Compression A Code 289

Hi V'ger No one cylinder should be less than 75% of the highest reading, therefore your lowest compression could be as little as 138.75 psi... However, to see if the rings/bores are bad, you would need to get them (I assume it's in the shop...) to perform an 'oil check' also - they squirt about a teaspoon of oil, about 40 weight, into the bad cylinder via the spark plug hole, towards the back of the piston, then wait a few minutes, and recheck. If the reading goes up, you will need new rings or a rebore, otherwise, I think it's just normal wear and tear.

You didn't say which cylinder is affected. I had a similar problem on my

289 A code, on the 8th cylinder. I had readings between 155 and 170 psi on cylinders 1-7, and 80 on the 8th. I performed the 'oil check' on the 8th, and the pressure went up to 130 psi (just under the 75% limit). So I thought rings on the 8th need changind, maybe broken rings... Wrong - when I finally stripped the engine this Xmas, I found the piston pin had slipped, and was wearing a groove into the bore. Also, probably because of the added stresses caused by the friction of piston pin against cylinder wall, the conn rod big ends have worn into the crankshaft, and rendered it useless! (I think also the wrong bearings were used when the last owners had it rebuilt!)

It may help if you buy a book by Tom Monroe - "How to build Small Block Ford Engines" - printed by HP books, ISBN 0-912656-89-1. This is where I get the majority of my info (along with the Haynes Manual), and goes into detail about engine troubleshooting, and diagnostics, as well as info on rebuilding and parts interchange between engines....

Good luck with what you decide to do. Personally, I'd leave it unless it's your daily driver and you have nothing else (and you have a lot of money!!!)

Let us know how you get on

Kevin

67 Money Pit conv. 289 4V - 7T03A123001

"V'ger" a écrit dans le message de news: snipped-for-privacy@4ax.com...

First, thanks for a very informative input. It's not in the shop at this time. I won't have a lot of money until I sell my 66 Fastback, my

91 TransAM GTA, and my 87 Escort. In this case it's "probably" fair wear and tear. It's the original vin engine, and it runs strong and idles smooth. No bad oil showing on the sparkplugs. I just joined a car club - C(lassic) A(merican) M(uscle) C(ars) which has just been formed, and I'm just beginning to get to know the other members. We also have a local Mustang Club (Independent) which I plan to join as well. Just bought a Chiltons Repair Manual. Will get the one you recommended (Think I saw it listed in Mustangs Plus Catalog but didn't know which books were good or not). What is the Hanes Manual? Any other recommendations gladly accepted. The car is in about a mid 3 category, and there is work to be done, but I needed to know about the engine problem for budget purposes.

I know a lot but most of what I know is that there is much I don't know, and much to learn. I didn't grow up with cars. Instead I got to travel the world with my folks.

So, my BIG thanks.

Dave

V'ger

1965 Fastback 2+2 Burgundy w/ Black A Code 4 spd 1966 Fastback 2+2 White w/Red C Code Auto

Glad to be of help! The Haynes Manual is a series of automotive manuals, much like the Chilton's. Usually has some good tidbits of info in it, but don't rely on it 100%! I rebuilt a Beetle engine using only a Haynes, and didn't realise I had to check (and change) the fuel filter diaphragm - I therefore ended up with fuel pissing into the sump, and subsequently seized the engine good and proper!

The ISBN n° for the Haynes is 0 85696 357 7 (and it's book #36048). It gives 'Standard' and Metric sizes, which is handy for me, as I'm in Europe, and 'Standard' tools are hard to come by...

Anyway, good luck with the engine!

Kevin

PS If the Chilton book gives the re-bore sizes for the 289 A code, could you let me have them, as I need to check to see which rebore has already been performed. (I forgot to buy one while I was in Florida last year!)

Thanks!

"V'ger" a écrit dans le message de news: snipped-for-privacy@4ax.com...

I'll check the Chiltons and fir off whatever I can find on re-bores.... might take a day or two for the email to reach you in Europe if I have enough stamps; ) I lived in Scotland for two years and in the Azores Islands for two years. Loved both. But, I do enjoy the California sunshine; )

Dave

V'ger

1965 Fastback 2+2 Burgundy w/ Black A Code 4 spd 1966 Fastback 2+2 White w/Red C Code Auto

Excuse me for butting in. What is it exactly you are looking for?

CobraJet

I was just trying to get some info on a low compression cyl situation. Elmo is looking for information regarding re-bore sizes.

V'ger

1965 Fastback 2+2 Burgundy w/ Black A Code 4 spd 1966 Fastback 2+2 White w/Red C Code Auto

Re-bore sizes? You need to know the stock bore and available overbore piston diameters?

CobraJet

V'ger

1965 Fastback 2+2 Burgundy w/ Black A Code 4 spd 1966 Fastback 2+2 White w/Red C Code Auto