I was reading this old thread;

http://www.914world.com/bbs2/index.php?sho...amp;hl=ARP+8740

about a batch of h-beam rods with ARP 8740 rod bolts.

I wanted to get feedback from anyone who used these rods on a hi-performance type 4 application and what were the results?

Are the ARP 8740 bolts described for use in this 'batch' H rod a 5/16" or 3/8"?

What kind of RPMs were run and how did the 8740 bolts hold up?

Here is the ARP description of the two bolt materials;

quote:

8740 CHROME MOLY: Until the development of today’s modern
alloys chrome moly was popularly considered a high strength material.
Now viewed as only moderate strength, 8740 chrome moly is seen as a
good tough steel, with adequate fatigue properties for most racing applications,
but only if the threads are rolled after heat treatment, as is the
standard ARP production practice. Typically chrome moly is classified
as a quench and temper steel, that can be heat treated to deliver tensile
strengths between 180,000 and 210,000 psi.

ARP2000: An exclusive, hybrid-alloy developed to deliver superior
strength and better fatigue properties. While 8740 and ARP2000 share
similar characteristics—ARP2000 is capable of achieving clamp loads
in the 215,000-220,000 psi range. ARP2000 is used widely in short track
and drag racing as an up-grade from 8740 chrome moly in both steel
and aluminum rods. Stress corrosion and hydrogen embrittlement are
typically not a problem, providing care is taken during installation.

LN Engineering has some real world feedback on his site...he did some testing.

Rich

Thanks mr towle, I looked on LN website and did not find much info on the performance of rod bolts. Though they seem to lean their use preference to the ARP 2000 bolts for their rods.

I thought for certain there would be at least a few guys on here, who bought some of the 50 Raby H-Beam sets sold with the ARP 8740 bolts ..... and could share their experience.

What RPM were they used at, what pistons were used and their weight, how many miles thus far .......... basically how the ARP 8740 bolts are holding up.

As I recall Jake pulled the plug on that deal! No rods ever made it into folks hands. (or at least mine)

Thanks for posting! That explains the lack of feedback

I guess I will redirect my question to the ARP 8750 bolts themselves. Has anyone used them on any H-Beam rods?

..........ALWAYS use the best parts that your budget will allow.ARP 2000 bolts would be the choise for a high performance engine. Only use aftermarket rods with shuffle pins.,Stock rods use the rod BOLT as the shuffle pin., if you remove them, replace with new../and with new nuts.....Rod bolts are a part , in witch only the best quality should be used. All the installation techniques should be adheared to, most especially the streach measurements (at room temperature).

Looks like I decided to go with ARP 2000 5/16" 220,000 PSI bolts.

AND all money was returned to every single purchaser. I didn't even deposit the checks, I sent them back in the envelopes they ame to us in. That was almost 7 years ago!

The manufacturers who were going to make those components did not do as they agreed and were not willing to offer what they had promised. They didn't get a single dollar.

8740 bolts are fine for sane RPM levels and outputs. They are fine unless you miss shifts or have heavy rod beams, wrist pins and pistons with revs less than 6500 RPM.

The ARP 2000 is a better bolt and what most all our rods use, or a custom aged ARP 2000 unit, which is what we use in the M96 engines. We also use these in EP/FP 914 race engines, one of which has 2.5 years of 8,500 RPM service under it's belt.

But the bolt is only as good as the rod that it couples.. Rods that lack strength allow bolts to loosen, then the bolt fails.

Most people reading this don't have an application with the ability to outperform an ARP 2000 bolt-