Mk1 with 9:1 compression

(PhilW) #1

Today I looked at a '60 MK1 and the compression ratio was 9:1 stamped on the ID plate and on the engine (matching #'s). I thought it odd to have that high a compression in a MK1 sedan. Did they make many 9:1’s on the production line or was this a special order?



I don’t know if production numbers of different compression ratios were recorded, but Mk1/Mk2 books say “(3.4L) compression ratios remained at 8:1 standard but the options were 7:1 and 9:1”
So not exactly a special order but an option.

(Art Ford) #3

Years ago I had a mk1 parts car with 9:1. It used “flat top” pistons. The librarians on the forum mostly ridiculed it but the hands on people knew I was right. Back in the 70s some people used to refer to those pistons as D type but I have no idea if that is correct.

(Piotr) #4

As I know - thre were no 1960 Mk1’s. It’s production ended in 1959. Maybe it’s Mk2 ?
Factory manual shows this in compression ratio subject:

(peter balls) #5

Yes Art, 120 parts books listed 9.1 “competition” pistons, I obtained a set in late `67.
These were machined with “stepped” top rings, They were/are flat top like the 7.1
but , of course, with a higher crown.
Peter B

(PhilW) #6

Here in some states, the car is identified as the year it was sold. This one was titled in 1960. I had 2 140’s that were built in 1954 but titled over here in 1955. When asked what year they were I said '55.