Tales from the Emporium

**Padmei** · 29th August 2009, 07:53

Hey isn't that the screw from my front fairing? I wondered where it got to...

**NordieBoy** · 12th September 2009, 16:01

I just weighed my DR seats and found...
Stock - 2.1kg
Modded Corbin - 4.5kg!

I'm looking at making a core out of 5cm thick camping mattress type foam and a 3cm layer of bonded foam over the top.

My current modded seats are pure bonded foam which is quite heavy and water absorbant...

**NordieBoy** · 12th September 2009, 16:02

Also 168g of lead isn't enough to balance my nubblie rear with a cheap rimlock.
The front with a Talon rimlock balanced with 49g.

**warewolf** · 12th September 2009, 20:34

Originally Posted by NordieBoy

Also 168g of lead isn't enough to balance my nubblie rear with a cheap rimlock.

Maaaaaate this is a family site. We don't want to hear about your rear, nubblie or otherwise!

**pete376403** · 14th September 2009, 19:18

Originally Posted by NordieBoy

Also 168g of lead isn't enough to balance my nubblie rear with a cheap rimlock.
The front with a Talon rimlock balanced with 49g.

Shouldn't you put in two rimlocks, opposite each other? Then all you'd have to balance is the tyre, not the tyre AND the rimlock.

**MXNUT** · 14th September 2009, 19:35

Originally Posted by pete376403

Shouldn't you put in two rimlocks, opposite each other? Then all you'd have to balance is the tyre, not the tyre AND the rimlock.

Its what i have done, it also helps if you get a flat tyre and cant fix it ( for what ever reason ) you can ride on the tyre without it coming off the rim

**NordieBoy** · 14th September 2009, 20:26

Originally Posted by pete376403

Shouldn't you put in two rimlocks, opposite each other? Then all you'd have to balance is the tyre, not the tyre AND the rimlock.

You ever changed a tyre with 2 rimlocks?

It'd take me all week.

I'm happy with 1 rimlock and a rimlock worth of lead on the other side...

**NordieBoy** · 14th September 2009, 20:31

Originally Posted by MXNUT

Its what i have done, it also helps if you get a flat tyre and cant fix it ( for what ever reason ) you can ride on the tyre without it coming off the rim

The XR has 2 rimlocks on the rear but I don't go below 18psi on the DR so even 1 is overkill.

I will be replacing the cheapie rear rimlock with a Talon sometime.

**NordieBoy** · 19th September 2009, 11:17

mx_rob has just done a dyno run comparing a stock engine with one with the high-comp piston and webcam 223 cam. Both with FCR39 carb and GSXR pipe.

39 FCR w/stock engine 39.7 hp @ 6,100 rpm
39 FCR w/modded engine 46.1 hp @ 6,400 rpm
39 FCR w/stock engine 36.6 ft lb trq @ 4,750 rpm
39 FCR w/modded engine 40.4 ft lb trq @ 5,400 rpm

It's making 40hp at 5,200rpm.
The same torque at 3,500rpm at the stock engine at 4,500rpm.

This is just dropping in the high-comp piston (from 9.5:1 10.5:1 - $190us) and the cam ($197us).

**warewolf** · 19th September 2009, 23:49

Compression always benefits low- and mid-range torque more than top-end hp. It's great for acceleration in the lower ranges. Rather than buy the piston, you could plane the head.

10.5 CR is still pretty conservative. The 640 runs 11.5.

The Triumph had 10.6 as OEM, we planed the head then fitted the 12:1 hi-comp pistons giving a mathematical CR of > 13.9:1. Fortunately in practice the wild cams bring that number down to a level it can run on pump gas with.

**JATZ** · 20th September 2009, 07:22

Originally Posted by warewolf

The Triumph had 10.6 as OEM, we planed the head then fitted the 12:1 hi-comp pistons giving a mathematical CR of > 13.9:1. Fortunately in practice the wild cams bring that number down to a level it can run on pump gas with.

The more I find out about that Triumph, the more I like it

Discovered yesterday, it''s very stable at twice the open road speed limit

**NordieBoy** · 20th September 2009, 08:07

The piston is also lighter and is a "drop in" replacement.
The kit also comes with the metal base gasket I'm missing at the moment.

When I do the base gasket I'll bolt on my worked head and there's a bit of oil bypass from cold from either valves or rings wich will be gunging up the piston a bit so replacing the piston should be easier than cleaning it...

**Woodman** · 20th September 2009, 08:40

Originally Posted by warewolf

Compression always benefits low- and mid-range torque more than top-end hp. It's great for acceleration in the lower ranges. Rather than buy the piston, you could plane the head.

10.5 CR is still pretty conservative. The 640 runs 11.5.

The Triumph had 10.6 as OEM, we planed the head then fitted the 12:1 hi-comp pistons giving a mathematical CR of > 13.9:1. Fortunately in practice the wild cams bring that number down to a level it can run on pump gas with.

Must be careful when planing an ohc head as it will effect your cam timing as the chain tensioner comes into play.

**warewolf** · 20th September 2009, 17:32

Originally Posted by Woodman

Must be careful when planing an ohc head as it will effect your cam timing as the chain tensioner comes into play.

Yes, it's pretty marginal but slightly retards the cam timing which can beneficial to the mods anyway.

Planed with std pistons not much issue with clearance to the valves, but when they fitted the hi-comp pistons as well they were very careful to check clearances.