The design of the 170/125/160 conrod was quite different to the classic/QB rod, the 170 rod had a phosphor bronze shell bearing in the top half of the big end but had a cast aluminium big end cap machined to be the bearing, meaning that they didn't have the benefit of a bronze bearing surface!
All of the 170 series motors were designed to run on a 25:1 oil mix, if your still running the original rod I don't think it would hurt to change that to 20:1 as part of your insurance policy, & strip & check the big end clearances before starting straight after purchase.
Out of the 10 or so of the 170 series I've owned, half have had big end clearances over 5 thou, (easy to measure with Plasti Gauge) necessitating new rods & cranks, I still have a couple of new cranks, if anyone needs one.
Check the main bearings, as they are known to wear more than expected, I have some new ones of those as well
Here's pictures of 2 new, unused 170 rods, with & without bronze end caps!
Model 170
Moderators: John@sos, charlesp, Charles uk, RickUK, Petergalileo
- Charles uk
- Posts: 4954
- Joined: Wed Feb 27, 2008 4:38 pm
- Location: Maidenhead Berks UK
Re: Model 170
If you are planning to work a 170 hard, then this would be a very good investment!
- Charles uk
- Posts: 4954
- Joined: Wed Feb 27, 2008 4:38 pm
- Location: Maidenhead Berks UK
Re: Model 170
Only have bearings & cranks left, 2 crankshafts, & maybe 6 pairs of main bearings.
The 2 new rods are patterns in case I get orders for 10 more, but please bare in mind that £120 was the price 5 years ago, but I do have enough investment castings left for 10 more, there was a minimum order value for the wax moulds & the casting work.
The 2 new rods are patterns in case I get orders for 10 more, but please bare in mind that £120 was the price 5 years ago, but I do have enough investment castings left for 10 more, there was a minimum order value for the wax moulds & the casting work.
Make it idiot proof and someone will make a better idiot.