Replacing Cylinders

[JC85]

After talking to people at Cedar Vale and then messaging with Antietam, I've finally been convinced that the chrome cylinders on my Eldo need to be replaced. $800 is going to hurt A LOT, but considering that I have a matching numbers true police model here, it's worth it to make sure that it stays preserved. I have a couple of questions, though.

First, my dad seems to remember a way to do this without pulling the engine, using a band clamp to get the pistons started into the bore, but cant quite remember. Does anyone know about this?

Second, since I'm replacing the cylinders and pistons, anyways, is there anyone who offers a 1000cc conversion kit? I've heard that there is, but I havent found any.

[Antietam Classic Cycle]

After taking to people at Cedar Vale and then messaging with Antietam, I've finally been convinced that the chrome cylinders on my Eldo need to be replaced. $800 is going to hirt A LOT, but considering that I have a matching numbers true police model here, it's worth it to make sure that it stays preserved. I have a couple of questions, though.

First, my dad seems to remember a way to do this without pulling the engine, using a band clamp to get the pistons started into the bore, but cant quite remember. Dies anyone know about this?

Second, since I'm replacing the cylinders and pistons, anyways, is there anyone who offers a 1000cc conversion kit? I've heard that there is, but I havent found any.

You won't need to pull the engine or use a band clamp. There's a bevel at the bottom of the cylinders that makes it easy to compress the rings as the piston goes into the cylinder.

I'd stick with the standard 83 mm bore - IMO, there's little to gain without breathing improvements (bigger carbs, less restrictive mufflers, etc.).

[JC85]

You won't need to pull the engine or use a band clamp. There's a bevel at the bottom of the cylinders that makes it easy to compress the rings as the piston goes into the cylinder.

I'd stick with the standard 83 mm bore - IMO, there's little to gain without breathing improvements (bigger carbs, less restrictive mufflers, etc.).

Thanks for the info. Another question:

This bike has the Dellorto carbs with the accelerator pump, an air filter modification that allows for better air intake, and the mufflers have had some baffles removed. With those breathing improvements, would it be worth going up in bore size?

[Antietam Classic Cycle]

Thanks for the info. Another question:

This bike has the Dellorto carbs with the accelerator pump, an air filter modification that allows for better air intake, and the mufflers have had some baffles removed. With those breathing improvements, would it be worth going up in bore size?

Standard carbs, K&Ns flow little better than the stock airbox, mufflers maybe a little... I'd still stick with 83 mm bores. A few more reasons:
- 88s will be heavier than 83s, so unless you somehow lighten the 88 piston assemblies (piston, pin, rings, circlips) to match the weight of the 83 piston assemblies or rebalance the crank to compensate for the extra weight, there will be more vibration.
- You may need to alter the pushrod tunnels of the 88 cylinders and/or use T3 onward rocker arms for adequate pushrod clearance.

Neither is insurmountable, just things to consider. 

[brider]

I found it much easier to install the pistons into the cylinders on the bench, leave the wrist-pin hole exposed beneath the skirt, then install the whole she-bang onto the rod and insert the wrist pin.

[Antietam Classic Cycle]

I found it much easier to install the pistons into the cylinders on the bench, leave the wrist-pin hole exposed beneath the skirt, then install the whole she-bang onto the rod and insert the wrist pin.

Yes, that's the way I always do it. I was trying not to overload JC with information.

[Moto]

Am I wrong in remembering that there is machine work to be done on the crankcase to make the 88mm cylinders fit? If that is true, it's one more thing worth considering.

Moto

P.S. I installed the 83mm Gilardonis on my T3 with no trouble, and recommend that. But Charlie has real experience, I think, with the difference in the results you get with 88's vs. 83's, and I don't.

[Antietam Classic Cycle]

Am I wrong in remembering that there is machine work to be done on the crankcase to make the 88mm cylinders fit? If that is true, it's one more thing worth considering.

Moto

P.S. I installed the 83mm Gilardonis on my T3 with no trouble, and recommend that. But Charlie has real experience, I think, with the difference in the results you get with 88's vs. 83's, and I don't.

There are a number of "big bore" kits that come already machined to fit into the Eldorado case and some that have piston assemblies that weigh the same as the 83s.

[Chuck in Indiana]

JC, it sounds hard to do, but it's simple once you get to it. I'd go with the stock displacement, too. The 850 is a little smoother, and there's not much to be gained by going up in displacement without spending serious money.

[brider]

...there's not much to be gained by going up in displacement without spending serious money.

Might just be my perception, but the resale on Loops with the big-bore kit seems to be less, or at least they seem to be less desirable, than the stock displacement. A true Police version would probably remain more valuable as an 850. Something to consider.

[T4halo]

I replaced my cylinders with Gilardoni’s a couple months ago. Worth every nickel. Very easy to do. I’ve put on 600 miles and she runs great.

T4

[JC85]

Thanks for all of the information, guys. This forum really is an amazing resource, and I appreciate all of the help I've gotten from everyone here. I'll be ordering my cylinder kits, tonight, and sticking with the stock displacement. In the meantime, I'll be changing the oil and running it through some fine paint filters, this weekend, to check for chrome flakes. With any luck, there will either be none at all or very little. If there's a lot, then I'll have to reassess, and probably be back for more advice.

[Gliderjohn]

I did the 88s on my T-3 along with much other stuff. Made for a nice engine except a bit more vibration than stock. Yes, to get the most out of it other things need to be done which can get costly. I did the following and the attached dyno run graph shows the results. It is a nice running very streetable motor.
Big block V-7 sport cam.
36mm round slide carbs.
Heads ported and polished.
K&N filters.
Heavy duty valve springs.
I just run cheap Emego Dunstall replica mufflers and they seem to flow fine.
GliderJohn

[Antietam Classic Cycle]

Thanks for all of the information, guys. This forum really is an amazing resource, and I appreciate all of the help I've gotten from everyone here. I'll be ordering my cylinder kits, tonight, and sticking with the stock displacement. In the meantime, I'll be changing the oil and running it through some fine paint filters, this weekend, to check for chrome flakes. With any luck, there will either be none at all or very little. If there's a lot, then I'll have to reassess, and probably be back for more advice.

As I wrote in my PM, worth it to do the magnet test to make sure they haven't already been replaced.

[Chuck in Indiana]

As I wrote in my PM, worth it to do the magnet test to make sure they haven't already been replaced.

Yes. What Charlie says.

[JC85]

As I wrote in my PM, worth it to do the magnet test to make sure they haven't already been replaced.

I did the magnet test, last night, after I read your suggestion. Just forgot to mention it. No go.

[Turin]

I just did my 850T.  I was contemplating getting the 88mm kit, and decided it wasn't worth it. At a minimum, you have to rebalance the crank. Instead I got a deal on a 83mm gilardoni kit with a cracked fin, and put the rest of the money into a good port job. (Already have a Norris s cam and 36 del'lortos) Also bumped compression with thinner base and head gaskets.

[randy yocum]

JC my first Guzzi, a barn find Eldorado had chrome cylinders ,one was losing chrome,I removed the oil pan which isn't hard and examined the screen filter,it was full of chrome flakes and particles.I cleaned everything very good.I replaced the cylinders with cast iron,(this was 20 some years ago)put it all back together,ran it with fresh motor oil for 50 miles,drained and flushed  it once more. I drove that bike another 30.000 miles with no ill effects.I was told that the rod and main bearings wouldn't last but that wasn't the case for me.

[Rolf Halvorsen]

Why is nobody talking about the need of cleaning the sludge trap in the crank-shaft?

[Peter949]

Do all of the Big Block engines still have a 'sludge trap' in the crankshaft? 

[cliffrod]

Why is nobody talking about the need of cleaning the sludge trap in the crank-shaft?

X2. Maybe not mandatory but a good idea.  I did new cylinders and pistons on my V7 Sport long ago without disturbing the bottom end.  Pistons were stuck from sitting, no evidence of flaking in oil pan but didn't know then what I know now. Just did the top end and started riding.  All was good.  About 3 yrs later, the bottom end started growling and required a full service....  Not cool. 

My current V700 project has been off the road for who knows how long and is not even stuck.  but I do it all first this time.

[JC85]

Well, I didnt get the oil changed, today, as I had a lot of cleaning and organization to do in my shop, and got deeper into it than planned. Every time we got one area cleaned up and organized, I found myself saying "you know, that corner, there, has needed this for a while...might as well keep going." It sure looks good in here now, though, so it was worth it.


 



I'll get it changed, this week, though, so I can get an idea of how much flaking is happening. In the meantime, haven't been riding her.

On the plus side, while organizing and shuffling things between the shop and my dad's shed on the property next door, I found his old tank bag with all of the receipts from the engine rebuild his buddy did on it, before it went into storage. Alas, no cylinder upgrade, which I already knew, but now I know everything that was done and should be in good shape. The list is (I'm typing this exactly as it's written on the reciepts):

Oil pump gasket
Front and rear main seals
Piston ring set
Crank plug
Fork seals
New stock cam
Reconditioned lifters
Valve guides
Exhaust valve
Shims - valve spring to head
Reconditioned heads
Set valve spring free length and lap valves
Cores for rebuilt lifters

I also know that the sludge trap on the crankshaft was cleaned out, when all of this was done, and its had less than
2000 miles put on it, since.

[Chuck in Indiana]

^^^^^
Alrighty, now.. new jugs and she should be good to go. 

[JC85]

Well, finally got the oil changed, today. Filtered it through several fine paint filters stacked on top of one another, and I did, indeed, discover some chrome flakes, although they were minimal. So the cylinders will be changed.

Now here's a question: I found two sizable chrome flakes, along with a handful of tiny particulates, but that's all. The one in the photo was the largest. Given that it doesn't seem like the degradation has reached a catastrophic level, yet, I would think that I should be ok with changing the cylinders and then doing an oil change every 500 to 1000 miles to clean out the particulates that have been circulating, instead of having the tear down and flush the entire engine. Thoughts?

 

 

[Antietam Classic Cycle]

There could be much more degradation that you're not seeing - a lot of what flakes off the upper part of the cylinder gets pushed out the exhaust port. But, I think your plan is sound.

Once you remove the original cylinders and pistons, grab each rod and try to rock it fore-and-aft. It'll want to slide slightly on the journal, but try to rock it, not slide it. If it rocks at all, then that's a pretty good indication that the rod bearings and journal are worn and you'll need to go deeper. But, considering the engine was rebuilt less than 2k miles ago, I doubt you'll find any wear.

[Chuck in Indiana]

All I can say is plus 1 to what Charlie is saying.

[dustybarn]

I found it much easier to install the pistons into the cylinders on the bench, leave the wrist-pin hole exposed beneath the skirt, then install the whole she-bang onto the rod and insert the wrist pin.

This is how I did it on my '70 Ambo. I did chill the wrist pins in the freezer before attempting to insert them.

[F-22]

The Gilardoni writs pins aren't an interference fit like the stock Guzzi ones. At least the ones I've installed weren't.

[dustybarn]

The Gilardoni writs pins aren't an interference fit like the stock Guzzi ones. At least the ones I've installed weren't.

That may well be true. I did have to improvise a screw press using a carriage bolt, a nut, and some PVC tube fittings to press the old ones out. I didn't try to insert them at room temperature, chilling the new ones might have been unnecessary.

[JC85]

Ok, everything is here, and I'm ready to replace the cylinders, this weekend. For anyone who has used these lots, though, I have a question. Each kit comes with one totally flat compression ring, and another that has a small groove around the outside edge (see photo.) What us the purpose of this? Since each kit comes with one of each, I assume that they need to be installed a certain way, but there are no instructions. Is one of them supposed to go in the first slot, and the other in the second one? Which way does the grooved one go in? Groove up or down? Any info would be appreciated.