HELP! Can't do compression test on 76 Ford 351w
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=34774
Printed Date: October-08-2024 at 6:36am
Topic: HELP! Can't do compression test on 76 Ford 351w
Posted By: sberard5
Subject: HELP! Can't do compression test on 76 Ford 351w
Date Posted: October-14-2014 at 12:30pm
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I recently picked up a 76 Ski Nautique as a winter project. It has a Ford 351w and it is removed from the boat for stringer repairs. I am trying to do a compression test on the motor to see if I can get a year or two out of it before tearing down and have run into a problem. Problem is: I cannot get the engine to spin over fast enough to do a test. It doesn't seem to spin as freely as it should. Unsure of when the last time the motor ran but it was winterized when stored. Here is what I have done so far: Marvel mystery oil in the cylinders as well as some 10w30 Installed new starter Removed belts Marked and removed distributer Changed engine oil and filter (old oil was thick and black and sludgy) Primed oil pump - Thats where I stopped. Using a drill and a 5/16" socket and extension, I attempted to prime the oil pump in the LH direction same direction as the crank pulley. I verified it is the correct direction. I am just barely able to get oil to a few of the rockers but the drill slows down and stops. Too much resistance. Not sure where to go from here. Has anyone run into this on an engine that has sat a while. I figured with fresh oil and filter and primed pump I would get the engine to spin freely. I am baffled. Did notice that the compression was higher after doing all of this work but motor still spins slowly. Please Help. Best way to get ahold of me is my email sberard@myottmail.com or PM me. thanks in advance |
Replies:
Posted By: GottaSki
Date Posted: October-14-2014 at 1:06pm
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Are all the spark plugs out? What sort of battery are you using? Is your new starter the correct rotation? Your front pulleys should be spinning ccw. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: sberard5
Date Posted: October-14-2014 at 1:55pm
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Spark plugs are out, carburator removed and intake wide open Battery is out of my other boat. Deep cell marine 500 Cold Cranking Amps, 625 Marine Cranking amps. Starter seems to be correct rotation, front pulleys spinning ccw. Also note, I have removed the transmission as well........ |
Posted By: TRBenj
Date Posted: October-14-2014 at 2:02pm
| Sounds like a battery problem, possibly exacerbated by corroded and/or undersized cables. |
Posted By: sberard5
Date Posted: October-14-2014 at 2:35pm
| Engine is out of the boat. Using battery and jumper cables. Does turn over with the spark plugs in but struggles a little. |
Posted By: Orlando76
Date Posted: October-14-2014 at 2:40pm
| I'd lose the jumper cables. |
Posted By: GottaSki
Date Posted: October-14-2014 at 4:16pm
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I concur, jumper cables are not helping. A Deep cell 500AH battery is crap even when new, they are made for electric fish motors and outboards. Take a real starting battery out of your truck and spin it. ------------- "There is nothing, absolutely nothing, half so much worthwhile as messing around with boats...simply messing." River Rat to Mole |
Posted By: sberard5
Date Posted: October-14-2014 at 6:58pm
| Thanks for your advice. Problem is connecting my truck battery with side post terminals to the engine with the loop style battery cables. That is why I was using jumper cables. I'll see what I can come up with tomorrow. Any other hints greatly appreciated |
Posted By: sberard5
Date Posted: October-16-2014 at 1:08pm
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UPDATE! Took your advice and took battery out of my 06 GMC pickup. Using battery cables and a disconnect switch to make/break starter connection. Hooked everything up and tried. Turns over much faster now. Now onto the compression test. Squirted about 1-2 tablespoons into each cylinder prior to doing test. Here are my results. Note: Engine removed from boat so these are cold test numbers. 1-130 5-125 2-120 6-150 3-130 7-120 4-130 8-145 From what I have read these numbers look good. Anything I should be concerned about? Thanks again guys for your help. Much appreciated. |
Posted By: phatsat67
Date Posted: October-16-2014 at 1:17pm
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Looks good as long as you have good oil pressure. Cold on a manual gauge it should pump up to at least 20 psi spinning with the plugs out. The 240 hp Ford doesn't make enough power to hurt itself so as long as it has been somewhat maintained they are very robust with little issues and great reliability. ------------- |
Posted By: sberard5
Date Posted: October-16-2014 at 1:46pm
| Great thanks. I will continue on. Did find that the pump seal on the engine water pump is leaking. I take it they aren't rebuildable anymore? Easier to replace? |
Posted By: Gary S
Date Posted: October-16-2014 at 5:11pm
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Block circulation pump replace,raw water pump rebuild ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: sberard5
Date Posted: October-16-2014 at 11:53pm
| Excellent. I am on it. Thanks |
Posted By: 8122pbrainard
Date Posted: November-06-2014 at 10:02pm
Steve, You never mentioned if your leak is in the circ pump or the RWP. Which one is leaking? ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Gary S wrote: