'73 chrysler 105 surges at WOT then loses power

[spool]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

Good to know Frank, Do you mean the locating pin for the crankcase halves?

As you can probably tell from the photos i've already removed the lower crowl. I may remove the lower leg to make it easier to crack the midleg off.
I'll see if i can find a impact screw driver, failing that ill just drill them and use a easy out. (reverse thread tap of sorts)

 

[Frank Acampora]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

Yes, there are two locating pins about 5/16 inch diameter. One is interfered by the block: You can drive it far enough to clear the front half but not all the way out. To reinstall it you need to wedge it up with a big screwdriver.

By the way: You can not split the crankcase until it is off the midleg. At the bottom there is a match plate and four studs go throug it. Two of those studs are in the front half of the crankcase. Once you get the block loose, there is an exhaust downtube about 10 inches log with a flange near the bottom. This flange interferes with the water tube mount and you will need to twist the engine to clear it. Either use two men or a hoist to lift the block. It weighs around 100 pounds (45 Kilos) and while that is not too heavy for the average male, it is awkward. Two make it a lot easier.

 

[spool]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

Yes, there are two locating pins about 5/16 inch diameter. One is interfered by the block: You can drive it far enough to clear the front half but not all the way out. To reinstall it you need to wedge it up with a big screwdriver.

By the way: You can not split the crankcase until it is off the midleg. At the bottom there is a match plate and four studs go throug it. Two of those studs are in the front half of the crankcase. Once you get the block loose, there is an exhaust downtube about 10 inches log with a flange near the bottom. This flange interferes with the water tube mount and you will need to twist the engine to clear it. Either use two men or a hoist to lift the block. It weighs around 100 pounds (45 Kilos) and while that is not too heavy for the average male, it is awkward. Two make it a lot easier.

I've got a engine crane/stand that i can use, I'll give it a good crack tonight

 

[spool]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

Removed the lower leg and mid leg last night, punched out the crank case pins too, getting an impact screw driver tonight and flywheel puller then I'm ready to split the crank case

The exhaust snout seems to be a bit cracked, yet another thing to replace


The water passages up to the pump through the sandwich plate have seen better days, I think water was leaking out before it even got to the engine

Does this engine have a thermostat? If so where?

 

[spool]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

Split the crankcase today, the bearings look good. No pitting on the rollers and they all seem in good condition.

I measured the conrod bolts with a micrometer and it came to 7.05mm

In the manual the socket is a T2953, it looks like a standard multihex socket, what is the exact size of this socket?

 

[labawg]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

In photo four is that a crack in your crank?

 

[Frank Acampora]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

Remember: This engine is old American technology before the metric system. ALL threaded fasteners are either national coarse or national fine and all are in inches. In your case the con rod cap bolts take a 12 point 1/4 inch socket while the threads are 1/4 X 28 national fine.

 

[spool]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

THe crank isn't cracked. Its just a casting line. Its down to a bare block now

Remember: This engine is old American technology before the metric system. ALL threaded fasteners are either national coarse or national fine and all are in inches. In your case the con rod cap bolts take a 12 point 1/4 inch socket while the threads are 1/4 X 28 national fine.

thanks Frank, i worked out it was 1/4" 12 point, i got the proper socket and removed the rods.

The 2nd piston's rings are both seized, the lower ring is grinded /melted into the piston. All 4 need replacing and i'd say atleast 3 cylinders need to be oversized, I'll see what the machine shop thinks.

CARNAGE PICS!

Piston 1 & 2
View attachment 119370

Piston 3 & 4
View attachment 119371

Engine block
View attachment 119372

2nd Piston
View attachment 119373
View attachment 119374


Off to the machine shop in the next few days to see what can be done about it and to see if the block is reusable after an oversize...

My conclusion seeing pistson 3&4 which had no fuel/oil supply issues is that the engine was already in need of a rebuild.

 

[spool]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

Any comments on the damage????

I removed the exhaust chamber plate, 38 years of seawater and heat destroyed the bolts, out of the 28 bolts, 16 snapped their heads off.
I used a penetrating oil which loosened up alot of them and i was able to remove all but 6 with vice grips... Then i snapped a easy-out in a bolt (DOOHH!!! They should call them easy snaps)

Ive got heli coils the right size, I guess ill drill them out and retap the thread.

 

[Frank Acampora]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

Those bolts only have about 1/8 inch wall thickness in the block casting. Heli-coils will remove half that. What I do is retap further down. The bolt bosses go all the way to the cylinders so if you are careful you can drill deeper, tap 1/4 X 20 -- or metric if you want---and use longer bolts. However, as I said, you must be careful. Aluminum galls on deep drilling and the bit may snap. Drill a bit, withdraw the bit and clean it, then drill a bit deeper---etc until you get to the depth you want. Drill press really is helpful here.

 

[spool]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

Those bolts only have about 1/8 inch wall thickness in the block casting. Heli-coils will remove half that. What I do is retap further down. The bolt bosses go all the way to the cylinders so if you are careful you can drill deeper, tap 1/4 X 20 -- or metric if you want---and use longer bolts. However, as I said, you must be careful. Aluminum galls on deep drilling and the bit may snap. Drill a bit, withdraw the bit and clean it, then drill a bit deeper---etc until you get to the depth you want. Drill press really is helpful here.

I'll give it a shot frank,

I took the block in to be bored out today, I'm getting all 4 bored out as atleast 3 need it, I'm doing 4 to be safe, I'm going for a 30thou bore, Ordered the pistons today.

Is there any trick to removing the piston rods? If i press them out will i damage anything?
Do i need to order new bearings for the wiseco pins/pistons?

 

[Frank Acampora]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

If you do not intend to re-use the pistons or needle bearings from the small end of the rod, then just press them out. The piston will be deformed a bit and the needles will dent the keepers but the rods will be OK.

NOW: If you ordered Wiseco pistons, you must use the bearing kit AND the wrist pin is free-running, held by circlips.

If you bought stock pistons, to keep from squeezing the needles between the keepers and jamming them, you must use a special .310 spacer. Chrysler made a special tool that was double ended with something like .280 on the removal end and .310 on the installation end. It should be relatively easy to make. You would also want to make a curved pillow block to match the piston curve so installation pressure does not deform the piston.

Be aware that wrist pins on stock pistons can vary from a couple of thousands interference to a couple of thousands loos. Only the keepers (or stepped collars) Must have the tight interference fit to retain the wrist pin. They too vary and some are really tight, taxing a 6 ton press to remove.

If I can find it, I will take a photo of the tool later in the day. (8:30 AM here)

 

[Frank Acampora]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power



As promised, here are a couple of photos of the spacing tool used to remove and insert wrist pins. The narrow part of the "U" shape fits over the narrow part of the keeper and the keeper bears against the piston. The wide relieved part clears the needles. The .310 is the total thichness of the tool and allows space between the needles and keepers when the tool is inserted on the bottom side between the con rod and keeper. Since the gap will narrow a bit when the tool is removed, the .295 is sized for removal of the wrist pin. .310 will not fit into an assembled wrist pin/con-rod
When you press in a wrist pin, the tool will get jammed between the con-rod and keeper and must be worked out.

 

[spool]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

If you do not intend to re-use the pistons or needle bearings from the small end of the rod, then just press them out. The piston will be deformed a bit and the needles will dent the keepers but the rods will be OK.

NOW: If you ordered Wiseco pistons, you must use the bearing kit AND the wrist pin is free-running, held by circlips.

If you bought stock pistons, to keep from squeezing the needles between the keepers and jamming them, you must use a special .310 spacer. Chrysler made a special tool that was double ended with something like .280 on the removal end and .310 on the installation end. It should be relatively easy to make. You would also want to make a curved pillow block to match the piston curve so installation pressure does not deform the piston.

Be aware that wrist pins on stock pistons can vary from a couple of thousands interference to a couple of thousands loos. Only the keepers (or stepped collars) Must have the tight interference fit to retain the wrist pin. They too vary and some are really tight, taxing a 6 ton press to remove.

If I can find it, I will take a photo of the tool later in the day. (8:30 AM here)

Thanks Frank, I ordered 4x Wiseco 30thou oversized pistons (as per the machinists recomendations)
So if i just press them out (all my pistons are shagged) the rod will be ok? thats the only thing i need from it. The loose fit with a circlip should be easy to install
I've got a mate with a press at his workshop that will press them out for me. I'll need to find some new wiseco bearings for the piston end of the rod.

Ordered a gasket kit today, when the machine shop gets the pistons they will finish the bore & hone. It should all happen in the next two weeks... can't wait to hit the water again

*sigh* I don't understand why US companies sell motors in other countrys then refuse to ship spare parts here Wiseco included. There are a few shops that do ship to Aus but not exactly legally. It's making finding a shop with the bearings in stock very difficult.

 

[wolfie-uk]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

*sigh* I don't understand why US companies sell motors in other countrys then refuse to ship spare parts here Wiseco included. There are a few shops that do ship to Aus but not exactly legally. It's making finding a shop with the bearings in stock very difficult.

I'm with you on that one mate, the aggro i get trying to get parts here in England is stupid, they tell me to go through the Mercury dealerships, and when i compare prices what costs ( after conversion ) ?20 in USA, the rob dogs over here want ?65 for the same item, thats why i buy all the old Chryslers i can for spares, the 85 i am rebuilding at the moment needs a piston, guess how much the Merc dealer wants.....?110 for one piston and rings, so i am ripping out a 70 skier and using the best one out of that.

 

[Frank Acampora]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

Rod is fully hardened and there is almost nothing you can do to damage it. So, yeah, just press out the wristpins. And yes, you do need the Wiseco bearing kit. The keepers are spacers and loose on the wrist pins and they are smaller than stock

Don't let the machine shop get confused: When you order .030 over pistons, that is not their actual size. Pistons are machined to fit correctly in a .030 overbore. So: The machine shop does not need to wait for the pistons. Your engine has a 3.3125 bore. (3 5/16) Plus .030 make 3.3425. So that is what the finished cylinder after final honing should be (plus or minus a couple of .0001 for tolerance)

The pistons are also "cam-ground." They actually have an oval shape with a major and minor diameter to account for uneven heat expansion inside the cylinder. At operating temperature they become round.

 

[spool]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

The machine shop said they'd bore it then wait for the piston to do the final hone, It's how i've always built my engines and its worked for me so far without any problems.

Wolfie I was lucky enough to find a dealer in Aus selling the piston kits cheap from within australia for $70 AUD each express post (3129P3) I'm not having so much luck with the small end bearing kit
Perhaps you could buy from the Australia retailer and have them shipped to the UK as they are less than 1/2 the price you've been quoted.

 

[spool]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

Found the bearing kits locally

Just waiting on the pistons and bearings/gaskets & all the other stuff i ordered over the last few weeks

 

[Nordin]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

About spareparts outside the US, I am living in Sweden Europe and I always buy spareparts from Franz Marine. He knows what you need and he is really serviceminded. The prices are a little bit higher then iboat, outboardparts.com, maxrules .... but way cheaper then the Mercury and Quicksilverdealers over here and Franz has allmost everything you can get in Chrysler/Force parts.

 

[spool]

Re: '73 chrysler 105 surges at WOT then looses power

Re: '73 chrysler 105 surges at WOT then looses power

Pistons and bearings arrived. I got the Wrist pins pressed out. Dropping the pistons off to get the bore/hone done.

Just have to work out what gap i need to run on the piston rings. It's getting there. =/
With anyluck ill beable to pick the engine block up early next week. and start assembly.

I also ordered a water pump kit (housing, impeller and gaskets)

Does anyone know what OHM the water temperature sensor is in the head? I'll be installing a gauge so i don't overheat it again.