I picked up a spare barrel for my GS project but it needs some work. It's already bored to 40 over and is ovaled & ridged. I was thinking I'd just replace the liner - especially considering it has an all to common crack up one of the bolt holes that I'll repair.
Does anyone of the GS guys/racers have experience doing liners with these barrels? DaveNV? Just hoping to get any tips/tricks, etc. and maybe a good source for replacement liners. (53 long-rod barrel) THANKS
The liner is a push fit into the Alloy sleave i think from memory its 5 thou interferance, if it were me i would bore it as there is a risk of splitting the Alloy sleave when you insert a new liner.
Both cast and austenitic liners are availible (for DB / DBD) and both are used on racing Goldies, cast is cheaper, you pays your money and makes your choice. Though i think only cast is availible for your barrel type.
In the UK a Cast Liner will set you back about £50.00, plus fitting, rebore and piston.
No idea who could help you in the States but here in Blighty there are about four or five people i could recommend.
Thanks Phil - Unfortunately this thing would have to go beyond 60 over to save it so I'm out of boring options. I've replaced sleeves before but nothing quite like this. Getting the replacement in doesn't worry me anywhere near as much as getting the old one out. I was debating what kind of heating/chilling procedure I could use to help break it loose or at least ease the process.
Although admittedly at £50.00 for the whole thing I'd be tempted just to send it to somebody and avoid the hassle.
Will LASCO be able to do this weird stuff? there site shows cylinder "exchange" for $189 - Kinda doubt they got one of these things laying around.
Clipper, the ones i have seen done including my DBD34GS barrel were lightly heated and the a few tonnes were lent on them.
Usual UK Goldie Suspects: Shearwood Pearson Flinty Et al
Roy shearwood is regared as the Pre DB and DBD expert although he does some weird stuff with DBD34GS to make a Short Stroke 350, which are highly regarded.
I am Sure GS Ron can point in the direction of a US machine shop to do the work, if so give Shearwood or Pearson a call, order a new Liner and Piston and get the work done in the States.
Not wishing to tell you how to suck eggs but let the parts supplier know what you will be using the bike for and have a chat about CR ratio's, maybe worth dropping a little lower than your ego thought, i am going to run about 9:1 for green lane work, this is on UK unleaded fuel which is 85% Octane.
I've replaced a few Gold Star cylinder liners over the years. It's not 'rocket science' and you can do in the home shop if you have a suitable oven to heat the barrel.
A story for you: Years ago before I had a shop oven ($35 electric stove) I would use SWMBO's kitchen oven to heat cases to change bearings etc. I was always very careful to wash everything in hot detergent water so as not to smell up The Kitchen. Anyhow ... I needed to change the liner in my GS racer. I carefully washed the barrel first in solvent and then scrubbed it in hot soapy water. I then 'stealthly' waited to heat it up when She was away playing bridge one Saturday afternoon.
I put the barrel in the oven, set the thermo for 300º and went back to the garage. When I came back to the house in awhile, holy crap, there was a smokey haze and strong smell of Castrol R in the house! Oh oh ... I'm in deep dodo now.
So I flung open the windows and took the hot barrel to the shop and pushed out the liner. I then saw the error of my ways. There was a sheen of bean oil and OEM grease between the liner and the muff that my washing hadn't cleaned up. Perhaps, "A word to the wise", on using The Mom's oven?
Anyhow ... I finnished the liner replacement with no problem. Back in the house, I used whatever household fumigant/deoderant I could find and but of course was 'busted' when she got home. I and friends found the scent of bean oil that lingered for a few days to be 'nice'. But 'you know who' thought it was the pits!
Clipper ... You've asked about changing a GS liner. Are you sure a fresh bore won't fix it? As I've mentioned it's doable in the home shop. But as the liner Must be rebored after replacement, an option for you as has been suggested, would be send the pieces to a Trustworthy, Reputable and Experienced shop and have them do it all. Caution: You don't want to deal with, "Gee it wasn't our fault it didn't work out"!!
Something to think about ... Those old BB and Clipper cylinder muffs are well know to develop stress cracks. Evidently the castings were quite thin. I dunno. Because of this friends tell me there's a worldwide shortage of good BB cylinders. Perhaps someone is making new modern replacements? Anyhow .. a caution if any welding is done to a cylinder, insure the muff is heat treated to relieve stress and regain strength messed up by welding.
A muff that has been cracked and welded should be bored true and a over size OD liner installed. I've not tried that. Phil Pearson makes replacement austentic liners and I would guess he could do this operation. ??
Personally, I've sold my cracked and welded up and recracked POS cylinders to a "It will be OK", swap meet, "Buy it Cheep", dreamers. In the case of DBDs, damaged cylinders are generally the result of the dreaded broken rod blow ups. In my opinion, Life is too short and Goldies too nice to use crap pieces when there are good DBD cylinders available new and used.
I've found it interesting that heating the barrel releases the liner quite easily in my limited experiences. Being made of austentic (sp) steel, vs common cast iron, the GS liner's high expansion rate still allows a snug but slip fit when heated. Being a bit paranoid of a liner being cocked or stuck part way in or out, I've come up with a few ideas for my use. You are messing with a very hot, expensive and awkward lump doing this job.
I had a friend lathe a disc of thick alu with the small diameter to spigot into the liner and a shoulder that will catch the ends of the liner. I use this to both push the old liner out and the new one in.
I made a wooden open ended box using short lengths of 2" x 8" lumber screwed together. This gives you something to rest the hot cylinder on for both removal and installation of the liner. Using the end of a hammer handle tapping against the alu disk inserted into the liner, the liner comes out OK. I've set up to use my shop press for this but haven't needed it. YMMV.
Smear heavy grease on the OD of the new liner. This both acts as a lube when pressing it in and also helps heat conduction from the liner to the muff in operation. Now plastic bag the greasy liner and put it in The Mom's freezer for a good chill to shrink it. Reheat the muff and position it on wooden blocks or the 'box' I've mentioned. Natch you need clearance on the bottom of the muff where the liner protrudes.
Important: You will need something quite heavy to set on top of the new liner after it's installed and cooling to prevent the liner from 'creeping' up. I use my heavy old shop anvil made from a piece of railroad rail.
If your head gasket leaks or pukes the first time the engine is run and gets hot, you'll know the liner wasn't set properly and "creeped", when it cooled. BTDT, got the shirt one morning breaking in a fresh engine with a race that evening. Luckily I had a gasket and got it fixed and running in time, but I really hate such sh!te. aarrgh.
Now ever so carefully so as not to cock the liner, quickly insert it into the muff and push/tap it down. Keep in mind the hot muff will quickly heat the chilled/shrunk liner doing this. You don't want it stuck part way. ooohh. Now quickly put the heavy weight on top of the liner flange and let things cool. "There ya go, Bob's yer uncle".
Thanks for links Phil, I'll bookmark Shearwoods as I didn't have his info. No need to suck eggs here-I'm already staying nice and low on my CR, I've got 9:1 piston going in. This is going to be a nice calm go-about-town Goldie. I'm not trying to keep up with DaveNV yet! & without switching to one of Pearson's cranks I wasn't going to consider upping CR at all. I really just got the barrel for a song and was hoping to resurrect it-I like the idea of a spare.
Dave-NV, I did the same thing too many times and finally got sick of setting the smoke detectors off! I picked up a little electric heat treating oven (a little double oven, about 2 cu. ft ea.) - Granted I still get the shop all smokey but at least my furniture doesn't stink for a week! And I can throw the occasional part in there if I want to harden.
Anyway, it doesn't sound like it comes out that hard. I was debating if I should heat the cylinder 1st and then throw some dry ice inside the barrel, but it doesn't sound like I need to.
I'm 99% sure a bore-job isn't going to do it. I ran the bore gauge through it and judging by the amount of rust and oval wear in the bore I don't think an add'l 20 over is enough. I could always set it up and bore it first to see if cleans up enough I guess. Couldn't hurt, eh?
This one definitely has the stress crack problem. So far it only has one and it reaches about 1/2 way up the left side of the casting. (Another reason I got it so cheap.) But like you said, there's quite a shortage of these small fin cylinders & that's exactly why I'm trying to save the silly thing. I spoke with a A-Clipper owner who insisted his had been cracked for years and never went anywhere but it still makes me nervous.
ABSAF in The Netherlands has been working to start reproducing them, but as of the last I knew they hadn't gone into production yet. Some days I wish I had a DBD, it would make sourcing parts quite a bit easier.
I was planning to make an alum. disk to press it out just as you described. I was actually planning on using the shop press for the task - I'm thinking leaving it set in the press with just a bit of force on it should be enough to keep it from creeping? The only risk I see with using the press is TOO MUCH force...
For the Price of a rebore it maybe worth trying a cut to see how it goes, i am sure you can pick up a piston measure it and try.
I do know there have been some +80 pistions made or sourced from a different vehicle but i am unsure if they were DBD use or not.
I spoke to ABSAF a month or so ago and they were taking or thinking about taking orders for the BB barrel so it maybe worth giving them a call, if all else fails they will have liners that will fit you alloy sleave.
Just to let you know i was building a long conrod motor and got so fedup looking for parts i changed it all to DB / DBD as i could get the bits. Though if you have a DBD head i know people who may swap it for a BB barrel and head, funny old world.
Sorry for the delay... OK the BB and ZB cylinders are not as robust as the DB / DBD. Yes they easily crack at the 4 spots where the short head bolts go... Also the liners are very thin.
The original Austenitic liners are stronger than cast iron.. if you use a cast iron liner, you risk cylinder cracks.. beware bewarned.. been there, done that...
Good news, is that Pearson can supply the proper (longer) Austenic liner to fit. Phil also has a premium welder he uses Nick Paravonti, who fixed my BB cylinder when I cracked it.. I dare you to find the repair..!
To remove the old liner head the **** out of it..! 350 to 400 degrees... make up your "pusher plate, and go for it.. once it starts moving don't stop... if you are using a press, make sure you have enough travel before you start... Keep in mind that the Austenitic was used used for more than one reason.. first it is non-magnetic, a sort of "stainless" steel.. much harder than cast iron, plus it expands more than normal steel it order to try and keep up with the alloy muff.
Once you have the old liner removed, let it air cool.. then have the "bore" checked with a bore guage. If it is way out of round, have it lightly bored... yes this makes it weaker but not as bad as pushing a round liner back in... Then call Phil and have him make a liner to fit.. Use the same process to put the new liner in... heat until HOT, chill the liner, press it in, leave it in the press until it cools...
I just bit the bullet, and paid the shipping to Phil.. had him do all the work.. those early cylinders are getting hard to find...
Ron ... Thanks for sharing the info on your BB GS cylinder repairs and experiences which directly apply to the questions Clipper has asked.
Gents ... Ron doesn't just 'putt' his BB34GS as some riders do, but rides with a 'big throttle'. Tune in, build it right and you too can let your Goldie Sing as was intended by those Guys in Birmingham. I've followed him on his BB up/down and around many Twisties over the years and his GSs run strong and fast.
As always, your expertise and experience is greatly appreciated!
I'll let you know how this monster comes out. & as an aside, the bike should have the finishing touches on it later this summer (after 3 mildly distracted years of working on it). If I ever figure out how to work my digital camera I'll post some pics of it....
Well, after taking it to 60 over it was clear that more was required. I still had some nasty scoring on one side.
I have to say I was surprised how easy the thing came out - I threw it in the shop oven @ 375 and got it nice and warm (filled the shop with smoke of course ). I made a plate out of some scrap 1/2" steel to set the barrel on and hold it steady in the press. The disk to push it out I turned out of some 2025 alum stock.
With everything set-up and ready to go I pulled the cylinder from the oven (with some very nice floral pattern oven mitts-BTW) and ran to the press. It pushed out clean and easy
My brother is a MUCH better welder so I had him take care of the crack. He welded it up before removing the liner....the **** broke a fin in the process but repaired it Beautiful work though. Now I may get chastised for this...but after getting the old liner out & checking with a bore gauge & inspecting closely the casting check out true and smooth so I didn't bore it. I'll take my beating now.....
I had tracked down a cast liner (had NO luck trying to get an austenitic one) and pressed it in using the reverse procedure. Slick, no problems & after cooling bored to stock. Even easier than replacing valve guides.