Oil pumps

Previously wrote:

I bought a 1960 99 to restore and decided to start it to get an idea of what didn't work or might need doing before stripping. It started fairly easily and there were no nasty noises. However, after a couple of minutes smoke started coming out of the exhausts and oil was coming out of the Crankcase Breather at the rate of about a drip a second.

I stripped the engine expecting to find something big like broken/siezed rings but found nothing obvious. I did discover that a 6 Start Oil Pump Worm was fitted and it also has a pressure feed to the Rockers.

It is a 1960 Engine and it has the "Scrolled" type Rocker spindles so should not have either of the above. In the past I have read on the Forum that these modifications can cause the problem I am experiencing.

I can change the Rocker feed back to "mist" feed but am unsure about what I need to do about the Oil Pump. Can I just change the Worn Drive back to a 3 Start or do I also need to change the Pump?

Hello John A 1960 Dominator 99 will be happy with a 3 start system , AS the 6 start can over oil your engine give you more problems than its worth ? My 650 as a 3 start system too and it happy with it ? as long as you have a good oil pump every thing will be OK , Yours Anna J Dixon

Hi Michael,

here is a previous thread you might like, the 6 start oil pump gear is covered about 1/2 way down. Lots ofexcellentinfo:

http://www.nortonownersclub.org/noc-chat/technical2-heavy-twins-forum/215957733#100851704

You can type in keywords in the search box on the upper right corner of the webpage so search for topics also, I use that feature all the time.

All the best,

Skip Brolund

There are a number of combinations. Mixing them up in a bad way is not recommended. Although about use in G80CS machines, this has some useful pictures:http://www.centralcoastclassicmc.com/NortonOilPumps.htm

This has some background but is also not directly focussed on the 99. http://www.accessnorton.com/rocker-shafts-t10559.html

I have two 99 engines. A 1960 fitted to the bike and a spare 1959 in bits. When I acquired it the 1960 motor although untouched for over 30 years was very non-standard. I think any Norton today cannot be assumed to be standard. Check everything.

Cheers

Alan

Hi.

Perceived wisdom - as far as I'm aware - is that six start pump worms need six start crank worms. I think I'm correct in saying that the scrolled rocker spindles should be turned so the oil holes face the tappet ends when using 6 starts.The Dommi pumps had larger return gears in them and the smaller'feed' gears should be adequate. I've used six start gears in my 58 Dommi (with its original pump)and thrashed the nuts off it for years with no problems. The only problem I get is that itends up with a sump full of oil after three weeks if stood without use.The reason for fitting a six start pump, for me, was to increase the scavenge rate otherwise a three start works fine. It still blows oil out of the enginebreather when used hard but it did this with the 3 start set up. Reconditioning the pump helps and check that the brass plate on the end doesn't protrude past the edge of the pump/crankcase mating surface stopping it from seating properly. Mine did and correcting this madea bigger difference to scavenging and oil loss than anything else and stopped it blowing oil out of the oil tank breather!

Regards.

Ian.

Hi,

I hope the people concerned do not mind but here is the question again from Michael and the response from Dale Middlehurst:-

Hi Dale.

I posted what I thought was a simple question on the Forum but, although I have had several replies, nobody has actually answered the question.

I have bought a 1960 99 that is smoking from the exhausts and dripping oil out of the Breather. I expected to find something like seized/broken rings but can find nothing obviously wrong.

I have found that the Worm Drive on the Crankshaft is a 6 Start instead of a 3 Start. I want to change back to a 3 Start and the question is: Can I just change the Worm Drive on the Crankshaft to a 3 Start, or do I also need to change the drive on the Oil Pump?

Thanks.

Mick Pond.

Youâre quite right, the 6 start worm is causing your bike to over-oil ferociously, change back to a 3 start worm. You must fit a gear pair, one to the pump shaft and one to the crankâ?the engine will not turn over if you just change the crank worm, or will bend the pump shaft if you kick hard enough!

What may have been missed here is that Mr. Pond has said that his bike has pressure feed to scrolled rocker spindles. Plain rocker spindles are supposed to be used when pressure fed, otherwise you can have a large internal oil leak.

Oil pump gear sets should always be kept the same type, 6start or 3 start, changed in sets. Mixing them will not work as they have different angles machined into them.

I have thrown 6-start, or double-speed oil gears onto 3-start bikes with no problems, for practical touring I do not know if it offers any advantage.

So get some plain, late-type rocker spindles in your bike and it should have some oil control. Other than that like most Nortons if it sits for a while it will wet-sump and will blow oil out the crankcase breather on start up until oil scavenging catches up. If you simply drain the oil out of the crankcase and dump in back in the oil tank before you go for a ride it should behave perfectly....

Hi, I'm going to go out on the proverbial limb here.

I think you can just swap the three start drive worm and gear for the six start gears fitted at present.

I've examined three start and six start gears used by Norton's and the outside dimensions are the same, it's the angle of the teeth and the number of starts that are different.

I discovered this tid bit when I fitted a twin cylinder oil pump to my model 19s.

Regards,

Albert

hello guys well the engine its doing what it was built too do .when you leave you bike of a month or so it will breathe oil out of the breather ,but do not worrie about this ,its doing a good job of oiling all the parts inside your engine like like main bearing and the like , do not forget that a Norton twin is like the single with most of its parts are splash feed .on the twin the only parts that are presser fed are the large end shells and the rocker shafts on the return feed every thing else its splash fed . yours AJD

To summarise than: You can EITHER replace the scrolled rocker spindles for plain ones OR replace the 6 start oil pump gears with 3 start ones as a pair - i.e. both the crankshaft one and the oil pump one. DO NOT do both! Gordon.

For the idle Norton Owner: If you fit the 650/Atlas type oil tank where the engine breather goes to the oil separator tower in the tank, when you start after a spot of wet sumping, the oil goes into the oil tank rather that over the garage floor. Saves draining oil from the sump and putting it in the tank before starting. I know, I know, shouldn't do it, pure laziness, won't go to heaven...