semi synthetic oil in a flathead
 

Any thoughts on running a synthetic blend oil in a flathead motor? i I put it in my stroker motor with a high volume oil pump when I built it and it seems to run good oil pressure . i did this because I have become a believer in its ability to lubricate in high heat situations. I bought a Goldwing motorcycle many years ago that would kick itself out of 5 gear every now and then after the oil got about 800 miles on a change. the bike only had about 2000 miles on it when this started. A friend told me to try changing it over to a synthetic oil over a few changes of a blend to allow the clutch to get used to it. It worked by the time I got three changes done to it, the problem went away. Honda tore down several of the bikes fixing a clearance issue the had with them. The bike has 60,000 on it now and has not done it in years. I have seen it used in gear boxes as well that had high failure rates and it solved a lot of issues there as well. So I am trying it in my flathead, any thoughts?? I am also wanting to put a filter system on it as well and would like to know more about what I need to do to do that?

Re: semi synthetic oil in a flathead
 

Re: semi synthetic oil in a flathead
 

Make sure you have a good drip pan under the engine after putting in synthetic or semi synthetic oil. Those old rope seals were never designed to hold something like that back. If you built the motor with all new modern type seals front and back, you could get away with it.

Re: semi synthetic oil in a flathead
 

Filters are good but I prefer to change the oil every 500 to 600 miles . Its cheap enough and it takes me Bout a year to get those miles .

Re: semi synthetic oil in a flathead
 

I offer no advise, but I remember when synthetics first came out all the experts, and the oil company's all screamed to never ever mix the two together. Now, its hard to find plain old oil at the store, its all a "blend"

Re: semi synthetic oil in a flathead
 

I parked my '38 on a carpet in the garage for over 30 years with no drips. It travelled through 17 States and a little bit of Canada in that time, all with full synthetic lubricants in the entire drive train. Your results may vary. Damn, I wish I hadn't sold it!

Re: semi synthetic oil in a flathead
 

The oil topic is a good one. I remember when I was a kid going with dad to the service station on a Saturday to get his work truck oil changed. It was always a big deal, those guys were cool, they had good jokes, I got to walk under the truck, watched them grease it, real old school place to what you see today.

I remember them always using Kendall, and I asked why one day. They said Kendall was the best oil for low rpm engines. That stuck with me, even to this day 35+ years later, I still believe Kendall is the best. I never can find it when I need it so I just use Mobil. It’s synthetic but our flathead doesn’t leak.

JB

Re: semi synthetic oil in a flathead
 

Ya I've used synthetic in my flatheads, no leaks.

I remember 25 years ago trying synthetic in my daily driver and all of a sudden it leaked like a sieve until I put regular oil back in it. They fixed that since then for sure.

Re: semi synthetic oil in a flathead
 

Back in the day 1964, there was a hardware store near me that sold re-refined oil for 10 cents a quart, the Quaker State was 29 cents.