Dick Mann DR 370 frame

[LWC82PE]

has anyone got a photo of the DMS framed DR/SP370? i want to see what they look like

[ola_martin]

Just to blow some life into this one again, has anyone found anything?
Hallman:

[ola_martin]

Hagon: 1 pcs. produced...

[ola_martin]

Curtis: 1 pcs. produced...

[ola_martin]

Me checking out the holy grail....

[ola_martin]

or would you be better off trying to get a XL 350 framed one and mod the pick up points ?

Anyone done this?
How far apart are they in size?

[cloggy]

 I've been watching for several years but a Mann suzy has never turned up, nor has a Hallman. I've got a mark4 TT Mann frame, which are not supposed to exist.... It's so easy to ride, an apparent characteristic of Mann frames
I would imagine the suzy will be like the mark one or mark two TT frame.
The DR400 had two articles in Dirt Bike. In the second they tuned it and shoved on 38s etc
 The later 400 engines had stronger cases and even the early 400  was beefier than the 370, who's gearbox proved weak when tuned. Vic Eastwood is on record saying that a stroked DR370/SP knocked spots of his TT for power, both in Hagon frames, but had gearbox woes. It seems that in those days Britain didn't have much to do with the rest of the tuning world... There is still a Hagon 370, being refurbished at present.
Oh and the suzy is a very tall motor, despite being well oversquare. You can shoehorn just about all Honda twinshock singles into the KLX frame, but there wouldn't be much left of the kawa frame if you tried with the DR

[Tony T]

I've had my eye out for nearly 5 years now and have yet to find anything.
But being that only 25 were made, I'm not really surprised. 

[GMC]

Just to blow some life into this one again, has anyone found anything?
Hallman:

My Hallman replica is nearly there.
Jigs finished, just have to finish off some other small jobs and then I should be set to put a frame together next week.

Jigged from an original Hallman frame for the DR 400.
It will be a carbon copy except for the footpeg mounts.
The Hallman frames have those spline type mounts but I will be fitting something more user friendly like the Yamaha style pegs mounts from the NVT frames.

[oldfart]

GMC, the frame in your jig is it the one you were carring around CD 5
looks familar

[ola_martin]

Great, keep us posted GMC

That first photo is from a MotocrossAction test I guess, anyone got it??

Cloggy, thanks for the info regarding swaping a XL and DR engine. But the height difference, is it from bottom to chainsprocket, or from sprocket and up?
Oldfart kindly measured up his engine for me, http://ozvmx.com/community/index.php?topic=25939.0  and roughly it was about the same length, and about 15mm taller than my XL sideport? If that's mostly from sprocket and up, it just needs some gastankmodifications??
If anyone has some more on this, please share...

[Tony T]

Hey GMC, won't all that RHS make it a bit heavy!
I'm so funny........... 

Do I get one for free for my technical influence in the design process? 

Mr. ola_martin, I've got that test in my stash. send me a pm with your email address and I'll send a scan to you.

[firko]

Hey Geoff....you missed the golden opportunity for unlimited riches by not buying this genuine Sprite frame jig. For 150 pounds you could have been all set up to make Sprite/American Eagle frames for the ravenous masses craving for such a thing.
                                                                 

[flower pot racing]

I have a friend selling a DMS TT500.  Close but no cigar.....it's a lovely looking bike. 

Another mate is selling a Cheney Yamaha that is all ready to go.

Why a Suzuki?  The dont make much power (I am told) and you are starting with less ccs as well so to get the power up to compare with a std 500 lump you will have to do work (spend money) 

Why not start with a bigger xt/tt/xr/xl motor?

[cloggy]

 I just measured one of my DR engines top to bottom and forward to rear and there was no way it was going to fit an unbutchered KLX frame.
 As for the engines there's a guy racing a stroked version on tarmac
 Here's a  part transcript  with just the engine stuff
"Crankshaft has been stroked from 65mm to 80mm which gives 487cc
capacity (88 x 80mm). Crank has been radically lightened and
balanced to run smooth at 5000rpm plus. Con-rod is stock Suzuki
polished and then shot peened (Beiby layered) to remove surface
stresses.

Later (post 1980) SPs and GNs had much sturdier/thicker crankcase
castings and can handle some extra ooomph being put through them.
Older SPs (370 & 400s) crankcases were thinner and I blew (burst) a
few motors racing, these cases were particularly weak around the main
bearing housings and gearbox output shaft bearing holder - still got
a metal plate in my collarbone from one of these blow ups-get offs!

Original 42mm inlet valve was a bit on the small side even for a 400
so inlet and exhaust have been replace along with bigger valves (45mm
inlet), multi angle cut seats along with coil inserted and precision
reamed valve guides. Combustion chamber has also been reshaped to
minimise 'shrouding' around the larger (but lighter) inlet valve.

Inlet port has been reshaped and filled with epoxy resin to smooth
out the down curve. In fact I have made the inlet slightly smaller
in diameter (31mm) as it was too large and intake gas velocity was
low. I use a 40mm Amal MkII for long circuits and a 36mm for shorter
tracks (more torque).

Piston is stock Suzuki lightened and `slippered' with the valve
pockets ground and the inlet pocket rounded off to accept the larger
valves/increased valve lift (tuners tip #1: do not 'round of the
exhaust pocket - I have been able to pick up 0.5-1bhp on the dyno
by 'shrouding the exhaust valve with the top of the piston in this
way).

I used to use Wiseco pistons but these were heavy, expensive and I
have never had a Suzuki one break (yet). Compression is quite hefty
at 11.2:1.

Camshaft is my own grind carried out by David Newman (Orpington)
giving 0.28/29 valve ratio lift and just a little more duration.
Stock cam was pretty good and revvy for the SP/GN anyway and I lost
torque/bhp by going to a catalogue 'full race' ground cam.

Ignition is Boyer Bransden with a 12v (12N5-3B) battery total loss
system and a NGK D8EA plug - 'racing' plugs show a drop in bhp on the
dyno with unleaded fuel. Ignition pack(s) are pre-programmed and
held in a silicone vibration protected carrier.

Oil is Shell M/C mineral for running in and I use Shell fully
synthetic M/C oil for racing. Have to use 2 litres of oil instead of
the usual 1600cc as reduced crankshaft size has removed some volume
from inside the crankcases.

Exhaust is a big bore one off from Tony Cook (London), exhaust
dimensions arrived at from calculations and work carried out by Vic
Camp and Alf Hagon way back in the 1970s/80s.

Gearbox is stock Suzuki – a good strong, smooth transmission. Clutch
is stock smoothed and polished basket with moto-x grade competition
friction plates and springs for SP/DR off roaders.

Crankcase breather has been bored out and a non return valve put in
the breather `catch tank' to reduce c/case pressure and reduce
pumping losses.

52bhp @ 7250rpm at the back tyre, as opposed to the SP/DR/GN400s
slightly asthmatic 20-24 bhp, and has a quite flat torque curve from
3000-8000rpm.
In all the years I have run these bikes the only real (engineering)
problem I have had is with 3rd gear drive engagement. The gear drive
dogs have trouble handling the extra bhp/torque and after a few
hundred miles she will jump out of 3rd under power – slightly
embarrassing on track when someone is right in your 6. I have tried
building the dogs up with MIG weld and grinding them back to an
undercut profile but still the same happens so I just repair/replace
3rd gear specific engine rebuilds.
Mark
filteredsoul"