90hp block is damaged and I need some advice

[fire7882]

The previous owner must have gotten really mad at this motor and decided that taking a hammer to it would cure all his frustrations. After cleaning various parts, I got out a razor and started removing the old gaskets from the power head. I soon noticed the starboard side cylinders have dints and gouges everywhere between the head and block mating surfaces. Worst of all, the outer surface of the cylinders are missing a small chunk of metal.

I'm not sure where to go from here. The PO had the voids filled with JB weld and the compression was fine so I might do the same for the time being. I'll be keeping an eye out for a good yet affordable power head but still plan to piece this one back together. I have a 1964-65 evinrude 90 hp OB that I'm hoping has the same block as this one. Even though I doubt it does, I'll use the possessed power head until I can get the 64-65 block rebuilt. Below is a picture comparing a 1968 block to a 1992 block. The evinrude parts catalog didn't go back to 1965.

My restoration thread
http://forums.iboats.com/showthread.php?t=265171


Any suggestions or advise is greatly appreciated.

 

[Daviet]

Re: 90hp block is damaged and I need some advice

The defects around the outside, by the head bolts, would only cause a water leak. The defects around the cylinder liner MIGHT not be a severe problem as the steel liner sealing on the head gasket captures compression. That being said, you have lost some gasket compression area at those two points. I have seen repairs using JB weld to build up the area, file it down smooth so the gasket seals properly. I guess my personal thought is, what have you got to loose by trying to repair, can't do any more damage to the block.

 

[R.Johnson]

Re: 90hp block is damaged and I need some advice

Can you measure how deep those dent's are? If nothing else you could use a straight edge, and feeler guages. If they prove not to deep, a shop could smooth it off. By the way, don't use a razor blade to clean gasket surface's. The process of smoothing is called decking. I had it done when ever having an engine rebored.

 

[fire7882]

Re: 90hp block is damaged and I need some advice

you have lost some gasket compression area at those two points

This is my fear but as you stated, I have little to lose. Would filling the voids by welding be an option or could that distort the cylinders or cause bigger troubles? The bad places around the outside aren't a huge concern, it's just aggravating that someone didn't take the time to do things right. Thanks for the help.

 

[R.Johnson]

Re: 90hp block is damaged and I need some advice

It would be interesting to know just how that happened. You would'nt have a reason to pry, or strike there.

 

[Daviet]

Re: 90hp block is damaged and I need some advice

I don't think I would try welding, steel liner against aluminum block. I would just build up the area with JB weld and file down flush. Make sure and clean area really good before using the JB weld. Just my thoughts.

 

[fire7882]

Re: 90hp block is damaged and I need some advice

the dents are to deep to be removed by decking. The broken pieces on the cylinders are about 1/8 inch deep. I didn't plan to have anything machined or remove internals so decking wasn't an option. I only planned to replace most of the gaskets and clean/decarb the powerhead but ran into many other problems.

 

[fire7882]

Re: 90hp block is damaged and I need some advice

It would be interesting to know just how that happened. You would'nt have a reason to pry, or strike there.

I agree. It dosn't make sense.

I don't think I would try welding, steel liner against aluminum block. I would just build up the area with JB weld and file down flush. Make sure and clean area really good before using the JB weld. Just my thoughts.

Would you just fill the voided areas or fill the space inbetween the cylinders as well to strengthen it a little.

Fill between the red lines and maybe 1/2 inch below deck surface?

 

[Daviet]

Re: 90hp block is damaged and I need some advice

I would just fill the voided areas. Clean the area well and let it cure properly, file it down smooth.

 

[tx1961whaler]

Re: 90hp block is damaged and I need some advice

You can use JB Weld, but I'd look at using Devcon aluminum:
http://www.devcon.com/products/products.cfm?brandid=1&familyid=107

 

[R.Johnson]

Re: 90hp block is damaged and I need some advice

No matter what brand you use! You are talking glue here. How hot do you suppose that cylinder sleeve get's before cooling water carry's it away.

 

[HybridMX6]

Re: 90hp block is damaged and I need some advice

I've heard of people having chips like that welded with a TIG welder. I have no idea how to weld, but thought I'd mention it to you as an alternative to JB Weld.

 

[jonesg]

Re: 90hp block is damaged and I need some advice

Try this stuff, looks ideal.
watch the video

http://www.aluminumrepair.com/video_new.asp

 

[fire7882]

Re: 90hp block is damaged and I need some advice

Try this stuff, looks ideal.
watch the video

http://www.aluminumrepair.com/video_new.asp

Thanks for all the replies and help. I'm going to give the stuff above a try. This stuff looks great and thanks for the link. I just ordered 10 9" rods on ebay for less than $15 shipped and will post here with the results.

 

[kencat]

Re: 90hp block is damaged and I need some advice

Would you just fill the voided areas or fill the space inbetween the cylinders as well to strengthen it a little.

Fill between the red lines and maybe 1/2 inch below deck surface?

Filling as suggested looks like it would block water flow - not a good thing I think.

Also, the "damage" at the liners looks like erosion of some sort, not mechanical damage. Perhaps galvanic or from pressure/flow of gases or water. Note that one of the steel liners is eaten away a bit on the aluminum side. Even the damage on the outer rim may not be from a person. Would have to see in person, but it all looks too smooth.

Could be wrong, but worth considering.

 

[fire7882]

Re: 90hp block is damaged and I need some advice

Filling as suggested looks like it would block water flow - not a good thing I think.

Very possible but if I did use this method, I would only go about .5 inches below the deck surface. You can fill the water jackets with sand and then add the jb weld, exc.. to the damaged areas. I've seen this method used before on Devcon epoxy based block guards in performance engines like the one below. I don't think it's the best route, but worth exploring.

Also, the "damage" at the liners looks like erosion of some sort, not mechanical damage. Perhaps galvanic or from pressure/flow of gases or water. Note that one of the steel liners is eaten away a bit on the aluminum side. Even the damage on the outer rim may not be from a person. Would have to see in person, but it all looks too smooth.

It is smoothed out because I used a wire brush to clean out all the old JB weld. I'm going to attempt to use the aluminum brazing rods jonesg posted above for the repair.

 

[kencat]

Re: 90hp block is damaged and I need some advice

Very possible but if I did use this method, I would only go about .5 inches below the deck surface. You can fill the water jackets with sand and then add the jb weld, exc.. to the damaged areas. I've seen this method used before on Devcon epoxy based block guards in performance engines like the one below. I don't think it's the best route, but worth exploring.

The thermal bridge created could still cause unknown/detrimental effects, but the sand technique might make applying the filler easier over the larger area and make filing/stoning the face easier, then remove the material between bores to put back to original design. Neat idea.

It is smoothed out because I used a wire brush to clean out all the old JB weld. I'm going to attempt to use the aluminum brazing rods jonesg posted above for the repair.

I did say I could be wrong :redface:

Look forward to see how you make out with the repairs.

 

[reelfishin]

Re: 90hp block is damaged and I need some advice

For what its worth, I've used Devcon aluminum putty on cylinder heads before, even in combustion chambers, it's good stuff that stays put. Heat doesn't seem to affect it. It's nearly impossible to get off too. Go to the local speed shop and look for some Moroso 35560 A&B Epoxy, we use the stuff when porting cylinder heads to fill or back thin spots. If it holds up in a car running 13+:1 compression and a blower, it should be fine in a low compression outboard.
Just be sure to clean the area to be filled really well, I'd consider glass beading that area and pressure washing the block well when done.

 

[fishrdan]

Re: 90hp block is damaged and I need some advice

This stuff looks great and thanks for the link. I just ordered 10 9" rods on ebay for less than $15 shipped and will post here with the results.

I've used some of that stuff (well not HTS2000, but close) and it's harder to work with than it seems, goes from solid to liquid in a very narrow temp range and is very runny. Trying to fill that area would be very difficult unless you can figure out some way to contain it, piece of steel to form a pool. Those rods are very hard compared to the aluminum block, so you will need to be very careful not to ding up the existing machined surface while grinding the repair down.

Not saying it can't be done, but it's not as easy as adding metal by welding. Temperature control will be your hardest obstacle, when it's hot enough to melt it's also liquid enough to run off the area you are trying to build up.

 

[fire7882]

Re: 90hp block is damaged and I need some advice

The thermal bridge created could still cause unknown/detrimental effects

I agree. The expanding and contraction metals could also cause it to crack and become lodged in the water jackets, causing other problems.

For what its worth, I've used Devcon aluminum putty on cylinder heads before, even in combustion chambers, it's good stuff that stays put. Heat doesn't seem to affect it. It's nearly impossible to get off too. Go to the local speed shop and look for some Moroso 35560 A&B Epoxy, we use the stuff when porting cylinder heads to fill or back thin spots. If it holds up in a car running 13+:1 compression and a blower, it should be fine in a low compression outboard.
Just be sure to clean the area to be filled really well, I'd consider glass beading that area and pressure washing the block well when done.

This is definitely a good option. I'm going to try my luck with the brazing rods first. Hopefully I'll get them this week.

I've used some of that stuff (well not HTS2000, but close) and it's harder to work with than it seems, goes from solid to liquid in a very narrow temp range and is very runny. Trying to fill that area would be very difficult unless you can figure out some way to contain it, piece of steel to form a pool. Those rods are very hard compared to the aluminum block, so you will need to be very careful not to ding up the existing machined surface while grinding the repair down.

Not saying it can't be done, but it's not as easy as adding metal by welding. Temperature control will be your hardest obstacle, when it's hot enough to melt it's also liquid enough to run off the area you are trying to build up.

I had assumed it might be hard to control but figured that for $15, it was worth a shot. The block is pulled from the outboard so i can rotate it so that the surfaces I'm working on are flat and I hope a piece of flashing will contain the metal on the cylinder sleeves. I also have a friend with a machine shop that could deck the surfaces if i decide to tear the motor down. If it doesn't work, I will try one of the other great solutions mentioned above.