Thinking about the Hydro engine and recalls.

[Tom H]

Let's say you find a perfect looking Hydro with only 200 actual miles on it. No recalls have been done. You buy it fully knowing that it could be a disaster.

I am only wanting to talk about the engine. The triple tree is a different issue.

Now you have pulled the pan and front cover. You pull the oil pump and it's perfect. You look in the pan, clean. Look up at the cam and all, no issues. But....We know we can't just hop on a ride a billion miles on it just yet. So....

IIRR, the main issue was the valve springs. Changing them to Loop Eldo springs was one of the fixes. I also think that the tappets had a coating issue????? Right or wrong on the tappets?? I think the cam had been found to be fine if it was undamaged. Did it NEED to be replaced if undamaged??????

I know that the latter kit had the cam, tappets, lifters, rockers, valve keepers, springs, front cover gasket and a oil pan gasket IIRR. If it was again, an undamaged engine (let's say still on showroom floor) did it REALLY NEED all the parts??

I love my fixed '04 engine!!!
Tom

[Tom H]

rodekyll, now you got me thinking. Uh Oh!!

All,

The cam....So it was too soft as well as needing holes drilled for oil. Think I got it. But.....Your saying the holes were drilled at the wrong angle on the first drilled ones? As in from a flat surface, they drilled 90deg when it SHB 45deg FOR INSTANCE?

The cam again..... Many moons ago, I think someone told me that the cam lobes were not the same diameter across the lifting face. If you measure from the back of the lobe to the lifting face on one end of it, it would be X, now move to the other end of the lobe and it would be Y. I was told this was to rotate the tappet. Was this wrong?

I do understand trying to rotate the valve train parts. My old BMW Airhead, the rockers are supposed to be offset on the valve to rotate the valve.

Tappets...I thought they would have been flat faced. They should have had some sort of cone shape to the face to help them rotate?

Timing chain tensioner....On MY '04, I had to stay with the stock tensioner or do some machine work to fit the Valtec style. There is a "shelf" that the stock tensioner sits on. The Valtec would not work with this "shelf". It would have had to be removed. I think?? Huzo did remove one to fit the Valtec???

Thank you so far!!!
Tom

[Tom H]

Now let's say I have this engine sitting on my bench. I can't get a "kit", but I can order parts at my local dealer or an internet source.

I or the dealer look up the part list for my bike. We order the "needed" parts......

Would I get the updated bits or would I get the original parts from before the recall??????

We all talk about the "kits" that are hard to find. I am really curious if the "bits" that are currently available are the new correct parts???

I'm not trying to ask a stupid question here. There are Hydro's that have not been "fixed". If a new owner needed to fix one, it would be nice to know it the parts, not kit, could be had.

Thanks again so far!!!
Tom

[Wayne Orwig]

Worst case, I suspect that if you changed out the valve springs on a low miles hydro, that alone would likely prevent the failure.

They did change the cam to different oil oils, but they still failed.
They did add shims to the plunger to reduce the clearance when it leaked down, as the recall kit has the adjusters. But they still failed.
I don't recall and coating or hardening of the tappets (like they tried in the 8V motors).
Most of the 'magic' was in the spring change.

My hydro had over 30,000 miles on it, when the kit was put in. There was no wear that I noticed. So it must have had good spring in it.

[John Croucher]

I don't know if the cams were soft or hard.  But they were wrong.  The oil holes were moved between the two recall versions.




comment image


Here's what the recall kit looks like.






This is a properly snapped off valve adjuster.





I have no idea what you'd get if you tried to buy the bits.  Greg Field out of Seattle was a parts counterman for Moto International during that era, and he wrote some books on Guzzi.  He may have that information.  Guzziology might also address it in one of the later revisions.  I've only bought kits, and haven't had the need for additional parts since.  Maybe some of the shop mechanics here can help.

There's a shared geometry between the cam lobe and the tappet.  Yes, it's to aid in spinning.  Different engines have different geometries and I don't know what Guzzi did there.  I do know that the cam and tappets come as a set.  Again, Guzziology might discuss it.

I can't speak to the tensioner issue, either.  I put timing gears in mine.   

Some where here on WG it was mentioned that the cam was not case hardened properly after forging and then when the grinding took place the thin areas of case hardening was ground off.

The cam was made by Crane Cam in the U.S.A?  Something else I read hear.

Oiling is an issue on the rocker arms and valve stem end.  As mentioned and I had never heard this before, a high/larger vane oil pump is needed to make up for the leaking tappets.  I have taken three of these engines apart with around 20,000 miles.  All had worn rocker arms and grooves worn in the end of the valve stem.  Another symptom of the low oil flow would be head cooling.  I you pull the valve cover off, You will see that the head on the exhaust side has a lot of burnt oil on it from the head not getting more cooling oil flowing over it.

The valves can and shoot be adjusted.  Basically like the solid lifter engines.  Top dead center, loosen the nut and screw, turn the screw in until it touches the push rod and then 1-1/2 more turns in.  Tighten the lock nut. 

Do you know the part number or source of the better oil pump?  I would like to replace mine.

I abuse my engine regularly.  I put a set of high compression pistons from a Sport Guzzi engine in the bike.  What a huge difference it made.  Along with a Ram clutch.  I would like to twin plug the heads, but those that say They can do it are lying and can't.  I have sent them around the world over a two year period and got them back with out ever being twin plugged.

 It will most likely outlast my riding days.  If it breaks, I have a newly rebuilt engine sitting on the work bench.

[Bpreynolds2]

If you are looking at a Hydro you may also possibly be looking at a single plate clutch issue as well depending.  Just saying.  Mine went out on one Cali owned with only 1400 miles on it.  Seriously. 

[Tom H]

I didn't think about the clutch issue. The clutch is a pain to pull and change, but the parts can be had. The engine parts are what really makes me wonder what I would get if I ever needed to order one of the special Hydro parts.

MG Cycle still has what they claim to be a  upgraded/higher flow oil pump. When I did buy one for my Hydro, there was an issue with the key way in the batch they had at the time. I'm sure that has been addressed. The pump looked great, I probably should have had a machine shop cut the key way correctly and kept it.
https://www.mgcycle.com/index.php?main_page=product_info&cPath=68_162&products_id=1985

It's starting to sound like if you have an undamaged very low mile Hydro. You might be able to get away with just a cam, tappets and valve springs. A high flow oil pump would be nice as well.

I know there was a design change on the hydraulic lifters, I don't know if the new design did anything to fix the issue?

Thanks again so far!!
Tom

[Bpreynolds2]

It's starting to sound like if you have an undamaged very low mile Hydro. You might be able to get away with just a cam, tappets and valve springs. A high flow oil pump would be nice as well.

See, I think we must have extremely different ears  and that’s not a criticism but what it’s sounding like to me is that you’d be far better to buy a hydro with the clutch and recalls done already.   

[Tom H]

I agree, one that has "all" the correct fixes would be the way to go!

But....If you found a perfect one at the right (dirt cheap) price and didn't mind a bit of work. Could it be done without a kit and what was "really needed" to fix the engine.

As far as the tool set. From what I understand, most of the tools just made it quicker to do the job. For instance, the tool that you use to remove the tappets. Can't you just reach in from the oil pan and exchange them? The tool that compresses the valve springs would be nice, but you could pull the head to remove the valves and springs with a standard compressor. At least at home this is an option, maybe not for a shop.

Tom

[Tom H]

I looked at the kit price. Glad I was sitting down. Who would ever buy it??

Let's say you found the Hydro of your dreams, 200 miles on the clock with perfect paint and chrome. The owner is having a hard time selling it because of the lack of the recalls being done. He sells it for let's say $500. You buy the kit and do the work and now you have a perfect low mile bike for let's say $4000. That's not too bad??

Tom