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MG Midget and Sprite Technical - Top end oiling kit for 1500

Looking at the kit that runs oil directly from the oil sender via external braided tubing to up under the valve cover to keep the top end "wetter". I do like keeping all those little parts sliding around in there but would like some feedback on this thing. Any experience good, bad, or ugly? Can the top run too dry in the 1500?
Thanks
Bob
Bob Ketcham

Bob,
have a look in the Archives as I don't think it's a universally popular idea

and at this John Twist video about 1500 engine with suggested improvement for top oil way - http://www.youtube.com/watch?v=uAgbcbxFD98
Nigel Atkins

Ive seen those ads on ebay... its a cool looking idea

Im not sure id do it though...my fear would be not being able to evacute the oil running down the push rod holes in a timly fashion and getting to much oil on top of the cly head

Im not sure if that is true /factual or not...just my gut feel

Prop
Prop and the Blackhole Midget

Does anybody know if Deborah Evans of Priestess Race Engines still contributes to this forum? She's been quiet of late, but (maybe a year ago?) I remember her writing about the perils of the 'conventional' external accessory oil feeder pipe for the 1500 Triumph engine which purports to improve oil flow to its cam. She strongly advised not to try and improve oil flow doing it that way. In fact, she stated that the kit made oil flow worse in the engine as a whole, because it created oil cavitation. One would have to search the BBS midget archives for exactly what she wrote. Her words certainly put me off the idea.
Andy Hock

Right, John Twist's observation is that yes, the external feed provides extra oil to the rocker shaft, but at the expense of the center main and #2 and #3 big ends.

He describes how to enlarge the gallery feeding those points, but it all makes me wonder if the top end is as much of a weak link as the center bottom. If one of those locations was going to fail, I think I'd prefer the top to go first.

-:G:-
Gryf Ketcherside

I have run my 1500 with and without the external oil feed to the head for a number of years and as Gryf says the bottom end of the engine needs to be protected more than the top so I don't have the feed fitted at present.The central oil gallery has enough to do without adding extra demands on it.

I didn't notice much difference with or without, but I suppose it is a long term wear thing, so there would be not much to notice in the short run.

I did fit "O" rings to the valve stems to prevent excess oil being sucked down them, so I don't know if that could have been an issue if I had not fitted the rings.
JB Anderson

Having just changed my bottom end shells I concur that wear is mainly there. And I am resigned to it now I can do it. However has anyone ever thought about a larger sump for more oil to be in the system before adding mods that take extra oil out of the sump and therefore away from the pump? If the amount of oil was increased but the oil level stayed the same at rest would that help with keeping the lower end oiled if the upper end oil was increased?

Just a thought.
Dave Squire (1500)

I would expect making sure the rocker bushes, if any, and rocker shaft were in top condition would benefit the top end with the standard feed.
David Billington

Why cant the push rod holes be reduced in size and slow down the flow to retain more oil on top of the head

Prop
Prop and the Blackhole Midget

I've just stumbled on these words of wisdom concerning the 1500 Triumph engine, from Deborah Evans:

====================================================
With regard to the oil feed to the rocker shaft assembly, then there are a number of companies that will sell you an external rocker feed kit. Unfortunately all these kits are fundamentally flawed as they come and lack adequate instructions as to their fitting.

EVERY kit I have seen uses a –3 hose with a banjo fitting to go into the oil gallery plug at the back of the head and a 1/8 NPTF fitting to screw into the main oil gallery beneath the distributor. A moment’s thought, given what I have said about oil feed to the centre main bearing, will show up just why this is a bad idea. By connecting the rocker feed in this way you will inevitably rob oil from the centre main, hence you will actually make your motor more likely to go pop! Additionally, with no restrictor, you will over-feed oil to the rockers causing problems with inlet valve stem oiling at low rpm (meaning your motor will both burn oil and be closer to causing detonation from the reduction in octane of the fuel/air charge!). Finally, merely fitting an external oil feed while the internal oilway to the cylinder head is active will cause cavitation in the oil galleries and all sorts of flow problems. By far the best way to fit an external rocker feed is to firstly block off the vertical oilways in the block and head (use a tap and an 8mm grub screw in both block and head) and to take the feed from the main gallery at the rear of the block (opposite number 3 main) via the 5/16” UNF oilway plug tapping. To do this you will need a –2 to –3 male-male adapter to screw into the side of the block.

======================================================

The above text is taken from here: http://triumphspitfire.rickbaines.com/weaknesses-of-triumphs-1500-engine/
Andy Hock

Dave,I believe there is enough oil in the system, the problem is it is not distributed very efficiently in the engine by bad design of oil ways, in particular the central gallery.
The rocker shaft doesn't have proper bearings, ie bushes, so not to have a proper oil feed to it is another mistake, but as said before I think the bottom end is more important.
JB Anderson

Right JB. So its back to make the bottom end galleries larger - I have some details somewhere which I think are Debs's from some thread somewhere - for when I rebuild the spare 1500 I have. That is what all the 1500 'improver guys' as well as Deb say is most important. Then with a little fettling; more power and reliability is possible on a quick road setup. (about 100HP at just under 6000 rpm). That is about 70 to 75 HP per ton; better than my modern.
Dave Squire (1500)

Thanks for the input, the youtube video that Nigel posted the link to above recommends opening the central gallery from 1/4 to 5/16 as it must service the center main and 2 crank bearings while the end galleries at 1/4 only do 1 main and 1 crank. Number 2 and 3 are where most failures occur in the 1500.
Bob
Bob Ketcham

Andy,
I've fitted one as recommended by Deb whilst refurbishing a friend's motor.

Thanks again for the help at the time Deb...

Bottom end galleries were opened up as per the recommendations and IIRC 8mm grub screws in the block and head to close of the gallery both sides of the head gasket. The -2 to -3 adapter was a challenge to find and I ended up buying a custom made pipe with a suitable fitting on the block end. I still have the kit pipe in the stock pile of good ideas if anyone wants it?

The mod does put a fair amount more oil to the top end but it flows way quite quickly and only time will tell if this lot actually helps....

Best of

MGmike


M McAndrew

This thread was discussed between 27/08/2013 and 29/08/2013

MG Midget and Sprite Technical index

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