993turbo

Great info Mark.

Do you have the official information on the lift on the ROW S cams 80 - 83 and 84 - 86?

I can only find the duration figures in the WSM and Tech spec book.

Cheers.

tilac999

ROW '84 and '85 are the same or different? I'm confused.

Landseer

Here is what we think is an early Euro S piston (lifted from Gunar's thread)

993turbo

Many are confused.

If you see my post above, I list the engine numbers change overs, for both Auto and manual ROW S cars. This happened somewhere mid-84 model year.
The only difference is a slight change to the pistons.

993turbo

Landseer, this would be a tolerance 1, 97mm, 80 - 83 ROW S (and some 84 ROW S,up to the engine numbers I posted above)

Landseer

So, are you saying that if the pistons are installed in the correct orientation within the engines, that no EuroS cars theoretically are non-interference?

If not interference per se, are there operation conditions that would cause collision?

Like, as the belt breaks under load, engine RPM jumps and rips the cam belt across the DS bank at such an elevate speed that it accelerates the valves to float into the pistons?

Or carbon build-up can sum to greater than the gap distance?

Just trying to learn here. Why are we having the dialogue if the engines aren't interference? Isn't there some history of Euro belts breaking and valves bending? ( I'm glad that DougM posted the question / interesting / hope his valves aren't damaged, BTW)

dcrasta

Some 16v motors (non-interference) the belt breaks, you cry a little, and you can fix it ($..)

All 32v motors (Interference!!)' the belt breaks, you cry like a baby because you know this is pain , real pain. You 'can' fix it but prepare for valve damage, piston damage, real $$($$$$$$).

So - Don't break your cam belts! They only break from neglect or improper repair.

mark kibort

so, you have the two different pistons shown on this thread now. (thanks Glen)

euro 80-83 deep cuts
euro 84 to 85, shallow cuts

euro 80-83 non interference, because the valve pocket is near .5 deep! total lift of the cam is somewhere in the .4" range, and if you depressed a valve in the head of an assembled motor, you would see that the valve is pushed down .3" and it touches the piston, with euro 85 valve cuts. this means, if you have .2" of a deeper pocket, you have clearance up to .5" lift with no problems.
break the belt, nothing will happen.

mark kibort

when the belt breaks,the valves stops, or continue to spin at some out of orientation timing due to stripped teath on the belt, which is how it usually "breaks". the valves are going up and down and at .3" the would make contact on an 85 motor, on a 82 motor, they would would have to be pushed down .5" which is greater than the cam lift.

so, no interference in a euro 80-83 motor

mark kibort

same lift. devek posted the lift a long time ago. I have it written down or on my computer. ill look

lift is the same for both cams!

Tampa 928s

I just looked at my euro 85 82E 05721 does this mean a lower compression ratio?

mark kibort

80-83 is the lower compression ratio 10:1 vs the 10.5 or so for the euro 84-5

993turbo

82E 05721 is a 84' model year engine. If it was an 85' model year engine if would be an 82F xxxxx

84 = E
85 = F
86 = G

It always helps if you write the engine type as well. M28/ 21? or M28 / 22?

993turbo

the compression ratio is 10,0:1 for the engines in the 80 - 83 ROW (euro) S.

10,0:1 is also the compression ratio for the EARLY 84' model year ROW S (S2) with LH-jet. The change to the 10,4:1 pistons were at the following engine numbers ( as I wrote in my previous post )

M28/21 82E 00596
M28/22 82E 06114

the change to the new 10,4:1 pistons happened sometimes in the middle of the 84 (E) model year.

993turbo

I would be very happy if you managed to dig up the lift numbers. It saves me some measuring.