XLCH/XLR Hybrid build

Classic short-frame models

XLCH/XLR Hybrid build

Postby xlh59 » Sun Jan 09, 2022 7:29 am

Hi to All,
I think the time has come to give you an update on my long-term XLCH/XLR project. It has been a hard time and when I bought this project I was definitely not aware on how complex and time consuming this would get. Still, I am very happy that I took the chance to buy this project quite some time back. I have hinted at this project in one post or another, now I want to document the process and present first results. First I will write a rather long text, later I will add the respective pictures.
This forum had provided me with vast amounts of information, so a big “thank you” to all of you. I will post a similar post in the XLForum, as this forum was also a big resource of information for me.

So what are we talking about?

This is a classic “basket case” – completely in bits and pieces – that I bought about 14 years ago. Why did this project take so long? This is easy to explain: the bike is not an “off-the-shelf” vehicle, but rather a heavily modified racing model. So I was missing the classic repair manuals, exploded views or sources for spare parts. Many missing or broken parts had to be repaired (which you wouldn´t do with “std” parts) or newly manufactured. Apart from that I am hobbyist with family, hence limited time. About 5 years ago I thought I was ready for the final assembly ... far from it. I was on the verge of giving up this fall, after the Linkert DC cracked while cleaning.
Within the last years I have moved twice between continents and thought the basket is the perfect puzzle to keep wrenching during that time. It was a good idea, but the supply situation on site was significantly worse from what I had expected, so everything was additionally slowed down. At least I am very happy with the paint job, which was done abroad. Due to very restrictive regulation in regards to “road legal” in Germany I left the original frame in Germany and took an early XL frame with me. I just didn't want to risk any trouble with the original frame. Therefore, the XL frame can be seen in some of the pictures, which is not the original frame.

Let’s talk details:
We are talking about an early XLRTT chassis (probably between 1960 and 1962, unfortunately the seat casting has been “lightened”) with a '59 XLCH engine. The engine cases have been (at some point) completely rebuilt to XLR specifications, so it’s a full ball bearing, technically XLR engine. However, the engine is still far from a "stock XLR" as it is a big-bore stroker.

The engine:
The cylinders are made of aluminium, have 3 ¼ bores and are 0.220“ longer than standard cylinders. The flywheels with the bike were heavily shaved KH (4 9/16”) with shafts grinded to fit the main ball bearings – this results in about 77cui. I ordered XLR flywheels from T&O with KH stroke and the right tapers for the existing shafts. The pistons were custom-made from the German company “Wahl” which also supplies the pistons for historic factory race cars (Porsche, Mercedes etc.). Dr.Dick helped me a lot with this (thanks again) and “we” decided to for a static compression of 9.3:1, given the overall engine configuration. The connecting rods and crank pins are also the big -55R version, much more massive as normal.
The heads had been substantially ported in the past, so I cleaned up everything carefully and had a new valve job done with the respective tulip “R”valves. Valve springs are Manley heavy duty and camshafts are Sifton Hustler with the “R” ball bearing shafts. I can tell you that these shafts were a nightmare for itself. The gearbox has an OEM HD close ratio transmission (not Andrews) with the corresponding 25mm ball bearing on the output side. No special features on the primary side despite the noisy gear type primary chain tensioner. The engine came with a ¼ speed "R" oil pump, but I replaced it with a -72 pump – somehow I felt this is the better option for the road.
The engine and the chassis have both several mysterious wholes bored, not all of them make sense to me. It took me a long time to understand the sense/nonsense of the screws in the cam cover, especially as all parts came in boxes. Actually they are used to adjust the axial play of the camshafts.
A particular frustration almost at the end was the Linkert DC-11 carburettor, which I reported on lately.

The frame:
Luckily, the chassis was rather straight forward. I exchanged the original Ceriani / Arces triple clamps, as in combination with the steering head angle, they resulted in a very short trail of 3.125” with the selected 3.25x19” front tyre. Sure, “short” is good for the track, but I want to use it on the road as well. I found suitable bridges from an Aprilia, with steel bottom triples and the correct vintage look. The trail now is a precise 4”, which seems to be a very good compromise (to be verified). The wheels have the large -54R brakes and the -60 aluminium high shoulder rims. The shock absorbers are the classic "high road clearance" dampers with aluminium sleeves. A normal 7/8 "handlebar was and is installed, but I am looking for an option to convert this to 1" handlebars ... looks more authentic in my eyes.
The tank and fender are XLCH parts, but with the aluminium “R” fender struts. The basket came without footrests, so I'm not 100% sure which approach I should go for. I like the left peg mounted to the steel primary cover, but the cover on the pictures is from a different bike. I'm also working on a special solution for the seat, as I hate the solo seat for driving. It doesn´t allow you to “move” on the bike. The oil tank is made from aluminium and of course the bike came with XLR drag pipes ...

Starting:
I reported about my difficulties with engine starting, which destroyed my plans to have a victorious “first start” video recorded. Anyway, the engine is generally difficult to turn over by kicking, probably due to a mixture of initial tight tolerances after the rebuild and the light flywheels. For now I can start the engine with a few kicks when cold. If warm, I have not found the correct mix of settings (throttle, prime kick and choke plate). I also noticed that the engine needs a bit more throttle when starting to drive in first gear than with my stock XLH engine.
Once the engine is running it sounds quite "mean" ... it reacts instantly on any twist of the throttle whilst having an incredibly healthy sound. The engine is of course “noisier” than my stock XLH, but a lot of the noise seems to come from the primary chain tensioner.
xlh59
 
Posts: 125
Joined: Fri Oct 27, 2017 2:12 pm
Location: Germany

Re: XLCH/XLR Hybrid build

Postby xlh59 » Sun Jan 09, 2022 7:34 am

This is how the basket looked, when I shipped it as private puzzle abroad:
P1090010.JPG
P1090010.JPG (246.31 KiB) Viewed 19481 times


This is how it was transported back to germany five years later:
IMG_20170704_124134833.jpg
IMG_20170704_124134833.jpg (412.1 KiB) Viewed 19481 times


During the first transport the engine cases got a very disturbing crack which needed to be fixed:
IMG_20160816_083819658.jpg
IMG_20160816_083819658.jpg (432.81 KiB) Viewed 19481 times
xlh59
 
Posts: 125
Joined: Fri Oct 27, 2017 2:12 pm
Location: Germany

Re: XLCH/XLR Hybrid build

Postby xlh59 » Sun Jan 09, 2022 7:38 am

Some of the engine internals:
045.JPG
045.JPG (243.3 KiB) Viewed 19477 times


flywheels:
IMG_20190216_145431_843_small.jpg
IMG_20190216_145431_843_small.jpg (220.97 KiB) Viewed 19477 times


as the flywheels were to light at the bottom to be correctly balanced, I needed to add mallory plugs (which I really would have preferrd not to do)

camshafts:
Sifton Cams.jpg
Sifton Cams.jpg (97.19 KiB) Viewed 19477 times
xlh59
 
Posts: 125
Joined: Fri Oct 27, 2017 2:12 pm
Location: Germany

Re: XLCH/XLR Hybrid build

Postby xlh59 » Sun Jan 09, 2022 7:43 am

Ball bearings or similar sized rollers. I opted for the XR left main bearings and rollers on the right side.
IMG_20160902_222412930.jpg
IMG_20160902_222412930.jpg (464.61 KiB) Viewed 19477 times


IMG_20160902_222400856.jpg
IMG_20160902_222400856.jpg (457.94 KiB) Viewed 19477 times


IMG_20210226_225917_038.jpg
IMG_20210226_225917_038.jpg (212.46 KiB) Viewed 19477 times


the retainer for the ball bearing wouldn´t fit anymore, as the XR barrel bearing is wider than the original ball bearing. So I needed to machine a special one ...
xlh59
 
Posts: 125
Joined: Fri Oct 27, 2017 2:12 pm
Location: Germany

Re: XLCH/XLR Hybrid build

Postby xlh59 » Sun Jan 09, 2022 7:46 am

More headwork ... pistons:
P1100920.JPG
P1100920.JPG (237.58 KiB) Viewed 19477 times


checking valve/piston clearance:
IMG_20210626_234813_145.jpg
IMG_20210626_234813_145.jpg (258.12 KiB) Viewed 19477 times


the spacers instead of springs -- here made of brass (I think they were originally aluminium?)
IMG_20210505_223331_658.jpg
IMG_20210505_223331_658.jpg (319.02 KiB) Viewed 19477 times
xlh59
 
Posts: 125
Joined: Fri Oct 27, 2017 2:12 pm
Location: Germany

Re: XLCH/XLR Hybrid build

Postby xlh59 » Sun Jan 09, 2022 7:49 am

The frame had definately a life before:
IMG_20190111_190813_865.jpg
IMG_20190111_190813_865.jpg (243.09 KiB) Viewed 19476 times


really inspiring was the fine sand in the top tube, which was several inches thick:
IMG_20190125_185415_607.jpg
IMG_20190125_185415_607.jpg (231.87 KiB) Viewed 19476 times


the wheels with new tyres:
IMG_20190123_175619_834.jpg
IMG_20190123_175619_834.jpg (313.87 KiB) Viewed 19476 times
xlh59
 
Posts: 125
Joined: Fri Oct 27, 2017 2:12 pm
Location: Germany

Re: XLCH/XLR Hybrid build

Postby xlh59 » Sun Jan 09, 2022 7:51 am

The paint job:
IMG_20170417_170153361_HDR.jpg
IMG_20170417_170153361_HDR.jpg (481.99 KiB) Viewed 19475 times


IMG_20170422_115202811_HDR.jpg
IMG_20170422_115202811_HDR.jpg (459.9 KiB) Viewed 19475 times


An a first assembly of parts ...
IMG_20201015_234710_568.jpg
IMG_20201015_234710_568.jpg (319.71 KiB) Viewed 19475 times
xlh59
 
Posts: 125
Joined: Fri Oct 27, 2017 2:12 pm
Location: Germany

Re: XLCH/XLR Hybrid build

Postby xlh59 » Sun Jan 09, 2022 7:53 am

engine looks good!
IMG_20210130_234953_927.jpg
IMG_20210130_234953_927.jpg (340.49 KiB) Viewed 19054 times


engine in frame:
IMG_20210712_223821_760.jpg
IMG_20210712_223821_760.jpg (290.56 KiB) Viewed 19475 times


moving from the basement to sister XLH:
IMG_20210825_231410_296.jpg
IMG_20210825_231410_296.jpg (291.41 KiB) Viewed 19475 times
Last edited by xlh59 on Fri Jan 14, 2022 3:41 pm, edited 1 time in total.
xlh59
 
Posts: 125
Joined: Fri Oct 27, 2017 2:12 pm
Location: Germany

Re: XLCH/XLR Hybrid build

Postby xlh59 » Sun Jan 09, 2022 7:57 am

Final details -- reproduction of rear brake bolt:
IMG_20210615_221445_785.jpg
IMG_20210615_221445_785.jpg (135.74 KiB) Viewed 19472 times


Oil line wires -- sorry for the green coating:
IMG_20211029_124520_897.jpg
IMG_20211029_124520_897.jpg (223.3 KiB) Viewed 19472 times


the longer plates for the pushrod tubes -- I really hate the stock "srewdriver approach" so I added something for better handling:
IMG_20211111_000421_176.jpg
IMG_20211111_000421_176.jpg (288.58 KiB) Viewed 19472 times
xlh59
 
Posts: 125
Joined: Fri Oct 27, 2017 2:12 pm
Location: Germany

Re: XLCH/XLR Hybrid build

Postby xlh59 » Sun Jan 09, 2022 8:13 am

And here first time, the engine was running -- unfortunately no heroic "first start -- three kicks" video :D

https://youtu.be/i1U3Jrw7rjM
xlh59
 
Posts: 125
Joined: Fri Oct 27, 2017 2:12 pm
Location: Germany

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