Before there was ARP we used to use Mopar Performance 340 rod bolts and as i remember they were interchangeable. Before ARP listed bolts for the slant 6 we used to use their 340 bolts and I don't remember there was any machining required.

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If you didn't drive it there, it's not a street car.

Same here Seymour. They drop in.

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Hyper_pak

If that's the case, I wonder why they chose to use the GM rod bolt as an answer instead of using the 340 bolt that they also were making at the time since it seems to work better?

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There's no such thing as too much cam....only not enough engine!

That is an excellent question!
Inquiring minds want to know.

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Hyper_pak

Mike always used ARP kits for the 340 too. They were actually cheaper than the Slant 6 set. Plus, after you did 3 sets of rods you had a 4th set for free.

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Official Cookie and Mater Tormentor.

Back in the early 80's before ARP was such a big name, there were several other options for premium race quality fasteners. B&B was one and so was SPS. Both offered bulk pricing that was cheaper than package prices. Milodon is a good option as well

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There's no such thing as too much cam....only not enough engine!

I ran SPS bolts in my SBC race engines back in the day. Never a bottom end issue in those old hobby stock engines. Is SPS still around?

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“Buy the ticket, take the ride.”
― Hunter S. Thompson

I likely will not put any ARP bolts in stock rods again. It would be my guess if we keep rpm's below 5500 or so the stock ones are fine.

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2 Mopars come with Spark plug tubes. One is a world class, racing machine. The other is a 426 CI. boat anchor!

12.70 @ 104.6

Back in my working days, I never specialized in fasteners to be able to say that is an expertise, however no matter what components one was responsible for, fasteners came in to the discussion, from time to time.

Concerning rod bolts, I remember that the shank (that is the section from the bolt under head to the threaded section) of the bolt was always a press fit into the rod end. The purpose of the press fit was to constrain the rod bolt, so it was held in place for ease of assembly and also to limit as much as possible bending of the rod bolt shank ( the area from the underhead to the start of the threads). The movement of the threaded bolt diameter area at the rod cap was controlled by the bolt torque (clamp load) and the basic strength of the bolt.

Making this comment as the press fit of the rod bolt into the rod is very critical. The tight fit basically makes the lever of the movement shorter. A rod bolt that 'drops in to the hole" will have a potential for movement that can put shear stress at the shank near the underhead of the rod bolt.

Rod bolts are among the most highly stress fasteners in an engine. The shorter one can make the bolt, buy constraining the shank, the more robust the bolt will be.

I would be leery of any rod bolt that "drops into the hole."

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Doo Ron Ron and the Duke of Earl are friends of mine.....
https://www.youtube.com/watch?v=uX8Nj8ABEI8

There are/were (2) different ARP rod bolt part #'s, 142-6001 & 142-6002, they have distinctly different head styles.

One is supposedly for cast crank rods and one for forged crank rods.

Now that this discussion is in process, I am wondering if Bob Dally's Bonneville Barracuda used these bolts in his 170s and caused 1-3 engine failures due to thrown rods and/or bearing failures. It is too bad that ARP did not do their homework on this.

Lou

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Home of Slant6-powered fun machines since 1988

Lou, Bob's Barracuda threw the little end if I remember correctly.
Number 1 or 2.
I have never seen that before.
Wish I had snapped a picture of it.

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Hyper_pak

Interesting. Never heard of that either. He had other bearing problems besides that time, and I know his oil pressure was low when I got there and it decreased after some dyno pulls.

Lou

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Home of Slant6-powered fun machines since 1988

Not a current thread, but I just checked a stock 318 rod bolt against a forged crank stock slant six rod bolt, and I cannot see any difference. I would think the ARP bolts for a 318 should work for the slant.

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Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Good Show Charrile, Probably also the 340/360 Bolts too?

I would *think* all of the LA Bolts are the same?

Greg

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http://www.youtube.com/hyperpack