allen screw instead of little end bolt

[Stephen Barker]

Hello All,
just fitting ht Allen screws to con rods.Do the allen screws need a washer under them.Using locktite as well

[steve davidson]

Hi Allen,

I've done little end bolts with locktite (red) and no locking tab with no ill-effect to date. Can't see why the same would not be true for allen heads but others might know more than me.

[Erich]

My engine was built by Pigsty with Austin rods and pistons. I recently discovered, after about 4000miles by the previous owner who had the engine built, four deep grooves. When it comes apart for sleeving, I'll know better what happened and will let everyone know. It does make me more a belt and suspenders guy.

Erich in Seattle

[Ian Williams]

Gudgeon pin has come loose by the sound of it.

[Ruairidh Dunford]

Stephen,

around 20 years ago it was difficult to get good quality little ends bolts and a number produced were faulty, resulting in the heads snapping off. At this time I used Allen bolts and Loctite instead, they were not long enough to accommodate a spring washer as well. These are still proving excellent service.

The little end bolts produced now are excellent however and I have fitted hundreds, using a spring washer and Loctite without issue.

My advice is to fit the correct little end bolt from a known A7 parts supplier and fit them, spotlessly clean, with a square section spring washer and Loctite. The bolts cost around £1.50 for four, I think.

[GK5268]

Stephen,

around 20 years ago it was difficult to get good quality little ends bolts and a number produced were faulty, resulting in the heads snapping off.  At this time I used Allen bolts and Loctite instead, they were not long enough to accommodate a spring washer as well. These are still proving excellent service.

The little end bolts produced now are excellent however and I have fitted hundreds, using a spring washer and Loctite without issue.

My advice is to fit the correct little end bolt from a known A7 parts supplier and fit them, spotlessly clean, with a square section spring washer and Loctite.  The bolts cost around £1.50 for four, I think.

I did the same, BUT be very careful with the use of Loctite, too much and you risk sticking the pin, I know...

[Erich]

Exactly, Ian, but why would the pin come loose unless the bolt sheared? Perhaps one of the ones Ruairidh mentioned as the engine was built in the early to mid 90s.

Erich in Seattle

[Robert Leigh]

My engine was built by Pigsty with Austin rods and pistons. I recently discovered, after about 4000miles by the previous owner who had the engine built, four deep grooves. When it comes apart for sleeving, I'll know better what happened and will let everyone know. It does make me more a belt and suspenders guy.

Erich in Seattle

I fitted HT little end bolts from one of our cherished suppliers, using square section spring washers and loctite. On next dismantling following comments about noise from my tame listener (Fenella) and after 20,000 hard miles I found the head of one bolt lying on the gauze. Careful examination of the conrod showed that it had cracked downwards from the pinch slot. I tested by cleaning and drying the rod after soaking in paraffin. When I test fitted the replacement bolt and tightened it, paraffin appeared from the crack. This is a simple and very worthwhile procedure if a bolt has lost its head.
Robert Leigh