Engine and Transmission Tech

tips, technology, tools and techniques related to vehicle driveline components

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RDMG
Dave R
Northern Virginia
(107 posts)

Registered:
04/07/2016 08:29PM

Main British Car:
1979 MGB 4.6L Rover V8

Re: swapping a 3.5 for a 4.0 rover in a TR8
Posted by: RDMG
Date: October 13, 2018 12:35PM

I posted a new thread on gerotor-style front covers with some pics of the inside of the serpentine cover, have a look at those pics and you’ll see what I mean.

The Bosch/Thor style 4.0/4.6 covers won’t draw oil through the original pathway/pickup, even if you swap the tubes and pans to the older mid-block style.

There is a hole in the 4.0/4.6 gasket for the original pickup pathway, but the passageway is then blocked by the casting. In the 4.0/4.6 casting that side of the cover is the high-pressure side. If you were to drill out the casting and remove the original tube, you would have the flow reversed, with no pickup at all. If you drilled the casting and used the 4.0/4.6 pickup, you would be blowing oil back into the pan through the original pickup pathway.


LaVerne
LaVerne Downey

(13 posts)

Registered:
09/03/2018 08:24AM

Main British Car:


Re: swapping a 3.5 for a 4.0 rover in a TR8
Posted by: LaVerne
Date: October 13, 2018 05:20PM

IMG_0721a.JPG this is the location of the pickup on the 4.0 block Same as the 3.5


LaVerne
LaVerne Downey

(13 posts)

Registered:
09/03/2018 08:24AM

Main British Car:


Re: swapping a 3.5 for a 4.0 rover in a TR8
Posted by: LaVerne
Date: October 13, 2018 05:24PM

IMG_0718a (1).JPG And the 3.5 The only thing that may be an issue now is the 3.5 had a stud in one of the main caps for to secure the windage tray and pick up. Since I have the 4.0 in the TR8 now with the pan on I cannot see if that cap is drilled and tapped, but I would guess it is not


RDMG
Dave R
Northern Virginia
(107 posts)

Registered:
04/07/2016 08:29PM

Main British Car:
1979 MGB 4.6L Rover V8

Re: swapping a 3.5 for a 4.0 rover in a TR8
Posted by: RDMG
Date: October 13, 2018 07:09PM

The 4.0/4.6 block allows you to bolt the old style pickups onto it, yes, but the serpentine front cover does not draw oil through that passageway. It only draws oil from the bottom, where the 4.0 pickup was. As you have it set up now, your crank-driven oil pump in your 4.0 cover will not draw any oil. It will only suck air through the hole you removed the 4.0 pickup from.

Your 4.0 cover may be different from my 4.6 cover, but I doubt it. In your 4.0, was the original pickup location capped with a plate and gasket or otherwise plugged to maintain pressure or suction? If not, then you can conclude the passageway isn’t connected to the oil pump intake.


LaVerne
LaVerne Downey

(13 posts)

Registered:
09/03/2018 08:24AM

Main British Car:


Re: swapping a 3.5 for a 4.0 rover in a TR8
Posted by: LaVerne
Date: October 13, 2018 09:55PM

The picture above was from the 4.0 when I removed he pan..with the pick up tube as shown. When I pull the engine for the rebuild I will use the pick up assembly and windage tray from the 3.5. Shouldn't be any issue that I can see.


RDMG
Dave R
Northern Virginia
(107 posts)

Registered:
04/07/2016 08:29PM

Main British Car:
1979 MGB 4.6L Rover V8

Re: swapping a 3.5 for a 4.0 rover in a TR8
Posted by: RDMG
Date: October 13, 2018 11:14PM

That’s very interesting— I’d love to see a pic of the inside of the front cover if you ever have reason to remove it.

There must have been a switch in castings somewhere in the late 1990s, perhaps with the transition from GEMS to Bosch. I had assumed the last casing change was the transition from the “interim” covers with provisions for a distributor, but your oil pickup setup suggests there was at least one more change. There’s definitely no way my 2004 4.6 would draw oil through the block.


tr8todd
Todd Kishbach

(342 posts)

Registered:
12/04/2009 07:42AM

Main British Car:


Re: swapping a 3.5 for a 4.0 rover in a TR8
Posted by: tr8todd
Date: October 14, 2018 07:41AM

There are probably close to a thousand MGBV8s and TR8s in the states now running 4.0 and 4.6L engines with the TR8/SD1 front covers, oil pans, and oil pickups. There are very few running the serpentine cover. I'm pretty sure the later engines had different pickups. When I had the last 4.6L rebuilt, the machinist asked me what I was going to do about the oil pickup. I didn't give it much thought as I've had several 4.0 and 4.6 engines built in the past. The last 4.6 came out of a very late 2003 or maybe even a 2004 Disco II. You raise a good point Dave. I may be in big trouble, but it doesn't appear that Laverne is going to have any trouble. I have a few of the serpentine front covers from various years. I'm going to have to look closer at whats going on. I'm guessing I probably should have had the 2000 4.6L stashed in the garage rebuilt instead of the 2003. The 4.0 in my TR8 race car was one of the crate engines BMW dumped onto the market when they took over Land Rover from Ford. Since it was sold after the 4.0 stopped being produced, and was a universal replacement, I'd assume it should work with any 4.0 front cover. I know its been running with a TR8 pan, pickup, and front cover for many years now. Towards the end, the 4.0 wasn't available. You could only get the 4.6. Maybe thats when they made a change to what your talking about.



RDMG
Dave R
Northern Virginia
(107 posts)

Registered:
04/07/2016 08:29PM

Main British Car:
1979 MGB 4.6L Rover V8

Re: swapping a 3.5 for a 4.0 rover in a TR8
Posted by: RDMG
Date: October 14, 2018 09:35AM

Looking at Rimmer Bros, they offer a 4.0 timing cover for pre-1999, 1999-2002, then post-2002. Too bad there’s not an explanation of the differences. It looks like we’ve identified at least one of them.

Anyway, I think we’ve beaten this dead horse, sorry to LaVerne for flooding your thread with timing cover trivia!

Good luck with the swap, I’ll be very interested in more pics as you move along.

Dave


MGBV8
Carl Floyd
Kingsport, TN
(3496 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
79 MGB, Buick 215

authors avatar
Re: swapping a 3.5 for a 4.0 rover in a TR8
Posted by: MGBV8
Date: October 14, 2018 11:38AM

Quote:
There are probably close to a thousand MGBV8s and TR8s in the states now running 4.0 and 4.6L engines with the TR8/SD1 front covers, oil pans, and oil pickups.

Lets not leave out the the ones running a Buick timing cover.
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