Anonymous
01-21-2003, 11:15 PM
IrishWake
1. Compression Test on Ford 351
I just had a compression test done on my 1993 Ford 351 engine and would like to hear some feed back on the results.
Cylinders
1 125
2 122
3 125
4 133
5 130
6 122
7 128
8 124
What do these numbers tell you guys as to the health of the engine? Or compare to compression tests on your engines?
Regards
Randy
Date: 12:14 p.m. on 02-02-2001
Engineman
2. Re:Compression Test on Ford 351
Randy,
your engine looks good. If the numbers vary by 25% on any cylinder it is going bad. But to take a good compression all plugs must be out and the carb flaps must be wide open. Second step is to put some oil in the cylinder and do it all over again. Compare these numbers. That will show if any leaks are at the valves or at the rings.
Thanks for trying us for the engine. Didn't know that the e-mail from Randy was IrishWake. The engine business is changing and the manufacturers are trying to keep up. Hopefully my staf is up to speed but do not hesitate to ask for me.
Tim
Date: 12:20 p.m. on 02-02-2001
IrishWake
3. Re:Re:Compression Test on Ford 351
Tim I'm still trying to decide if it's time for a repower. Thanks for the info and I will be sure to contact you when I decide
Regards
Randy
Date: 12:24 p.m. on 02-02-2001
Leprechaun
premium member in standard member. 4. Re:Compression Test on Ford 351
Randy - Why are you considering repowering? The numbers look good. Probably better than mine would be. Are you burning excessive oil or are your performance numbers noticably lower than those posted in other threads here? You motor is good for 1500hrs minumum with no more than by-the-book maintenance. Better maintenance and not asking the engine to be a 300hp outboard will increase that number significantly.
And by the way - did you get the '87 Shamrock brochures? - I mailed them out Monday last. Rgds, Leprechaun
Date: 05:03 p.m. on 02-02-2001
Prior Engagement
premium member in standard member. 5. Re:Compression Test on Ford 351
Not to sound redundant, but I too believe your numbers look fine. Must be a Gremlin in there somewhere else other then the rings. Are you fouling a plug or something? You can buy a lot of oil for $6K.
Good luck.
--------------------------------------------------------------------------------
Fair seas and tight lines,
Mike N.
Date: 10:48 p.m. on 02-02-2001
IrishWake
6. Re:Re:Compression Test on Ford 351
Lep, Yes I got your brochures and scanned them, they turned out great. So if anyone wants a copy let me know, I scanned the brochures from 1985 and 1986.
Lep and Prior, the engine is a 1993 FWC, no oil use at all, no fouled plugs either.I was just trying to determine the health of the engine. My 26' is equipped with a half tower and full ising glass and a windlass and assorted chain, anchor and rope but it's not really geting the speed that you guys talk about.I was getting about 3900 to 4000 on the original 16x17 prop, original sea trial for the baot in 1988 says 4200. I reproped to a 16x16 and got about 4200 RPM's and also tried a 16x15 and got about 4350 RPM's but my speed is only about 21-22 mph at 3000 RPM's with 3 or 4 people aboard with the 16x15 prop. I'm going ahead with a complete tune up (plugs, timing, plug wires and dist. cap) now that I know that the engine is healthy, so I let you know.
P.S. Lep, I'm dropping those brochures back to you today, let me know if you want the scanned versions for your computer. Thanks a bunch!
Regards
Randy
Date: 12:52 p.m. on 02-03-2001
Leprechaun
premium member in standard member. 7. Re:Re:Re:Compression Test on Ford 351
I got the brochures back in fine fashion, but check your e-Mail for another matter.
I looked at your numbers and they seem O.K. - but I would go back to the 16-square prop to get back some mid-range grunt. Remember that 1988 sea-trial was with a light boat, fresh engine and who knows whatever other variable affecting it. I don't think your current speed with the 16x15 is all that bad too. When you get the Floscan in there - post the rpm/speed/gph results and then we'll know what's up. FYI - I only get 3700 WFO on my rig. Who really cares - I never run her that hard - cruise around 2850-2950 and at that speed, even with the a very wrong prop she'll last a long, long time. Rgds, Leprechaun
Date: 06:20 p.m. on 02-09-2001
1. Compression Test on Ford 351
I just had a compression test done on my 1993 Ford 351 engine and would like to hear some feed back on the results.
Cylinders
1 125
2 122
3 125
4 133
5 130
6 122
7 128
8 124
What do these numbers tell you guys as to the health of the engine? Or compare to compression tests on your engines?
Regards
Randy
Date: 12:14 p.m. on 02-02-2001
Engineman
2. Re:Compression Test on Ford 351
Randy,
your engine looks good. If the numbers vary by 25% on any cylinder it is going bad. But to take a good compression all plugs must be out and the carb flaps must be wide open. Second step is to put some oil in the cylinder and do it all over again. Compare these numbers. That will show if any leaks are at the valves or at the rings.
Thanks for trying us for the engine. Didn't know that the e-mail from Randy was IrishWake. The engine business is changing and the manufacturers are trying to keep up. Hopefully my staf is up to speed but do not hesitate to ask for me.
Tim
Date: 12:20 p.m. on 02-02-2001
IrishWake
3. Re:Re:Compression Test on Ford 351
Tim I'm still trying to decide if it's time for a repower. Thanks for the info and I will be sure to contact you when I decide
Regards
Randy
Date: 12:24 p.m. on 02-02-2001
Leprechaun
premium member in standard member. 4. Re:Compression Test on Ford 351
Randy - Why are you considering repowering? The numbers look good. Probably better than mine would be. Are you burning excessive oil or are your performance numbers noticably lower than those posted in other threads here? You motor is good for 1500hrs minumum with no more than by-the-book maintenance. Better maintenance and not asking the engine to be a 300hp outboard will increase that number significantly.
And by the way - did you get the '87 Shamrock brochures? - I mailed them out Monday last. Rgds, Leprechaun
Date: 05:03 p.m. on 02-02-2001
Prior Engagement
premium member in standard member. 5. Re:Compression Test on Ford 351
Not to sound redundant, but I too believe your numbers look fine. Must be a Gremlin in there somewhere else other then the rings. Are you fouling a plug or something? You can buy a lot of oil for $6K.
Good luck.
--------------------------------------------------------------------------------
Fair seas and tight lines,
Mike N.
Date: 10:48 p.m. on 02-02-2001
IrishWake
6. Re:Re:Compression Test on Ford 351
Lep, Yes I got your brochures and scanned them, they turned out great. So if anyone wants a copy let me know, I scanned the brochures from 1985 and 1986.
Lep and Prior, the engine is a 1993 FWC, no oil use at all, no fouled plugs either.I was just trying to determine the health of the engine. My 26' is equipped with a half tower and full ising glass and a windlass and assorted chain, anchor and rope but it's not really geting the speed that you guys talk about.I was getting about 3900 to 4000 on the original 16x17 prop, original sea trial for the baot in 1988 says 4200. I reproped to a 16x16 and got about 4200 RPM's and also tried a 16x15 and got about 4350 RPM's but my speed is only about 21-22 mph at 3000 RPM's with 3 or 4 people aboard with the 16x15 prop. I'm going ahead with a complete tune up (plugs, timing, plug wires and dist. cap) now that I know that the engine is healthy, so I let you know.
P.S. Lep, I'm dropping those brochures back to you today, let me know if you want the scanned versions for your computer. Thanks a bunch!
Regards
Randy
Date: 12:52 p.m. on 02-03-2001
Leprechaun
premium member in standard member. 7. Re:Re:Re:Compression Test on Ford 351
I got the brochures back in fine fashion, but check your e-Mail for another matter.
I looked at your numbers and they seem O.K. - but I would go back to the 16-square prop to get back some mid-range grunt. Remember that 1988 sea-trial was with a light boat, fresh engine and who knows whatever other variable affecting it. I don't think your current speed with the 16x15 is all that bad too. When you get the Floscan in there - post the rpm/speed/gph results and then we'll know what's up. FYI - I only get 3700 WFO on my rig. Who really cares - I never run her that hard - cruise around 2850-2950 and at that speed, even with the a very wrong prop she'll last a long, long time. Rgds, Leprechaun
Date: 06:20 p.m. on 02-09-2001