porous casting repair

[Don G]

There is a casting flaw on my V700 crank case in the main oil journal of course, I noticed that the oil light would come on at hot idle and go out with an RPM increase, I figured that maybe a bad sender was the cause. I sourced a proper fitting and installed a test gauge, I have 10LBS pressure with cold 20-50, so I pulled the lump out and stripped the front cover and oil pan off. I blocked off the oil pick up drilling and induced oil pressure into the sender hole. I found that there was a mass leak behind the cam gear.
Now I wonder about a fix for this casting flaw, I am not even considering welding , perhaps an aluminum based epoxy would be the best, anyone with any practical experience out there?

[John A]

I'd look at drilling and tapping for a plug if that's suitable. Otherwise a Devcon or similar product if you can get the oil cleaned out of the pores by heating and a solvent like MEK followed by acid etching.

[JoeW]

I've repaired porous cases with JB weld BUT, that's a pressurized passage. Drilling and tapping could work, you'd have to at least pull the front main and oil pump to make sure you get all the filings out. That hole looks pretty big, who knows how big the fissure really is. I would think the best repair would be welding.
I have a spare v700 case number #1885.

[Zoom Zoom]

Looking at the first pic, and noticing the small pin holes around the big hole, I would be concerned about any repair. The entire area looks thin. I could just see a repair failing and then you are back to where you started or worse.

Have you considered submitting these pictures to a dealer just in case Guzzi is willing to cover this. There is no doubt this is a casting flaw. It can't hurt to ask.

John Henry

[John A]

I would personally not weld because I'd be worried about distorting it. Maybe a welder can give a better estimation. You could just call Rodekyll and buy a good block. After looking at the pictures closer, I'd clean it, heat it, clean it, etch it and seal it.

[Antietam Classic Cycle]

Looking at the first pic, and noticing the small pin holes around the big hole, I would be concerned about any repair. The entire area looks thin. I could just see a repair failing and then you are back to where you started or worse.

Have you considered submitting these pictures to a dealer just in case Guzzi is willing to cover this. There is no doubt this is a casting flaw. It can't hurt to ask.

John Henry

I would think that the warranty has long ago lapsed on a V700. 

I will be parting out a '67 V700, so if a replacement case is needed, I'll have one.

[Zoom Zoom]

Well yeah. I was thinking it may be a modern V7(00)

It it is as you suggest Charlie, I personally would go looking for another block and be done with it.

John Henry

[Kiwi_Roy]

https://thumb.ibb.co/inY3nd/IMG_0145.jpg[/img][/url]

It appears the oil way goes from the center of the upper shaft to the center of the lower one, this would have been drilled after casting.
Could you strip it down and drill the oil way larger and then insert a sleeve? I'm thinking something like the thin walled steel tubing used for brake lines.

I would try stuffing something in the hole first, it doesn't have to be perfectly oil tight, similar to the lead plugs you see in carburetors.
It looks as though the flaw would be at the back of the oil-way, it might be safe to drill it without having to pull it all apart. The rougher the better if you want to try epoxy.

Really, how many years has this motor been running in this condition, it's no big deal to run low pressure at idle. My Eldorado will drop below 10 psi when it's really hot, idles below 800 at a guess back at 60 when moving.

BTW, none of my earlier Guzzis had a reliable oil pressure switch, I put a gauge on.

[AJ Huff]

 that's a scrap casting. Should never have made it past QC. No real fix. Sorry.

-AJ

[Don G]

Yup, a new case is in my future, it looks pretty thin, that's why I didn't want to weld the hole closed, if it was cast Iron I wouldn't hesitate to braze it shut but aluminum is a different story, could be a disaster. I wonder if this has leaked from day one? I was road testing this engine after a complete overhaul and was wondering why it seemed to run hot, timing was on and had new springs in the distributor and jetting was correct, now I know why! I may take the case into the local Tig welder and get an opinion, but I think I may be contacting the chaps with the spare cases on offer, thanks guys!  DonG

[RinkRat II]

 I agree with Kiwi Roy, if it's accesible to drill and sleeve that would be the most permanent fix. After you talk to your welder, talk to a machine shop and see.

   Paul B

[Wayne Orwig]

Drill it. Thread it. Loctite a tiny grub screw in it.

[Perazzimx14]

Yup, a new case is in my future, it looks pretty thin, that's why I didn't want to weld the hole closed, if it was cast Iron I wouldn't hesitate to braze it shut but aluminum is a different story, could be a disaster. I wonder if this has leaked from day one? I was road testing this engine after a complete overhaul and was wondering why it seemed to run hot, timing was on and had new springs in the distributor and jetting was correct, now I know why! I may take the case into the local Tig welder and get an opinion, but I think I may be contacting the chaps with the spare cases on offer, thanks guys!  DonG

Since the block is no good as is you can't ruin it further by try to repair it.

[Rough Edge racing]

 Hmmm, that does look cheesy when the photo is enlarged.... If possible, my hillbilly repair would be a small patch from aluminum sheet metal formed to fit with a few perimeter screws...And a high quality epoxy as a sealer between patch and casting...

[larrys]

I have an Ambassador block that I would let go, would that work?
Larry

[Kiwi_Roy]

The problem with changing the block is the engine No will no longer match the frame.
Assuming it did anyway.
My loop has the same No
What's the mileage on the odo?

[Don G]

Yeah the frame and engine #'s match on this one, I have another 68 model and they also match, one other one that I have does not.  DonG

[Antietam Classic Cycle]

The problem with changing the block is the engine No will no longer match the frame.
Assuming it did anyway.
My loop has the same No
What's the mileage on the odo?

V700 numbers rarely match from the factory, so it wouldn't be a big deal. The '67 I'm parting out has engine number 1566 and frame number 1433. Ambassadors and Eldorados almost always do.

[Chuck in Indiana]

Yeah the frame and engine #'s match on this one, I have another 68 model and they also match, one other one that I have does not.  DonG

I wouldn't be afraid to weld it. The problem will be getting the casting clean enough to weld. That means a tear down, I'm afraid..

[Toecutter]

Why aren't you thinking of welding? Seems like the most logical choice.

[JoeW]

That passage is accessible through the port from the bridge pipe. That is an 8mm hole, the leaking passage is 5 mm. A skilled machinist could open it up to accept a sleeve. I would not drill all the way to the cam bearing surface so the sleeve has an upper stop. Just an idea.

[Kiwi_Roy]

That passage is accessible through the port from the bridge pipe. That is an 8mm hole, the leaking passage is 5 mm. A skilled machinist could open it up to accept a sleeve. I would not drill all the way to the cam bearing surface so the sleeve has an upper stop. Just an idea.

"Sure, bring it on over, I'll take a look"

[Antietam Classic Cycle]

That passage is accessible through the port from the bridge pipe. That is an 8mm hole, the leaking passage is 5 mm. A skilled machinist could open it up to accept a sleeve. I would not drill all the way to the cam bearing surface so the sleeve has an upper stop. Just an idea.

 

[Don G]

Good plan Kiwi & Joe, I will scope it out tonight, just have to find some tubing..... DonG

[Kiwi_Roy]

Thin walled steel brake lines is what I used on my Eldo, the car parts places usually have short pre-made lengths, just drill out with a pistol drill to suit, I don't believe the 5mm is critical, 1/4" OD perhaps.

[JoeW]

Mcmaster Carr part number 9811T13  8 mm OD 5 mm ID seamless stainless tubing. .5m is $56.00

[canuck750]

Hi Don

I have a set of alpha numerical stamps and the star stamps as well to replicate the factory engine stamps, not that I am encouraging any fakery but it is a Loop motor after all and not something as rare as a V7 Sport or Le Mans. If you get a replacement block bring it over and we make it into a matching numbers block

[AJ Huff]

Look the whole casting over. That's a shrinkage defect. That heavy section was feeding the thinner section and there wasn't enough metal at the end of solidification to keep the heavy section full. You might want to make sure you don't have any more where you have a heavy section to thin section intersection, same side of the casting.

-AJ

[JoeW]

I had a persistent oil leak on an Ambo recently. It wasn't a pressure leak just gravity. I found it with baby powder. And fixed it with JB Weld.

Sent from my VS988 using Tapatalk

[JoeW]

Thin walled steel brake lines is what I used on my Eldo, the car parts places usually have short pre-made lengths, just drill out with a pistol drill to suit, I don't believe the 5mm is critical, 1/4" OD perhaps.

I disagree, this passage feeds the front cam bearing and the rockers. I would try to be as precise as possible. 8 mm is .3150" 5/16 is .3125 that would be a decent interference fit. I would prefer doing it in a mill or a good drill press at the very least.

Sent from my QTASUN1 using Tapatalk