Wooldridge 22' Classic Spring Rehab and/or Repower

[bmunsell]

With all the nice weather we've been having I've gotten an early start on boat projects this year. All winter I've know that I faced a few more than normal projects this spring because by the end of last season the exhaust manifolds were leaking fumes and water fairly bad and making lots of extra noise, it was getting almost impossible to shift the 3 stage Kodiak jet into reverse without killing the motor and the main jet thrust bearing/seal was leaking.

So, so far I've pulled the drive shaft (this is motor forward boat), the exhaust manifolds, taken the jet apart and removed the main shaft, pulled up a big part of the floor boards and gotten the shift cable out to the boat. While I was at it I thought I might as well do the throttle cable, so I pulled it too.

With the exhaust manifolds removed the spark plugs are really easy to get at so I figured I might as well run a compression check. The motor was cold and hadn't been run since last year but I figured I would try it anyway. Using the standard cylinder numbering looking at the front of the motor, #1 is on the right, #2 is on the left, #3 is on the right, #4 is on the left, etc. With all the plugs out these were the readings.

#1 = 130, #2 = 87, #3 = 110, #4 = 112, #5 = 65, #6 = 112, #7 = 65 and #8 = 120

Oh, that seemed terrible, way to low and to much variability. This is a 1993, 454/7.4L Gen V 320 hp motor that should have something like 120 to 140 PSI from the factory. So I figured I would put a little oil in each cylinder and run the compression check again. This time it came up with this

#1 = 180, #2 = 120, #3 = 128, #4 = 140, #5 = 120, #6 = 135, #7 = 127 and #8 = 140

Really wild numbers, so what is going on I wonder. So I do some more research, talk to my son-in-law who is a pro diesel mechanic and gas guy and decided I have to warm up the engine some, then open the throttle all the way and run another compression check with all the spark plugs out.

So I got the fire extinguisher out and my ear protection and hit the key. I have to say the firing up that engine with no exhaust manifolds and fresh oil in the cylinders was pretty exciting, especially with the gas tanks on either side of the engine, smoke and flame and lots of noise. It fired right up like it usually does and, once the smoke cleared, settled down and run out smooth. There was still a lot more flame coming out of the exhaust than I expected, especially #3 and #5 and #4 and #6, the middle cylinders on each side.

Anyway, I let it run for about 6 or 7 minutes, shut it down, pulled the spark plugs and ran another compression check and got these numbers.

#1 = 125, #2 = 130, #3 = 118, #4 = 122, #5 = 95, #6 = 115, #7 = 110 and #8 = 120

I actually ran at least two checks on each cylinder and cranked it long enough that the needle quite moving completely so I think these are pretty accurate numbers, but they are still kinda low and more variable than I would like to see.

... I know, this is getting long but if I don't include all the info I'll just have to put it all in later.

Over the last couple of years I've noticed a slight drop in RPM on the engine at WOT. When I first got the boat it would run to 4200 RPM with no trouble, but lately its been only hitting 4100. 100 RPM don't seem like much but speed wise that is 3 or 4 mph on the top end. On top of that the impellers have been getting looser with 826 hours and no rebuild so I would have expected the engine RPM to actually have gone up a little, not down.

So now I don't know what to do. I hate to have to think about re-powering this spring. I was planning on spending a couple thousand on the boat not $10,000.... or more.

Just thinking, a few years back the engine started backfiring pretty bad through the carb under heavy load. At the time I found what seemed to be some bad spark plug wires, so I replaced the wires, put in new spark plugs, a rotor cap and rotor. The problem kinda went away and it certainly ran better, but I could still hear a slight popping through the carb when I took off at WOT. I finally called a mobile marine mechanic here in the valley and as soon he heard it he said that I had some bent push rods and intake valves that weren't closing all the way. He also said that this was something he had run into a lot on this type of 454 and was caused by backfiring. Hey, I was willing to try anything and sure enough, he pulled that valve covers and popped some of the push rods out and they were bent, they wouldn't roll on a flat surface. I think we replaced 4 total and I've probable put 400 hours on the boat since then.

Maybe I'll check the push rods again. Any other suggestions? Did I include enough info? Questions? I could sure use some help.

Those 300 hp FMJ diesels are sure nice but can a guy ever save enough fuel to pay back a $25,000 engine upgrade or is there anyway to even justify c-bolts LS2?

[Akgramps]

A compression test is a good first step, but mostly it just tells you the ability of the piston to make pressure and is best as a comparison between cylinders. You might consider doing a cylinder leak down test. It will help diagnose what is going on, lotsa of info on the net, but this seemed like a pretty good article......

http://www.dsmtuners.com/forums/arti...n-testing.html

[.338WM]

First, I would not be too concerned about the compression numbers after having the engine sit cold for so many months.

Secondly, the cylinder order on a GM V8 is right bank, as in starboard side, is #2,4,6,8 the left bank is #1,3,5,7 front to rear- firing order 1-8-4-3-6-5-7-2. You can check comp in any order you like, I normally did it front to back one bank at a time after all the plugs were out.

Next the reason for the "more flame" out of the center cylinders is that those cylinders get the lions share of fuel due to the design of the intake manifold, short runners vs. long runners.

Next, bent push rods are common on GM engines, V6 or V8. On a 454 there is issue with the rocker arm studs pulling loose form the cylinder heads, be sure to check the height on those.

When was the last time the carb had a going through? I am sure it could use a overhaul.

And if you are going to pull the push rods, there is no good reason not to look at the bottom of each lifter and the cam lobes.

A leak down test, as mentioned earlier is more informative but, personally, I would want to have an hour or two of that engine running prior to doing another comp or a leak down test before making a firm decision on a teardown/repower, although, I can about guarantee it would benefit from a valve job. The bottom ends on a 454 are about bullet proof when properly cared for.

Having said all of that I am guessing that reassembling everything (less the main shaft) in order to run it is unappealing. So taking that into consideration you have basically two choices:

1) pull it down to a short block and inspect the cylinder bores, if good, have a valve job and carb overhaul done and reassemble. Having the jet apart at this juncture would really tempt me to pull the whole thing, then pull the heads...the oil pan... the bearing caps... but being a mechanic, that is easy for me to say.

2) go right to putting a new long block in, or an alternative replacement LS6 or whatever. http://www.summitracing.com/parts/hp...FVBgfgodjmIA7Q

I have no idea what your skill set or comfort level is but, $10k sounds like you are of the mind to hire it out? Your post indicates to the contrary, though, it seems you have a decent amount of aptitude?

[bmunsell]

Thanks everyone for the replies and info, good reading in the links provided about compression and leak down tests. As recommended though I don’t think I will do anymore testing until I can run the engine more with the exhaust system connected. I’m still surprised at the amount of flame, I wouldn’t have thought that, even in the middle cylinders, there would be that much fuel left to burn when the exhaust valves opened.

As far as my skill set and comfort level goes, I haven’t had the heads off an engine in over 35 years and that was a 60s model 292 ford V8. I do have an experienced son-in-law so that is a big confidence builder but the other issue is time and equipment, I don’t have an overhead lift and I’m outside. On the other hand, access to the motor is really good and I could probably pull the heads without pulling the motor but that still wouldn’t give me access to the bottom end. I used to even rebuild carbs, mostly 2 barrel rochesters and 4 barrel quadrajets, but its been a long time. Of course, now we have Utube, 35 years ago we didn’t have computers, let alone the internet. Too funny.


Thinking about my options, the nice thing about the motor forward system is that it’s easy to disconnect the engine from the jet and the engine still has all its motor mounts intact so with a water hose jury rigged to the heat exchanger it can still be run, just no load of course.

So at this point I could easily check the push rods and rocker arm studs and then put the exhaust system back together and have the motor ready to go. In fact, once I get the jet parts back and we get some liquid water, I could throw in the drive shaft and go to the lake and really warm the engine up to see how it will run and for some good tests. But if I also pull the intake manifold to check the lifters and cam lobes then it does get harder to think about putting it all back together just to go run it for more testing.

To go further, pulling the motor probably wouldn’t be that hard and switching in a new, identical motor would be doable but actually getting into the bottom end, the bearing caps, etc and rebuilding my current motor would certainly be a challenge. I don’t know about going that far, fear of the unknown I guess. Well, and how reliable does an engine end up being.

As far as changing motors, say to the LS6, seems like a whole different can of worms, leading to impellor changes, etc. Even going to a newer 454 with EFI and more horsepower could get more involved. At some point I guess a guy has to figure how much he even likes the boat. Hmmm.

[.338WM]

As far as changing motors, say to the LS6, seems like a whole different can of worms, leading to impellor changes, etc. Even going to a newer 454 with EFI and more horsepower could get more involved. At some point I guess a guy has to figure how much he even likes the boat. Hmmm.

Which is why I linked the long block from Summit Racing, all you would have to do is swap the sheet metal and manifolds, etc., and you still have a carbureted engine plus, near 100 more horsepower, at a very reasonable price.

Or, get the jet pump back to spec. and run the engine how it is now for another season gives you more time to ponder...

[bmunsell]

I thought I would add that the engine doesn’t smoke or go through a lot of oil, maybe a quart every 40 hours or so, depending on whether we are doing a lot of idling dip netting or trolling on the main motor or just running. Figuring that normal cruise is at 3600 RPM I would expect a motor to use a little oil and it has done that with no change since I’ve owned the boat.


Also, I’ve looked at the Summit Racing site and they list a long block 454 with 415 hp and 497 ft.-lbs. of torque for just over $3,600. I don’t know what the freight would be to here but it sounds like a great price.

[.338WM]

I thought I would add that the engine doesn’t smoke or go through a lot of oil, maybe a quart every 40 hours or so, depending on whether we are doing a lot of idling dip netting or trolling on the main motor or just running. Figuring that normal cruise is at 3600 RPM I would expect a motor to use a little oil and it has done that with no change since I’ve owned the boat.


Also, I’ve looked at the Summit Racing site and they list a long block 454 with 415 hp and 497 ft.-lbs. of torque for just over $3,600. I don’t know what the freight would be to here but it sounds like a great price.

That is the one I linked in a previous post, most likely. Certainly worth considering. For what it is worth, I have installed several ATK engines (automotive applications)over the years and have never had an issue with them, plus, since Summit is selling it you would have them backing it up as well.

[bmunsell]

1993 454 Repower

Since it's getting to be that time of the year and we got no snow to speak of, it's time to think about boats. I'm considering repowering my 1993 Wooldridge Deeper V Classic, 320 hp 454 and am wondering who is best to go with these days. I've been looking at the USENGINES.COM site and see that they advertise here on the forum and wonder if anybody has bought from them. Just a short search on the internet pops up a few disgruntled customers, but so far I haven't come across anyone from Alaska with a complaint.

My current engine only has about a 1,000 hours on it but it's down on power some, though it still runs good and doesn't burn any oil. I've done some different compression checks on it and always get really erratic numbers (low 90's to high 140's) but I haven't taken it to anyone else yet. At most current shop rates it seems I could easily spend $500 to $1,000 just finding out it has some burnt valves or worn cam or who knows and I think I would just as soon put the money in a new engine with a little more horse power.

Usengines advertises a 410 to 450 hp 454 that supposedly will burn "around" 25% less fuel and that sounds pretty attactive but also sounds kinda far fetched. Looking for advice and info.

[Sobie2]

I believe the 6.0 liter marine engine (Volvo, Mercruiser, etc) is the replacement for the 454 (330 HP) and they make around 380 HP. The general accepted rule of compression is that all cylinders are supposed to be within 10% of each other. The 6.0 is better on fuel by a long shot as well.

Don't forget to get your pump back into shape. Its counter intuitive, but a pump that needs to be shimmed will take more HP to turn, and you have to rev it higher to get the flow you need.

Sobie2

[bmunsell]

I had the pump rebuilt last year which, of course, made the drop in power on the engine even more apparent. When I first bought this boat with about 140 hours on it, that engine would hit a good strong 4200 RPM. Before the pump rebuild it could only get 3900 and now it's 3800 or a shade lower. Now 3 or 400 rpm may not seem like much but going down river that's the difference between over 45 mph down to about 40 mph under similar conditions of load, etc.

The problem with going to any other engine block and especially to a fuel injected engine is having to redo engine mounts, exhaust and wiring. I think I would rather just stay as close as possible to the original.

[MacGyver]

Before I start looking for a new engine I would lock down the compression numbers. Was the engine warm, did you have the carburetor wide open and the air cleaner off, was the battery fully charged and the engine turning over fast? They all effect compression.

A leak down test if done properly can tell you a lot about the heads.
What do the spark plugs look like?
Do you have a vacuum leak?
When was the last time you did a major tune up and did that include the carburetor, and spark plug wires?

[bmunsell]

I ran a compression check on the engine about 4 different times last spring trying to get all the bases covered, warm engine, all the plugs out, read some more, air cleaner off, carb open, good battery. I can pull the drive line on this boat so I don't have to worry about spinning the jet dry. Read some more. Didn't do a leak down test because by that time it was time to go fishing. Did get new plugs and plug wires, rotor, rotor cap. Didn't do the carb. Always got roughly the same numbers for each cylinder.

I guess that's the problem with doing all your own work, making the time to get it all done. So, I can spend another month messing with it, but if the heads do need work, I'm still back to a new engine. If I was going to sell the boat I could just do a valve job (probably not, I hate farming my boat problems off on some unsuspecting person) and call it good, I've done that on a truck or 2 before, but over the long run, reworked heads just seem to put the stress somewhere else and then I'm back to a new engine.

Still wondering where the best place to buy an engine is?

[MacGyver]

Sorry I thought you may have miss something when doing the compression test. I did not mean to offend you.

[bmunsell]

Oh, no offense at all. I really appreciate your comments. It never hurts to go back over the basics. I guess my frustration with the engine from last spring is still coming through. With only a 1000 hours it doesn't seem like it should need to be replaced but pinning down the problems and what to do about them seem hard to do and time consuming.

[Sobie2]

Here in Juneau, when we had a boat with twin gas engines, the towns best mechanic (and we tried them all over the years) always bought his engines for re-powers from Michiganmotorz dot com. And he took care of a few charter boats with gas engines and they all seemed happy with them. I'd start there.

Sobie2