Distributor drive gears

minorv8 · Post by **minorv8** » Sun Dec 28, 2014 6:19 pm

What is the difference in pre SD1 vs. SD1 type distributor drive gear fitted on the camshaft (part nos 602159A vs. 614188A) ?

Oil groove, different skew on gears or something else ?

JP. · Post by **JP.** » Sun Dec 28, 2014 6:48 pm

Its the oil pump drive fitted to the gear. Pre SD1 can be modified to fit SD1.

minorv8 · Post by **minorv8** » Sun Dec 28, 2014 6:56 pm

I know the difference in oil pump drives on dizzy shaft. I am asking about the gear on camshaft.

mgbv8 · Post by **mgbv8** » Sun Dec 28, 2014 7:30 pm

As far as I know the gear on the cam is the same for all the Rover V8's

The only difference I know of is the length of the oil pump input shaft. So some engines need the wobbly extension on the dissy drive for the shorter pump drive.

DEVONMAN · Post by **DEVONMAN** » Sun Dec 28, 2014 10:05 pm

The pre SD1 has no oil feed facility and relies on oil splashed from the oil thrower disc on the crankshaft. On the sd1 and later engines the distributor drive cog is fed from the camshaft front bearing through the keyway and the cog has a groove in it to allow oil to flick onto the dizzy gear. The groove in the cog faces the camshaft.

Regards Denis

unstable load · Post by **unstable load** » Mon Dec 29, 2014 7:37 am

I have seen a nice mod to run an external oil feed to the dizzy drive gears, but it's buried somewhere in my hard drive, so will go hunting after work for it.

mgbv8 · Post by **mgbv8** » Mon Dec 29, 2014 6:55 pm

DEVONMAN wrote:The pre SD1 has no oil feed facility and relies on oil splashed from the oil thrower disc on the crankshaft. On the sd1 and later engines the distributor drive cog is fed from the camshaft front bearing through the keyway and the cog has a groove in it to allow oil to flick onto the dizzy gear. The groove in the cog faces the camshaft.

Regards Denis

The original V8 in my MGB (pre SD1) and 8:1 CR had the oil feed up the spacer groove from the camshaft bearing. Thats what it states in the MG manual as well. I thought the thrower ring was there to keep oil away from the front rope seal on the crank ?
I didint like the oil feed setup so I took the thick washer off the front of the cam and ground two grooves in it, in the shape of a cross. This allowed more oil to seep from the woodruff slot and get thrown out.

Pel

DEVONMAN · Post by **DEVONMAN** » Mon Dec 29, 2014 9:20 pm

Hi Pel,
I have several RV8 camshaft gears in my box of spares and some have a groove on one side and some have no groove. As far as I Know the ones without the groove come from the early engines which had a mechanical fuel pump which operated on a cam shaped spacer on the front of the camshaft. On electric fuel pump cars the cam was replaced by a spacer in combination with the grooved dizzy gear and provided better oil feed to the gears via the keyway space. Maybe Costello lead the way for this upgraded on the MGB's before the SD1 was born.
I agree that the oil thrower did minimise flooding of the rope seal but I think it also helped provided oil splash to the dizzy gears and mechanical fuel pump cam.

Regards Denis

minorv8 · Post by **minorv8** » Tue Dec 30, 2014 4:47 pm

My gear is smooth on both sides and dates back to 1974 or thereabout. It has a matching eccentric spacer for mechanical fuel pump. Local LR dealer did not have a new gear so I ordered a SD1 gear from Rimmers. The heads are also removed and I will take them to a cylinder head shop for evaluation and possible updates.

mgbv8 · Post by **mgbv8** » Tue Dec 30, 2014 6:18 pm

DEVONMAN wrote:Hi Pel,
I have several RV8 camshaft gears in my box of spares and some have a groove on one side and some have no groove. As far as I Know the ones without the groove come from the early engines which had a mechanical fuel pump which operated on a cam shaped spacer on the front of the camshaft. On electric fuel pump cars the cam was replaced by a spacer in combination with the grooved dizzy gear and provided better oil feed to the gears via the keyway space. Maybe Costello lead the way for this upgraded on the MGB's before the SD1 was born.
I agree that the oil thrower did minimise flooding of the rope seal but I think it also helped provided oil splash to the dizzy gears and mechanical fuel pump cam.

Regards Denis

Thats interesting you mention that Denis. My original had the groove and spare ones that I have bought from varying suppliers somestimes had a groove and sometimes didnt. I asked but was always told "some have it some dont" ? It was when I bought one without that I cut the grooves on the front washer

Pel

DEVONMAN · Post by **DEVONMAN** » Tue Dec 30, 2014 7:00 pm

The later ones have the groove and if you examine the groove size you will note that the surface outside the groove is a few thou lower than inside the groove. This feature is deliberate and the lowered surface allows the oil to escape more readily onto the cogs. Without the grooved item I would say the oil feed would be inadequate for any performance application resulting in premature wear of the gears. Your mod to the washer would of course be of some benefit.

In the case of the OP, it would appear he has bought a grooved gear but I think he will also need the matching spacer ( not the fuel pump cam type spacer) to get the correct oil flow.

Regards Denis

minorv8 · Post by **minorv8** » Wed Dec 31, 2014 7:00 am

I bought the gear, the matching spacer and even the dizzy gear...

DEVONMAN · Post by **DEVONMAN** » Wed Dec 31, 2014 9:43 am

minorv8 wrote:I bought the gear, the matching spacer and even the dizzy gear...

It would appear that you are sorted now.

Make sure the top of the Woodruff key is no higher than 30.15mm (1.2")when measured from the opposite side of the cam.

Good luck with the project.
Regards Denis