I seized a piston a few years back and have now finally have torn down my '66 Lightning and split the cases for a refresh. I have in mind a few things that I want to do while I've got her down, but this is my first rebuild, and am looking for some advice about some of the key parts of the rebuild. FYI, I'm looking to maximize the smooth, reliable and strong-running aspects of the engine to be a daily rider -- not a hot rod. Here are my questions:
1) The head has already been gone through and refreshed by E&V. My cylinders are in good shape and measuring at just over +.02, so I will have them bored to +.04 and fit new pistons. I guess I could opt to re-sleeve back to STD, but I think there is still plenty left to work with and +.04 is not unduly pushing it on these bikes, right? I've been looking at the 9.2:1 E&V pistons, but would like to hear any opinions on other options. Also, I have read that these bikes can benefit from reduced compression -- should I consider options for 8.5:1 or lower pistons? If so, where to be find them?
2) I will obviously check my con rods, but if they are out of round, should I consider just replacing them while I'm in here? I believe they are the originals and I know there are upgrades (lighter/more durable) available . If replacement is advisable, any recommendations? Carrillo? R&R billet?
3) I think I would like to have the crank ground (as necessary) and balanced to reduce vibration/engine fatigue. I also want to get the cases line bored and a new bush installed (if necessary) to make sure my crankshaft is in proper alignment so that it can be properly set up. Am I correct that I will need to provide the barrels, cases, pistons, rings, con-rods, and crank to the shop for a dynamic balance? Is it advisable to just have all of this done in the same shop at the same time? Starting to wonder if I shouldn't just have this shop do the whole bottom end setup while its in there....I'd *like* to do the crankshaft installation/end float myself because I feel like it's the big challenge with these bikes and I really wanna know my bike, but the idea of having it done by real pros is appealing as well... Any info, advice, experiences would be appreciated here.
Drop the compression. Anything better than 7:1 will be fine. Low comp pistons are available from all the usual BSA parts sources. Having lowered the compression you should not need to alter the balance of the engine other than to correct for the weight of the new pistons. Money spent on new rods is money well spent. Clean out the sludge trap and get the crank nitrided, this will seriously toughen the crank thus reducing the chances of it cracking and if it does crack, drastically increasing the time before total failure. It is called fracture toughness. If you carbo nitride the crank, that will also make it harder which is not necessary with a BSA crank.
Plus 40 is fine with high comp pistons let alone low comp ones which will allow you go out to + 80 with safety.
No need for high comp engines any more if you are not prone to riding at double legal speeds and the way modern fuel is going, running ratios that will burn power kerro is probably a good idea.
Then all the normal things, a Tympanium / Podtronics to bring the electronics up to handleing modern traffic. A LED stop / tail will take a lot of load off the electrical system particularly if you spend a lot of time in traffic, foot on brake. An electronic ignition of your choice An external canister oil filter of your choice and you are set for another 40 years behind the bars.
Disconnect all of the bullets, polish the bullets themselves and replace the joining sleeves. The PVC tube than encloses them shrinks & hardens with age. This clamps the bullets too tight so you end up pulling the wires out when trying to disconnect them. If you have th time, a full rewire with proper fusing and relays will not hurt
Also you asked "Am I correct that I will need to provide the barrels, cases, pistons, rings, con-rods, and crank to the shop for a dynamic balance? Is it advisable to just have all of this done in the same shop at the same time? " for balancing , all in your list except the barrels and cases. However if the same shop is doing the line boring then cases ( edit here, cases AND Barrels, with the Barrels fitted the cases are held in their true position, important for a true line bore, some cases are badly doweled to the point on missalignment , mine certainly were, the barrel give a more true line up.) as well.The 71 manual states 70 percent for the static balance factor, not sure if the dry frames were the same. Con rod replacement is probably a good thing, quite spendy, my A65 still has stock rods, but these were hand selected as the best matched pair I could find in my parts stash, I found a large variation in con rods weights, getting these closely matched can only help with the balance.
For all round goodness check out the condition of the primary drive, worn chain/ sprockets / clutch adds a lot of extra noise especially once the chain wears, these tend to wear unevenly . Trevor makes good points about the stock bullet connectors, I find these to be a real PITA , I recommend Japanese style bullet connectors like these http://www.vehicle-wiring-products....erminal-kit-with-japanese-type-terminals , these are easy to use, less bulky than stock, plus the silicone clear sleeves are good at keeping water out and holding firmly but still able to disco when needed. The tool that comes with the kit is cheap and cheerful , it works surprisingly well, the lack of bulk allows easy access to tight zones.
Last edited by gavin eisler; 10/31/177:45 pm.
71 Devimead A65 750 56 Norbsa 68 Longstroke A65 Cagiva Raptor 650 MZ TS 250 The poster formerly known as Pod
Thanks Trevor, NickL and Gavin for the help! I will bore out to +.40, drop piston compression, upgrade rods, dynamically balance and machine the cases as discussed.
I did do some upgrades when I first got the bike, including: modern HL, LED RL, Sparx e-ignition, Sparx 3-phase 220watt alt/rect/reg kit, dual output 12v coil and a re-wire with solid single ground, fuses and modern (Japanese) connections. I may revisit the wiring a bit, but I think the electrical aspects of the bike are pretty solid.
I also installed a return-side external oil filter and billet sump plate with magnetic plug at that time. What are people's feelings on the SRM oil pump upgrade? I could never get a straight story about if these can be run with the return-side oil filter -- anyone do this?
As for the rest, I am already planning my attack on the sludge trap (which has been pinned by a previous visitor and is tighter than....pick your analogy). I will probably go for the allen key upgrade to the sludge door. I will also definitely replace drive side chains/sprockets and any other worn bits as a matter of course. Clutch is looking decent with beefed up MAP (or SRM --- can't recall) alloy billet pressure plate. Still 4 spring, so I think some improvement is possible there, but not sure if it's worth it...
Anyway, cheers and I'll try to post a few pics (and probably more questions) as I move forward.
Heres my take on A65 upgrades, if using the stock bush TS , then a new oil pump is a very good idea,
A65s have/ had a rep for letting go,When the TS bush wears out oil pressure is lost to the big ends, then the DS big end seizes and the rod breaks. With modern oil filters and good fitting this system can work well. As I am sure many here will testify. There is an alternative.
I run with a 71 iron pump and stock ( 1970) rods, and a big bore 732 block, but I dont care , thats the beauty of the TS end feed conversion, now the big ends get all the oil without any loss of pressure. The end feed conversion alone is about the same cost as new rods and oil pump. Ed V on your side of the pond can do it. here in the UK SRM charge about £500 for the end feed conversion, about £300 for a pump, and about £350 for new conrods, To me at least , the end feed is very good value compared to the cost of rods and a pump. Others will now chime in with how a filtered TS bush will be perfectly OK, However the end feed does a couple of things the old bush doesnt, it delivers oil to the big ends with no leakage through a bush, and the combo ball needle locates the crank so shimming is not required, Any way, I obviously drank the end feed Kool Aid years ago, it still hasnt worn off.
As for conrods fatigue life, they only age when in service ( or if the motor has seized heavily), if you think the motor has done many tens of thousands of miles then yeah, fatigue life could be an issue. If the rods are not oval or damaged/ nicked by bad handling they should be OK.
71 Devimead A65 750 56 Norbsa 68 Longstroke A65 Cagiva Raptor 650 MZ TS 250 The poster formerly known as Pod
If you're upgrading any A65 engine then its worthwhile looking at some of the changes that BSA made over the years to help improve reliability. Additionally its worth considering how many miles, how hard you ride and how much cash you want to spend.
An 1966 A65 engine will have few of the upgrades latterly introduced by BSA however many of these engines, especially the ones in a lower state of tune can run without rebuilding for many thousands of miles. There was recently a poster on this forum who claimed his A65 in original setup had covered over 150k with only 3 major rebuilds.
I have made the following mods to my 1968 A65 Firebird which I'm happy with but doesn't make them mandatory:- - Oil pump has been updated to the 1971 onward cast iron type which BSA introduced to provide better oil pressure, the SRM type pump is a good alternative and easier to find. - Conrods, I changed my rods to the later stronger types and sourced a low mileage pair, I had them inspected by my engineer before using. I don't remember which year these were introduced but may have been 1968 or 1971?. I'm sure Carillo, R&R etc. rods are great but maybe not necessary for normal road use. Maybe you could get your rods checked for ovality/stretch and replace if needed? - Pistons, I'm using generic Hepolite replica pistons which I think are approx 9.5:1 compression ratio and work fine with no pre ignition problems. The pistons sold by E&V are excellent especially as they use a modern ring pack with 3 piece oil control ring, so although I'm not using them, I would do if I was rebuilding. I have never used the low compression pistons so can't comment but personally I would use the 9.5:1 or similar pistons unless you have low octane fuel locally. - Timing side bush, I had my cases rebuilt using a new TS bush line bored together with a reground and polished crank. I felt this was an acceptable approach since my engineer knew what he was doing and I was using the later oil pump and return filter. I'm sure the SRM conversion is great although the cost/benefit analysis didnt make sense in my case. - Crankshaft installation/shimming, I left this for my engineer to sort out. You need very precise measuring equipment for this so best left to someone who has years of experience and probably best done by the same person doing the TS Bush alignment. Same goes for the sludge trap, flywheel removal/installation etc. All to easy to get wrong and cause problems down line. - OPRV, I'm using the piston type as opposed to ball type, the piston type offers better pressure control. SRM sell the piston type and you may be lucky enough to find an original BSA version. - Crank balancing, I didnt have my crank balanced when it was reground/rebuilt and the engine runs smoothly although buzzy at high RPM. I guess balancing only helps if you have made major changes to the weight of the rods & pistons. - if your bike is a Lightning then I assume its using twin carbs. It would be worthwhile making sure the carbs are in top condition.
1968 A65 Firebird 1967 B44 Shooting Star 1972 Norton Commando
David, happy to share this thread with you if you're working at the same thing. Thanks to all who have chimed in. I called Ed at E&V today and I think I have a plan -- though still on the fence about the end feed conversion vs. bush and line boring. Definitely going to get E&V +040 pistons (probably stock compression -- don't think he does low ones), MAP rods, an SRM pump and OPRV, and a grind/polish/dynamic balance for the crank. I figure that outta result in a pretty beefy build that will keep me on the road for quite some time whether i go with end feed or not. Now all I have to do is put together some cash......
Some nice tips on this thread and I'm also going through the same 66 a65 engine. I am planning to thrash the living daylights out if my mk.3 Metisse the engine sits in on the speedway track, green landing and hopefully a couple of classic off road rallies.
I had a lightning 2 carb head and have sent a thunderbolt single carb head off to SRM for new valve guides and seats and a shine.
I got a lot if good advice from SRM that I decided to strip my engine (I'm having a coffee in the garage as I type) and send the cases and crank to SRM too.
They will modify for end feed and dynamically balance with new SRM rods and new pistons and pump.
I fit a map external oil filter last year and out of everything I've done/doing to the motor this is probably the best upgrade you can do...
I'm hoping that I get a lot of miles on it in the future because it's such a fun bike.
Last edited by Manx; 11/10/173:05 pm. Reason: Can't spell