'86 FInj. Pistons
 

Hi,

I am down under in Australia. Way back in the '70's we had British Leyland doing mainly CKD assembly. Due to the distances and conditions here most of the British models were undersized and underpowered. The engineers here designed a vehicle coded the P76. It came out in two versions. One with a 6 cylinder and the other with a V8 based on the aluminum Buick that Land Rover has used for decades. The bore was identical to the 3.5l motor at 89mm but the stroke was increased to 89mm as well, giving a capacity of 4.4l. The Deck height was increased to allow the extra stroke. Heads and timing cover are interchangeable with the 3.5l version. To maintain a CR of around 8.5:1 the piston was given a deeper dish. Due to the higher octane rating of LPG, I want to increase the CR. The shallower dish in the 3.5l motor pistons will achieve this, giving me that extra efficiency and power. The original pistons have the standard ring groove of around 2.0mm. I have a set of oversize pistons from another P76 motor which have been replaced with shallower dished pistons(probably from a Range Rover motor). These also have the standard ring groove of 2.0mm. Everything looks easy so far, doesn't it? A few years ago, I stripped down an '86 fuel injected Range Rover and kept the standard bore pistons to build another 4.4l motor at some time. When I went the brand new rings to the pistons, they didn't fit. On first glance the pistons appear identical except for the different dish. Skirt length, gudgeon pin -identical.
The ring groove and thickness are different. Standard rings do not fit. The pistons I want to use have a ring groove of only 1.6mm. When I ordered stock bore replacement rings I have highlighted that there was a difference between the pistons. I made the assumption that the original P76 pistons were not standard to the Range Rover. Apparently the pistons I want to use (from a Range Rover) are not standard to the Range Rover motor. The different blocks are not an issue, but these weird pistons are.

Did Land Rover change the piston design for fuel injection in '86? Did Land Rover use this design at any time?

I have stumbled across forum posts: some where some when: suggesting that pistons from a 4 cylinder Volvo motor are good for boosting the compression on a standard 3.5l. Do those pistons have the 1.6mm ring groove?

Any help and advice will be greatly appreciated.

Bruce

have you tried some place like TOTAL SEAL PISTON RINGS , they literally have thousand of rings.

We did get any of those 4.4 blocks in the states, but if you have an extra one laying around

Thanks for the supplier - I have sent them an email requesting a quote.

I have a spare block which has been over-bored by 0.020' but needs doing again. The crankshaft has been machined down by 0.010' but needs a lot of work as well.
I have heard that the Buick 300 cid heads bolt straight on.

Freight would make it prohibitive though wouldn't it?

Most of the online catalogs only go back to 1987. You'd probably need a paper catalog or one on microfiche to see if things changed around 1986.

Though looking at turner's website, it looks like things changed in 1976:

Pre-1976: P5B,P6, MGB V8, Range Rover Classic >1976 STD Ring set 1970 - 176 - V8 Tuner
Post-1976: Std ring set 3.5 - V8 Tuner

Here is some other good info, it shows both the 1.6 and 2.0 rings:

http://www.grantpistonrings.com/_catalog_pdfs/rover.pdf

I tried matching up to the Buick engines these Rover V8's were born from, but it looks like they only came with 5/64" (2.0mm) rings:

http://www.grantpistonrings.com/_Cat...OTORS%20().pdf

Total Seal sent me two part numbers they said would fit. In the next sentence they stated that they do not sell outside of the US. When I contacted their Australian dealer, I was quoted $250AU. The rings I bought from Rimmers in the UK charged $100 AU.

We call it the 'Australia Tax' down here.

Grant Piston Rings contacted me and offered two parts -

C1504.000 3.500 bore 1/16 x 1/16 x 3/16 - Radial wall= 3.81mm x 3.81mm x 4.51mm AND
C1928.000 3.500 bore 1/16 x 1/16 x 3/16 - Radial wall= 3.81mm x 4.06mm x 4.51mm.


The original rings have the 4.06mm Radial wall with an internal chamfer. I have asked for a total price for C1928.000


Thank you both for your help so far. I will let you know how I go when I get them in a couple of weeks time.


Bruce

Thanks for getting back, if you ever need something shipped drop me a line i would be glad to forword it to you.

E

I would like to take you up on that forwarding offer.
Total Seal dist. quoted 'Conventional set $268.50inc· Gapless set $368.50inc' plus local freight of $16.45'.
Grant Piston Rings passed me off to their Aussie Dist.- probably the same deal.
These prices are in $Au, so I am looking at $375 of your dollars.
Pls let me know how we go about it.

send me a pm with all the information