37 Knuckle rebuild advice requested

[37el1000]

Hello to all, I am new here!!
I have just got my 37EL on the road for the first time in my ownership. It all looks nice and much was done before my ownership. I took it on trust when I bought it that the engine was good. Well it was - for 10 minutes and then the oil came gushing out from the top end and the primary case. It will now be rebuilt. So to cut to the chase, anyone here have any experience of know any contacts who I can keep in contact with to get this pre war Knuckle in good shape? It's hard to come by any pre 40's Knuckle info - they are differnt in some respects to later models - mostly in the oil system. Mine has been converted to have tin rocker covers (sensible). I am a competent mechanic and I don't think anything is broken (just worn or mis-timed). Any tricks or advice would be greatly received. The strip down starts next week. Be nice to keep in contact with interested or knowledgable people. Cheers!!! Tony.

[HarleyAlba]

Some pics are always helpful.
Members will be able to tell you exactly what you have and help with repairs.
Sounds like a nice rebuild project

[kevscrivener]

You won't be short of friends with a bike like that!

There are a couple in HDRCGB with Knucks, but by far your best resource would be somewhere like the FHP board;

FLATHEADPOWER.COM-TECH TALK • Index page

Not as chatty as we are, but some serious know-how on there.

I post as Kev UK on there but my scant knowledge is confined to Ironheads and 45's.

If you don't already own a copy of Bruce Palmer's excellent "How to Restore your Harley-Davidson" then get one. It won't tell you much about daily maintenence but as a guide to what part fits what year and if you're doing an engine rebuild it's the absolute bible.

[Tomo.T]

Got a possible source of parts and advice here :War Department - Harley Davidson Motorcycles & Spare Parts They specialise in Harleys from '36 I hope the advice is cheap, the parts certainly arent !

Good Luck !

[37el1000]

Hi HarleyAlba,

At this stage the bike is a good looking complete one. When it gets stripped I could take pics of the progress (or lack of it). I have never used forums or blogs before. Perhaps a blog might be a good idea to get a progress report going. For now, the oil comes out the rear rocker cover, blasts out the breather into the chaincase (and onto the floor) and also there is a trickle out the front exhaust port running down the OUTSIDE of the front header pipe. New valves and Hepolite pistons were provided when I bought the bike. I guess that is an indication of what work wasn't done by the previous owner. I think seals for the valve guides could be a good idea - just need to locate any (and modified guides of course. Cheers!! Tony

[kevscrivener]

Originally Posted by Tomo8717

Got a possible source of parts and advice here :War Department - Harley Davidson Motorcycles & Spare Parts They specialise in Harleys from '36 I hope the advice is cheap, the parts certainly arent !

Good Luck !

You don't get nothing for free from that one buddy.

Caveat emptor.

[kevscrivener]

Tony, a quick question.

Did you check the oil before firing her up, find it was low and topped it up?


All older Harleys (and some modern ones) are prone to wet sumping when stood. As you'll know this fills the crankcase with oil which then exits where it can get out easiest.

Just a thought.

[37el1000]

Thanks to all!! I'll be ok sourcing the obvious parts - and yes, I have seen some of the prices!! I have the Bruce Palmer III book and it depresses me as I know know that one or two washers are incorrect for a 37 Knuck. I am sure to get on top of it. I live in the UK and there are many good people - I'm sure, but I have been out of the circuit for many years and lost touch. I had a 42 WLC for 18 years and sold it cheap it was also a great relaible bike - which didn't leak.Cheers to all!! Tony.

[37el1000]

Thanks Kev, off to bed now. Yes, sump was drained before fist test ride and oil tank topped up. Ride lasted five minutes as one of the new plugs went bad - but no oil leaks present. Second test ride, (next day), bike ran great. Opened her up - I was out for ten minutes, got home - pleased as punch, looked down - and !!!! Oil slick. These bikes rely on a timed breather to create a vacuum to get the oil back down from the heads and then to blow air out of a breather and oil into the chaincase. Rocker boxes will be removed and timing cover opened for inspection, oil pump scavenge and check valve will be looked at. Top end oiling was a problem on the first ELs in 36, so for 37 (my year), a nipple was put into the front rocker cover so you could connect an airline in to unblock oil lines. This feature did not appear after 37 as things improved and Harley then later enclosed rocker gear to stop muck getting in. Cheers agian. Tony

[Tomo.T]

Tony, have a look at this from an American forum I'm on. Knucklehead oiling problems Apparently there have been problems with people fitting uprated S&S oil pumps on early Knucks, which then overwhelm the return system and flood the rockers. Various ideas on restricting rocker feed, including adjustment, see also topic #38

Hope this is more useful than my last post !