Molnar Precision Ltd TGA Commando Parts

Hi Guys

After some looking at it with our website team, apparently we had a large number of attempted attacks being made from IP Addresses on Comcast networks, and so blocked their full range (if that makes more sense to anyone on here than it does to me, Bravo!)

The outcome is that we've made some changes to our system that should mean everyone has access to the website now.

If anyone has any further problems accessing the site drop me an email to sales@manx.co.uk with your ISP/IP Address and we'll get it sorted!

And as always any questions/queries/suggestions people have please get in touch! I'm going back to working on my 8 Valve Commando head (Hopefully) coming soon!

Cheers

Rich
 
I don't want to rain on your parade, however an 8 valve head for a Commando would have to be very good to be better than a normal Commando cylinder head. Many years ago Rod Tingate had an 8 valve Weslake head on his 650cc Triumph. He said he could not detect any difference when compared with a normal 650cc Triumph head. I am really impressed with the Commando cylinder head, they are much better than a Bonneville head, If someone made a Triumph head similar to a Commando head, they might make a dollar if people were still riding old 650 and 750 Triumphs. But with a Triumph head, the pushrods at the rear of the cylinder cause the inlet ports to need to be splayed. I suggest the advantage the Commando head has, is the inlet ports point directly at the exhaust ports. It might matter at TDC when both valves are open. If there is resonance across the crown of the piston - in a Triumph Bonneville head, the pulse has to turn. In a Commando head it is more direct. I suggest it is not about gas flow at low speeds. What is going on is probably rapid blasts across the crowns of the pistons. The exhaust system affects the tuning.
 
Last edited:
I have read some comments about 'reversion'. I don't understand them. With my motor, I have made sure there are no steps in the exhaust ports.
 
acotrel said:
I don't want to rain on your parade, however an 8 valve head for a Commando would have to be very good to be better than a normal Commando cylinder head. Many years ago Rod Tingate had an 8 valve Weslake head on his 650cc Triumph. He said he could not detect any difference when compared with a normal 650cc Triumph head.
Click to expand...
All my parades are in the rain.

Not only that an 8-valve head would be an expensive retrofit.

Mentioning that an 8-vavle head for a Commando might be soon, could have been a shot at humor.
 
Schwany said:
All my parades are in the rain.

Not only that an 8-valve head would be an expensive retrofit.

Mentioning that an 8-vavle head for a Commando might be soon, could have been a shot at humor.
Click to expand...
Do I detect the possibility of the worlds ONLY 8 valve P11 ??

That would be sumthin’ !
 
Fast Eddie said:
Do I detect the possibility of the worlds ONLY 8 valve P11 ??

That would be sumthin’ !
Click to expand...
Yeah, it would be different, but I think I might have to let someone else do that. I'd want to build a new engine cases up. So it would be a bit expensive. If I could figure out a way to get younger and stronger I might consider it, but so far getting younger is mostly in the head and not so much in the body.

I would like to see the design and find out how many parts need to be replaced to make an 8-valve head in an old Norton functional.
 
Schwany said:
Yeah, it would be different, but I think I might have to let someone else do that. I'd want to build a new engine cases up. So it would be a bit expensive. If I could figure out a way to get younger and stronger I might consider it, but so far getting younger is mostly in the head and not so much in the body.

I would like to see the design and find out how many parts need to be replaced to make an 8-valve head in an old Norton functional.
Click to expand...
All of them!🤣
 
Schwany said:
Yeah, it would be different, but I think I might have to let someone else do that. I'd want to build a new engine cases up. So it would be a bit expensive. If I could figure out a way to get younger and stronger I might consider it, but so far getting younger is mostly in the head and not so much in the body.

I would like to see the design and find out how many parts need to be replaced to make an 8-valve head in an old Norton functional.
Click to expand...
It’s supposed to be being designed to bolt onto a stock engine.

When we look at Rickman / Nourish heads on Triumphs, this will likely give some gains, but the big gains will come when cams, carbs, compression ratio is also optimised to suit.

You already have the big carbs and hot cam. And rods, pistons, barrel and crank. AND even the gearbox.

All you need is a set of Molnar cases and the head and you’re all set !!

I’m looking forward to the build thread already… 😁
 
Schwany said:
...................so far getting younger is mostly in the head and not so much in the body.......
Click to expand...
Indeed, but I am finding that a change of medication and a major exercise programme is making me feel as if I am a bit younger.

35km on the bicycle on the voie verte yesterday, not much time left for motorcycles!

I know 35km isn't much by many rider's standards, but it is not bad for a 70 year old returner, and the last 5km was all uphill!

And, much better than nothing!

The biggest problem with an 8 valve head is that it isn't eligible for any race class, and if by some miracle that changes, everyone needs one!
 
SteveA said:
Indeed, but I am finding that a change of medication and a major exercise programme is making me feel as if I am a bit younger.

35km on the bicycle on the voie verte yesterday, not much time left for motorcycles!

I know 35km isn't much by many rider's standards, but it is not bad for a 70 year old returner, and the last 5km was all uphill!

And, much better than nothing!

The biggest problem with an 8 valve head is that it isn't eligible for any race class, and if by some miracle that changes, everyone needs one!
Click to expand...
I feel pretty good at 73, but I remember being young. Not that guy anymore by any stretch of the imagination.

I cycle every other day for an hour on a bicycle on a trainer. 24.5 mph average currently. Would translate to slower on the street. I won't ride on the street anymore around here though. That feeling of being invincible has left the building. :)

I'll defer to the track day and wealthier men on installing an 8-valve head on an old Norton engine. As much fun as it would be doing the retrofit and saying I did it, I think it is impractical for a P11 750. Mine is already on the ragged edge of being able to stay together. One should never say never though.
 
Schwany said:
I feel pretty good at 73, but I remember being young. Not that guy anymore by any stretch of the imagination.

I cycle every other day for an hour on a bicycle on a trainer. 24.5 mph average currently. Would translate to slower on the street. I won't ride on the street anymore around here though. That feeling of being invincible has left the building. :)

I'll defer to the track day and wealthier men on installing an 8-valve head on an old Norton engine. As much fun as it would be doing the retrofit and saying I did it, I think it is impractical for a P11 750. Mine is already on the ragged edge of being able to stay together. One should never say never though.
Click to expand...
Since when has impractical been an argument ?!?
 
I'm starting to begin a rebuild of the original engine for my 750 Commando and have been looking for decent cylinders. I'm going to build it to stock specs, nothing high performance. Today I saw the Molnar post on Facebook and quickly went to the site. Of course, I'm living in the past so the price almost gave me a heart attack, but the writeup sounds pretty good. Not sure I can bring myself to drop that sort of coin on cylinders alone but...
 
Molnar Precision Ltd TGA Commando Parts

scroll up above pix 👍:cool:



www.facebook.com

Molnar Precision Ltd | Preston

Molnar Precision Ltd, Preston, Lancashire. 1,530 likes · 5 talking about this · 3 were here. The official page for Molnar Precision Ltd. Come here for updates on what we're doing, reports from the...
www.facebook.com www.facebook.com
 
I suggest that getting better performance out of a Commando engine by fitting an 8 valve cylinder head, might be wishful thinking. The valves in a 8 valve head are lighter, and that potentially raises the rev limit, however the crank and crankcases preclude that approach to gaining more power. Fitting an 8 valve Rickman head to a Triumph 650 engine never did much. A Commando cylinder head is much better than most of the heads on early British motorcycles. It would be difficult to improve. And in effect, there is probably no need. The engine itself is probably fast enough. The secret to getting more speed might be in the way it is used. I do not think many guys who race have 6 speed close ratio gearboxes and bikes which handle like Manx Nortons.
 
What Kevin Cameron says about combustion and the Commando cylinder head in this video, I totally agree with.
 
When you build a race bike, you should never expect its performance to meet your expectations. It always takes a lot of testing and modification to get it really going. Your mindset is important. If you always look for competitive advantage, you will find there are more than one ways of being faster. With a Commando engine, if you improve it, the improvement is more difficult to detect because of the heavy crank. The need to change the gearing is not obvious. You can be riding the bike and believe it is going as fast as it can, until you change the gearing. Raising the gearing should not make a bike accelerate faster. With a light crank, raising the gearing usually makes the bike accelerate slower.
 
When I first started racing my Seeley 850, I wondered what the hell I had struck. The wide ratio gearbox was useless, and the motor seemed to be revving without really pulling. The gearing it will pull is absurd.
 
Back
Top