Author Topic: Preparing to rebuilt 61' Super Rocket Engine  (Read 2425 times)

Offline adunham1

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Re: Preparing to rebuilt 61' Super Rocket Engine
« Reply #30 on: 06.10. 2019 04:29 »
and worst comes to worse a place that has a shop in the US and Canada if you feel the need to spend 50% more and wait an extra month.

And which one is that?! Just kidding. That's usually how I feel when I order just about anything. Why does it have to be SO expensive?!

muskrat, that sounds like it would be a real challenge for anyone without some... let's say, insider knowledge!

I'll check the conrods tomorrow versus the old ones and see how they compare. Really hoping they're the same, but I don't believe any work has been done on the head so a few checks should tell the story. I do have the 357 cam.

coater, I bought some what I thought were new crank bolts from Draganfly and they arrived pretty rusty. It looks mostly like surface rust, but it turned me off a bit. I have bought plenty of other parts from them and been satisfied; no engine parts though. I think I've only bought a couple of bits from Fekked; maybe a cable and some crank shims.

I'll be fine on the rebuild. My Dad and I have been rebuilding bikes for the last 13 years or so. Many japanese bikes, several BSA's, and the Moto Guzzi shown earlier here. As I'm sure you, and everyone else know, it's all the little things that matter and I'm learning all the time about how to do things properly. I've got a slightly beat up set of the valanced fenders to put on the bike eventually, but that can wait until its had its break in miles completed, etc. And yes, the pistons into the barrels before the rods is much easier... unless you're the one holding the cylinders up! A wood block can solve that, though.

Offline adunham1

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Re: Preparing to rebuilt 61' Super Rocket Engine
« Reply #31 on: 06.10. 2019 04:33 »
Unrelated to the title of this post, but we managed to get some work done on the BSA this afternoon.

I bought the front end upgrade from Paul Goff with progressive springs, new upper/lower bushes, new fork seals, and the Eddie Dow type damping rods. I had those parts laying on the bike lift for a couple of weeks and thought, "I could probably knock that job out in a day" so decided to give it a shot.

It took a few hours, but we managed the job (mostly.) I'm having some issues where the RH fork leg is slightly higher than the LH side, causing the axle to not go in. Not sure what has happened yet.



Here are the old caps.

And the new ones.



Offline adunham1

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Re: Preparing to rebuilt 61' Super Rocket Engine
« Reply #32 on: 12.10. 2019 04:20 »
A little more information for anyone thinking about the GPM (Gandini) branded pistons. These are all +.040"

- Each piston weighed 281.5 grams WITH the rings installed
- Gudgeon pins weigh 67 grams
- Clips (2) weigh less than 1 gram.

For a total of approximately 349-350 grams per side.

Online KiwiGF

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Re: Preparing to rebuilt 61' Super Rocket Engine
« Reply #33 on: 12.10. 2019 11:22 »
A little more information for anyone thinking about the GPM (Gandini) branded pistons. These are all +.040"

- Each piston weighed 281.5 grams WITH the rings installed
- Gudgeon pins weigh 67 grams
- Clips (2) weigh less than 1 gram.

For a total of approximately 349-350 grams per side.

Thanks, all info like this is good, regarding a comment you made earlier, if the steel rods are “thinner” than the OEM (and they look like they are) then no mod to the barrel slots should be necessary, the extra length (if they are longer) should not make a significant difference to the clearance between rod and barrel.

The gudgeon pins are quite light compared to those I weighed, and will help offset any extra piston weight.
New Zealand

1956 A10 Golden Flash  (1st finished project)
1949 B31 rigid “400cc”  (2nd finished project)
1968 B44 Victor Special (3rd finished project)
2001 GL1800 Goldwing, well, the wife likes it
2009 KTM 990 Adventure, cos it’s 100% nuts