1976 Chrysler 105 - winter project

[Arawak]

Full album on Google+ <---- I'll keep updating this for those who want to see all the photos

Ok, so I really did intend to part this out when I bought it.

But, after walking past it every day in my garage the itch started, and now, well..... I do need a winter project...

So, with some difficulty I got the lower unit off. The drive shaft was stuck, but with just two bolts loosely holding it on, I rocked the flywheel back and forth sharply a few times and got it off. Took off the water pump housing, removed the impeller and the gasket. Vacuumed out a ton of debris (acorn shells!). Ordered new impeller and gasket, should have sometime next week.

At this point I'd like to check the compression. Any reason I can't turn it over with the LU off?

 

[Frank Acampora]

The only reason not to crank it with the lower unit on is no water to the impeller.

Without the lower unit you can even start and even run it run it as long as you don't run it long enough to overheat it.

BTW: The approved method for unsticking a drive shaft is almost exactly as you did.

Understand that this particular engine was rated at the block and when prop rating came into play, it was simply downrated to 90 HP. Now, the lower unit is a relatively poor design so performance will be even less than any comparitave 90, including later Chryslers. Add to that the 18 spline, thrust pin props are becoming difficult to find. Not trying to discourage you, buy you should know before hand what you are getting into.

The block and cowling CAN be mounted on a later Chrysler or Force one piece leg and you will see a bit better performance in addition to having a better prop selection.

 

[Arawak]

Thanks, Frank. Tomorrow night I'll hook up a battery and see how the compression is.

I have followed your posts on the topic, so I'm aware of the shortcomings of the LU. Not too concerned... it's primarily a learning project, and I do have two 18 spline props for it.

 

[oldboat1]

I sometimes flush them by attaching a water source to the tube, and running some water through (need a tight fitting hose -- fuel hose or something, rigged to a pump or source -- garden hose, if pressure is kept reasonably low). It sounds like a little flushing could be called for, if there were some critters making a home.

Could run the engine a bit that way too, I think. Keep it at idle. Won't have back pressure without a l.u. in water, but powerhead should cool (would want to check it). A driveway project -- maybe could find out a little more about what you have there.

 

[Arawak]

I sometimes flush them by attaching a water source to the tube, and running some water through (need a tight fitting hose -- fuel hose or something, rigged to a pump or source -- garden hose, if pressure is kept reasonably low). It sounds like a little flushing could be called for, if there were some critters making a home

That's a good thought. But... I wonder if I wouldn't be better off flushing it in reverse, so I don't wedge something up in the block. Maybe start with compressed air at the thermostat.

 

[oldboat1]

Both ways.

 

[Arawak]

Sprayed by WD40 into each cylinder, let it sit for 45 mins, then ran compression test (cold).

#1 - 110
#2 - 115
#3 - 150
#4 - 140

Guess I'll pull the head off and have a look.

 

[Arawak]

Well, I'm quite a newb at this, but the cylinders look okay to me for a motor that has been sitting for a couple years. No obvious scoring.

However, there are some marks on #1 piston and on the inside of the head. Not sure what to make of this.

 

[oldboat1]

poss. pre ignition damage? wrong plugs (reach too long)?

 

[Frank Acampora]

I can't open your photos. Can you post them a different way?

 

[Arawak]

Ugh, vbulletin is the worst!

Maybe now?

 

[alldodge]

Just upload Pics from your computer

 

[Frank Acampora]

That is not detonation or pre-ignition. The engine at one time ate a screw or bolt. Notice on the head directly across from the plug it has thread marks. Also notice that those thread marks correspond to the long slash mark on the exhaust side of the piston and you can also see faint thread marks on the piston

Now, that looks about the size of a 1/4 inch bolt and that simply could not pass through the reeds. Logic leads us to believe it was left in the engine at rebuild. Does the engine show any signs of a rebuild? Is there RTV silicone or similar between the flanges of mating crankcase halves? Are all the bolts missing paint or showing signs of being removed and retightened? Are carb bolts slightly rounded at the corners? etc. If you have a caliper, measure the bore. If it is significantly larger than 3 3125 ( .010, .020, or .030 larger) then the engine has been rebuilt with oversized pistons.

If you open the exhaust cavity check the bottom of that piston skirt (or in fact all of them) for obvious damage of a bolt getting jammed at bottom dead center. If they are stock or aftermarket cast pistons The bottom of the skirts will have some pieces broken off. Remove the bypass covers and check also.

Since this is a winter project and basically an exercise in learning, if money is available and if the engine has not been bored out to maximum (.030) You may want to consider complete disassembly and rebuild based on the low compression readings of # 1 and 2. Be aware that the lower compression MAY simply be due to stuck rings. Stuck rings may possibly be released by a good snake-oil treatment but I doubt it.

 

[Arawak]

Thanks AllDodge, that's what I tried first but vbulletin didn't like my JPEGs. In the end I posted them to my personal server. WIll move them to flickr or something at some point. My frustration was with vbulletin caching pages.

 

[Arawak]

Wow, Frank, you never cease to amaze. That would explain it. There's definitely been work done to this motor, but not sure what extent. The carbs have been off for sure, but I can't tell much more than that. It did have a car coil conversion, so they may have been off during the troubleshooting process before that.

But in any case, I'm definitely up for a rebuild. I'm not at all adverse to spending more money than the motor's worth for a fun winter project

Tomorrow I'll open her up and see what I find.

 

[oldboat1]

Thanks AllDodge, that's what I tried first but vbulletin didn't like my JPEGs. In the end I posted them to my personal server. WIll move them to flickr or something at some point. My frustration was with vbulletin caching pages.

(Frank is good!)

To upload pics, think it's easier to put them on your desktop, and click on the camera icon on the left when ready to post, then follow the prompts. Seems to work.

 

[Arawak]

Spent part of today getting ready to pull the power head.

 

[Arawak]

Right now I'm thinking to just hone the cylinders and re-use the pistons (assuming there's no damage to the skirts). Back in the old country they would just re-use the rings (and likely the head gasket too) but I was planning to get new rings and this head gasket is in too poor shape to re-use even if I wanted to risk water in the cylinders.

Surprised at how expensive rings are, but oh well.

Powerhead is all ready to pull, but I have to safely hook the chain hoist up to the i-beam in my garage. That means drilling a couple holes on the bottom edge and bolting chain to it. Maybe tonight.

I'm guessing that the screw that caused the damage to piston #1 came from the reeds. Can't think what else it could be. But I'll find out once I get it apart.

 

[Arawak]

Got a little distracted. Didn't like the wooden motor stand we hacked up out of old lumber so I put the welder to use and ended up with this:




But, I did manage to get back on the programme, and tonight after much tribulation, the powerhead is out:





So I guess next step is to remove the flywheel and the stator.

 

[alldodge]

Moving right along