'64 BSA Lightning Rocket - Carburetor Rebuild

I was pleasantly surprised that the Lightning Rocket still sported its original Monoblocs and they were in decent shape. The slide stop screws had been tightened a bit to much which put a crimp in the slides causing them to bind. Once the slides were out examination of the bodies showed they were in serviceable condition although new slides are required. Some of the fittings were rusted or had pliers put on them at some point in their life which grooved them up. One of the jet holder covers was seriously grooved. Why??!!!???!!

A bit crusty but mostly there....the original 389 Monoblocs

The slides were slightly galled and binding.

Plier marks are normal violations on these old carbs but why the grooves????

I have had good results with my ultrasonic cleaner. This takes the bits back to their core metal in most cases. I use Simple Green in the washer to assist in cleaning and have found high heat to aid in the process. I have soda blasted carbs in the past with good results but prefer the ultrasonic cleaner now that I have the process sorted.

My secret weapon...the Harbor Freight Ultrasonic

One supplement to my process this go around was to use CLR, which is a calcium and lime removing chemical, on parts with corrosion not removed by the ultrasonic. It is aggressive and should only be applied for a couple of minutes. This final step made my carb bodies look great. I finished them with a paste wax to keep the corrosion from coming back. This is my first attempt at this process and I will have to see how it plays out over time. The initial results are very good.

Parts cleaned up....ultrasonic...CLR.....wax...good to go....

Ready for assembly.....

The bores showed minimal wear so I decided to place new slides in them which worked well on my RE build. One of the foremost experts in the field says the bodies will last for 3 sets of slides if treated properly. While I have had carb bodies bored in the past I prefer not to have the expense if necessary and I do miss the choke which you sacrifice upon a re-bore. I have heard great things about the new Amal Premiers and will try them when replacements are necessary.

The bores required a slight cleanup to get the new slides to fit. High spots were sanded with 220 grit and a brake hone was used to get a tight slip fit. The mounting flange was also dressed flat with a file to correct a past mechanics over zealous wrenching. 

I chose to use the anodized slides for this rebuild. 

They are a pit pricy but I think the additional cost will be worth it. 

Ready to go, just need to set the float height.....shim if necessary. 

Time to sort out fuel taps, lines and air cleaners.......

'64 BSA Lightning Rocket - Engine Rebuild PT II - Reconditioning

Well here I am again after an absence of a year or so. In hindsight I had a great plan.  Send the engine out for machining while assembling all of the reconditioned chassis parts. Get the engine bits back, assemble, and install it in the frame for an early spring start up - April 2022.... I was not planning on the engine machining to take a year and a half to complete, parts to be difficult to find, or shipping to be an issue. Covid delays were everywhere but we seem to be somewhat back to normal now or at least as normal as things will be. So here I am finishing the LR which may take a while as I have started other projects in the meantime. My projected startup date may have moved out but there is really not a schedule anyway....so here we go....Summer 2023?

The Lightning Rocket assembled and waiting for its "Power Egg"... 

After a thorough cleaning the Lightning Rocket's internal components were measured to factory specs to determine what was good Vs what needed an intervention. Once I had a baseline established I took my engine bits to E&V Engineering in Edmore Michigan for the machine work. Ed V is a regional expert and a great guy to work with. He performed all machine work and supplied key engine rebuild bits he did not install himself. This left me in a great starting point for engine reassembly. 

The heart of the A65, the "power egg".....tired and in need of some help, 

The cylinder was sandblasted and painted with high temperature engine paint taking care to ensure all oil passages were masked before hand. Tapered wear in the cylinders required them to be bored .020 oversize to get a square bore. The deck was milled .007 to get it flat. Hepolite pistons and rings were purchased from E&V Engineering to finish the assembly. I have had engines bored before but not decked. I am going the next level this time to get it sealed up properly. The rod big ends were bored to get them round again and small end bushings were replaced. The machining is all first rate and it's a shame no one will see any of it when it is assembled. 

The cylinder and its innards ready for another go at the road....

The crankshaft was an item that gave me a bit of a surprise. It was sent to the crank grinder to breathe new life into it and a crack was discovered via the Magnaflux process. A reground crank was found at a local source and taken to E&V for fitting and balancing. I have not had an engine balanced before and wanted to give it a try on this BSA. I have heard comments from "must do" to "not worth the money". Let's find out which it is. 

A tale of two crankshafts.

The main bearings in the '64 A65 are ball on the primary side and plain bronze on the timing side. Although the ball bearing looked good it was replaced while it was apart. The timing side bushing measured out of spec and was replaced to match the new reground crank.  The alignment of the bushing and bearing is critical so I left this to a seasoned professional. The outer cam busing was also replaced and line bored. 

Replacing the crankcase bushings is a job best left to someone with the proper tools.....

Early A65 oil pumps are made of die cast material which can wear causing a drop in pressure and wet sumping. I avoided this pontential issue with a new SRM oil pump. It will provide pressure strong enough to support an oil filter which I plan to add to this BSA. 

SRM oil pump ready to supply the rebuilt rods.

There are still a few items needed before assembling the cases. I am missing large end bearings, Hondabond 4 and early series crankshaft shims. Missing bits will be hunted down and the cases will be reunited for their installation into the frame. Let's get this thing on the road in '23!