Repairing a vented small engine block

[NASTYZEN]

This winter there were a few questions re fixing vented small engine blocks. This one didn't throw a rod but rather fell of the back of a truck, resulting in a cracked block. This is my technique of fixing them.

First I burn off the oil witch seeped into the porous Alu. Otherwise it's near impossible to weld up.

Next I wire brush the whole area clean. If you do this while it's still hot you also remove the top layer of oxide witch melts at a higher temperature than the base metal and also makes it hard to weld properly.

Then comes the die grinder to notch the crack to get better penetration and also removes some of the impurities.

I usually weld the inside first because there is always a little porosity from the impurities, then die grind the outside cracks right into the inside weld to make it as clean as possible.

Finally the outside gets welded up. Nowhere near the beauty of ZTfab's welds, but it does the job. It is a snow blower block after all.

 

[OccupantRJ]

That ought to do it. You just gonna flat file the mating surface for the cover?

 

[e-tek]

VERY Cool! Wish I could have done that to one of the Flathead blocks I had to trash! I know it can bedone - with the lock'n'stitch procedure - but not in my case!

Was going to ask the same question as Occupant!

 

[NASTYZEN]

That ought to do it. You just gonna flat file the mating surface for the cover?

Cheated and just used my hand grinder.
When things are to be really flat I have a large piece of sand paper that I lay down on a flat metal surface and then make circles on the paper with the block till it's uniform.

VERY Cool! Wish I could have done that to one of the Flathead blocks I had to trash! I know it can bedone - with the lock'n'stitch procedure - but not in my case!

Was going to ask the same question as Occupant!

I've often used brazing to fix cast iron in the past. The racing school cars crashed, often Knocking off mounting ears. The guys were always proud when they showed up with the bits that had fallen off,t'ill they saw me chuck em in the garbage...Always way more solid to just build up the ears with bronze and grind them back to shape and re drill the holes.

 

[ZTFab]

Looking good!!!

Nice job on the repair.....

...and remember, welds are like women. We all like to look at the pretty ones but they don't have to look good to be the best.

 

[Jzytaruk]

stick or tig? nice repair work

 

[NASTYZEN]

Looking good!!!

Nice job on the repair.....

...and remember, welds are like women. We all like to look at the pretty ones but they don't have to look good to be the best.

Ha ha! I like that I try harder at aesthetics where it counts, still nowhere like yours though.

stick or tig? nice repair work

Stick??? Nah...T.I.G.

 

[56nash]

Had that same repair done many times when my son raced go karts. Briggs blocks weld up well too. Funny those little flathead lawnmower engines can really make some power but can also make one hell of a big bang when that rod comes apart at almost 8K RPMs. We even JB Welded a block at the track and threw a new rod in the day of a race so he would not lose points by not starting in the main that he had qualified for. We figured if he at least made a lap we would be good. That damn motor was still running when he got out of kart racing.

 

[vpd66]

I welded reinforcements on a 6.5hp Honda block for a kart racer this winter. I too used a torch to melt off any grease/dirt and then used a 60 grit flap wheel where I was going to weld. I tig welded it and my welds looked simular to yours. Not picture perfect, but strong enough to get the job done. That cast aluminum on those Honda blocks just kind of welds funny. I don't know if it is all the oil that soaked into the pours or if it is the quality of the casting.

 

[diesel research]

Stick??? Nah...T.I.G.

While it sounds crude and horrid, you can stick weld aluminum, especially thick stuff or for building up. Used to do build up welding in aluminum armor plates (sounds like an oxymoron) that would have pock marks from shrapnel. It's really smokey and fast paced/violent, but very quick.

Do you "terminate" your crack repairs by drilling holes at the ends?

 

[theoldwizard1]

I saw an old B&S vertical that had a hole in the side patches with a small piece of sheet metal, some RTV and 4 self tapping screws. Kept the oil inside !

 

[cruzn57]

I didn't do the repairs, as its beyond my skill level,
but with the price of this block, I HAD to repair it!
he reconstructed both sides, and heated the block to decrease distortion.
checked align bore afterwards, perfect! cam spins freely too,
I guess you pay for experience.

 

[nate379]

GNX block?

 

[diesel research]

GNX block?

It's aluminum, so that's HIGHLY unlikely. They were cast iron like the rest.


If you are a gambling man, I suggest you place your money on "TA Performance Extreme Duty V3800 aftermarket block".....at the tune of $4,000 (new msrp, minus prep)

 

[NUTTSGT]

I've seen a few aluminum blocks welded it. Whehter it's a big dollar race block or a small snow blower engine block, it's got the cool factor going for it.

 

[NASTYZEN]

I didn't do the repairs, as its beyond my skill level,
but with the price of this block, I HAD to repair it!
he reconstructed both sides, and heated the block to decrease distortion.
checked align bore afterwards, perfect! cam spins freely too,
I guess you pay for experience.

Wooh. That was major venting. Those are trickier to do without warping. The guys who did it did a nice job of it.Aluminum tends to shrink a lot when welding. The more welding the more the shrinkage. I leave a bit of a gap rather than but up the pieces to allow for the shrinkage.

This was a Formula Ford gearbox spacer that got a little roughed up.

There about 3G's new and 5G's for magnesium ones. So there worth the effort it takes to save em.

They become a little softer or mailable after welding and are harder to brake than original. Voila! Better than new.

 

[NASTYZEN]

I found an ear from a Jim Russel FF2000 block that came off in a spectacular accident in turn one at Tremlant. The funny thing is that I had already fixed this engine block before.
These cars use 2 liter Ford pinto engines or better known as Kents. When they get into a bigger wreck they break the mounting ears that mount the gearboxes to the block. These are cast iron and I use bronze filler to rebuild the bits that were knocked off and re drill holes in them.
If you look closely in the pics you will see cast iron still attached to the ear. It sticks like hell because to rip it off a second time the student lost it big time in that first corner which is down hill and cart wheeled several times making holes in the pavement and finally ripping the engine,gearbox and rear suspension off ,spreading them all in separate directions. We were able to salvage the bits and recycle them one again.
The student bled from his eyes and lungs. Hurt his kidneys and spleen but was ok after some time.

 

[ZTFab]

This was a Formula Ford gearbox spacer that got a little roughed up.

You work on some cool **** NZ.

 

[cruzn57]

Yes, T/A block,
we did have to deck the block,
OH the price of big boy toys! LOL

guy that did this.... does all kinds of trick R&D work for motorcycle factories.
I've seen some major exotic engines at his place, along with gears he cuts for
penske racing , for their transaxles.

 

[nate379]

Well least I was right about it being a Buick

It's aluminum, so that's HIGHLY unlikely. They were cast iron like the rest.


If you are a gambling man, I suggest you place your money on "TA Performance Extreme Duty V3800 aftermarket block".....at the tune of $4,000 (new msrp, minus prep)

 

[NASTYZEN]

You work on some cool **** NZ.

Thank's ZT.I love my job! It all happens in my back yard fab shop too boot.

Yes, T/A block,
we did have to deck the block,
OH the price of big boy toys! LOL

guy that did this.... does all kinds of trick R&D work for motorcycle factories.
I've seen some major exotic engines at his place, along with gears he cuts for
penske racing , for their transaxles.

Like I mentioned before those types of catastrophic failures are tricky to fix. Some one who knows what they were doing fixed it and did a great job. Great jobs come at a price though.

 

[Mario428]

I saw an old B&S vertical that had a hole in the side patches with a small piece of sheet metal, some RTV and 4 self tapping screws. Kept the oil inside !

My engine machinist used to run a Comp Eliminator car, 4 cyl Iron Duke heritage.
He kicked a rod out in Epping, N.H. had another piston rod with him. Put them in patched the block with a sheet metal plate and ran the NHRA Keystones the next weekend. May have been the year he went to the finals there but he would have qualified 1 or 2. He used the block for a while like that. Don't think he ever fixed that cast iron block. He is the kinda guy that will spend days doing something but if it works fine leave it so the block ran with the patch.

 

[NASTYZEN]

Yet another scummy casting from the golf course down the road.

Was able to mount it in the lathe, yea

 

[NASTYZEN]

Nice winter were having here.

This one is a vented truck plow actuator.
Looks like the lug broke first and then the pump went for a ride. No problem.

A little cleanup of the surfaces first is a must!!!

Fitting up a patch.

Tacked in place.

Added some meat to that lug brkt.

Work done.

 

[theoldwizard1]

Tacked in place.

Reminds be of a buddy who patched an old B&S 3.5 vertical that threw a rod through the side. Some galvanized steel, RTV and sheet metal screws !

The crank was "polished" with some fine emery cloth, a new rod was attached to the old wrist pin and piston. It did not have much compression, but it ran for many more years !

 

[ilovevocs]

Very nice work, I always enjoy your posts.

 

[NUTTSGT]

You guys and your weld repairs always amaze me.

 

[bgarrett]

Putting brass on cast iron is nasty. I use a Henrob torch and cast iron filler

 

[NASTYZEN]

Very nice work, I always enjoy your posts.

Thx's!

You guys and your weld repairs always amaze me.

Magic!

Putting brass on cast iron is nasty. I use a Henrob torch and cast iron filler

The lug brkt was Alu. friend
For brass, you may want to check out the Brazing 101 thread in this section.
When I used to have a Henrob type torch. Mine was a Dillon, I would use it mostly for welding Alu. body panels..

 

[NASTYZEN]

Racing season is here again!
These are repairs on a Formula Ford 92 Van Diemen gearbox spacer.

First a little cleanup and die grinder , just like at the dentist.

She's a little beat up.

Burning all the oil out prior to welding. I then re-wire brush everything while it's hot. Then weld.

I usually weld the inside first. That way I get a nicer weld on the outside, where people will see it most.

There. Ready to see the track another day.

 

[NASTYZEN]

Bump.
I just noticed that all blown up pictures in my old threads have been fixed by image shack.
Thought this might be appropriate after you guys all got snow bombed.

 

[steel 35]

Bump.
I just noticed that all blown up pictures in my old threads have been fixed by image shack.
Thought this might be appropriate after you guys all got snow bombed.

Thanks for the bump enjoyed them all, some of these build up pictures make me think of a welding instructor I know, Retired Navy; filling the landing gear groves on decks of aircraft carriers with a spool gun