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Proper compression numbers
Posted: Thu Jul 10, 2014 3:00 pm
by shaner
I was wondering if anyone can tell me the proper compression numbers for a 91 diesel delica.
I have done a search and have found a range from 300 to 450.
I just did a compression test on my van and this resulted in compression of 425-450 across all cylinders. Is this ok or to high?
Thank you
Re: Proper compression numbers
Posted: Thu Jul 10, 2014 10:25 pm
by thedjjack
sounds good to me... important is the range across cylinders which seems good....
Re: Proper compression numbers
Posted: Thu Jul 10, 2014 10:37 pm
by FalcoColumbarius
Go to the L300 Dedicated Category Reference Forum; look for L300 Shop Manual Downloads. In that thread you will find all the specifications for the 4D56T. In fact, in the 4D5 section (11B13) of the "4G7 & 4D5 Engine Manuals" there's a compression pressure check walk through. Hope this helps.
Falco.
Re: Proper compression numbers
Posted: Thu Jul 10, 2014 11:40 pm
by shaner
Thanks Falco.
I checked the other shop manual for the 4d56t engine but not the one you mentioned, thanks. It appears the proper compression is 3040 kpa or 440 psi so it seems that I am in the right range.
Just out of curiosity, do you know what the 6t means on the 4d56t number?
Re: Proper compression numbers
Posted: Fri Jul 11, 2014 10:59 pm
by FalcoColumbarius
The "T" refers to turbo and I believe that the "56" refers to the bore and stroke, but I'm not sure how ~ it could just be a code. There are a couple of diesels that fall under 4D5, one being the mighty Astron 4D56 and there is also the 4D55, which among other applications went into the Ford Ranger for a couple of years. Both these engines have the same bore but the stroke is greater in the 4D56. That's my thinking but what do I know ~ I'm a painter. 
Falco.