blocks. So no particular problem with the studded blocks but, given the choice, I'd go with the 18V...

Dick

I've seen some later 18V block with alot oof core shift, but it's not constant thing, I wrote a thread about on the MG forum a few yesrs back. I think at that point in time, at the factory they let more questionable stuff pass thru quailty control, due to a shortage in funds. You can tell it pretty easy just look in the core plug bore (with the core plugs removed) if the inner shelfs are way of center, there ya go, you got core shift.