How to identify a 4.6 Lt engine as High Compression?

[Thehappyidiot]

Hi all,
I'm looking at a few P38 RR this week- one is a 2000 model, another is a 2001, and a third is 2002.
I have seen mentioned on the forum that there are High and Low compression versions of the 4.6Lt engine.
Is there a quick/easy way to identify the HC engines from either engine numbers or other readily identifiable facts?
Also, I read on the forum that the later models/engines did not have a transmission dipstick - is there any way to check the state of the transmission fluid on these?
I will be having one or maybe two of these checked out by a LR specialist pre-purchase, but t would be good to know a bit more about what to look for before I go out 'shopping'..
Thanks in advance for your help.
Best regards
PeteB

[PhilipA]

It's next to the engine number between 2 and 3.
Low compression starts with an 8 , High compression starts with a 9.
Eg 9.35:1. ( to all trainspotters , .35 may not be EXACTLY correct )

Regards Philip A

[Hoges]

Welcome to the forum! The CR on virtually all P38s is the lower version 8.37:1 . there was a higher compression 9.37:1 released in Nth America.. some of the last 2002 engines landed here may have it fitted... (search the forum for more discussion on this)
The CR is stamped on the block along with the engine number between cylinders 3&5. There is no transmission dipstick on the "Thor" upgrade models released here from around mid-1999... i.e. all V.I.N. from XA410482 onwards.
Hope this helps

[PhilipA]

That's what I meant 3&5 . Who spotted the deliberate mistake?
Anyway the two middle cylinders on the LH bank.
Regards Philip A

[p38arover]

A pic of my P38A GEMS block. Note the CR and that it's a 48D block (Actually this is a very early block that has the extra but unused row of headbolt holes that were a hangover from the RR classic engines.)

https://www.aulro.com/afvb/images/imported/2015/02/221.jpg

[Scouse]

Most (if not all) 2001 will be high compression. 2002 will be.

[JBM770]

The engine number prefix is also different. Low comp is 55D and high comp in later D2s is 56D.

The ECU computers are also different.

James

[Thehappyidiot]

Thanks guys,
All very helpful in getting to grips with the steep learning curve which is becoming very apparent!
PeteB