Just a small preview I've what I've been doing for the last few months. I was just going to fit a new set of ported heads that were done by WFOLarry in the States, along with new Cams to wake up my already pretty strong 95 that I'd built a while back. It had Hallam ported heads, 10.25 cast SE pistons, Andrews TW31 Cams and a Mikuni 42mm Carb. I then went down the path of building a stroker, and looked at all the options including 117/120/124 etc. I decided on using a set of new SE cases that are already machined to fit the 113/120 4.060 cylinders. I then had Darkhorse (Hoban Brothers) build me a stout bottom end using S&S 4.375 flywheels, and had them lighten and true/weld/balance the crank to suit the Headquarters 4.060 +.05" -7 cc dish pistons.
TBC
oooooh yeah now we are talking
this board needs more like you Speedster. good thread, what carb will you use? i like the 113 inch
John at Darkhorse is great to deal with. After they built the Crank, I decided to get them to do the tapered Timkem conversion to the SE Crankcases, and I also had them fit the crank and set it up. I figure as they are arguably the best around at what they do, it made sense !
He didn't push the Timken, but I wouldn't be happy if I didn't get it converted. I'll try and explain why I went 113 instead of going bigger, knowing that it wouldn't cost a lot more to go up to a 124. I have tried to research as much as possible, and came accross people that had issues with boring cases/cyinders to suit the 117 etc'. Also, I've heard of lots of cylinder problems, and I don't like the idea of plated cylinders that some use, and I don't want any base gasket leaks. So I went with HD SE 4.060 Cylinders, bored .05" to suit the HQ/CP pistons Another reason is the 113 piston still has decent skirt length. My idea was to build a motor that will rev quickly, and is really happy at high revs, and I think the lightened 4.375 stroke is ideal. Heat is another issue that I think the longer stroke may struggle more with.
You just don't realize how many parts you need to build a complete engine from scratch !! Just a small sample of parts :
I love this stuff good one speedster
Another reason for going down the 113 path, I already had the ported heads sitting on the shelf from my previous plans. They were set up to suit my 95" that I have mentioned, and as such, they are classed as stage 2+ heads, with 1.90 inlet and 1.625 exhaust Valves. In between all this, I hit a Kangaroo on the bike, which put a hold on my 95" upgrade plans. Now I really should be running closer to 2.0" inlets, and a larger inlet manifold, but they are what they are ! The heads might have struggled to get the best out of a bigger displacement motor. They are set up with beehive Valve springs that are rated to .650 lift, as my plans were to run Tman TR625 Cams. Things got a bit screwed up as Tman had told me he could not supply these Cams in the conversion style that I needed.
I already had all the later hydraulic Cam plate parts sitting here, and didn't want to use gear drive Cams. A little more thought, and after using Woods TW7 Cams that I used in my brothers bike, I chose Woods TW8 cams. They probably would be happier with a little more compression than I have, with the 47 degrees inlet close, but should make for a nice streetable engine, that starts well, and will handle any fuel at a pinch. A few figures for those who care, with the combo' of 84cc head chambers, -7cc dish pistons, piston deck height of -.002" and a .030" head gasket, I should have a static compression a bit under 10.5:1, and with the 47deg inlet close, the corrected cranking should be around 195psi .
Someone mentioned having the motor in the Laundry ! Well, it's winter in Victoria, so it was either the Laundry or the Living room !!
Cam plate and TW8 Cams:
Oil pump in place:
Cam plate/Cams fitted:
I have fitted a Barnett extra plate Carbon kit to the stock basket, along with the SE spring.
If there is a problem, I will fit an AIM VP92 later.
