Britbike forum Forums British Motorcycle specific Brands Triumph bulletin board thoughts on Morgo big bore kit?

Hi folks,
I'm about to do some top end work on my '64 Thunderbird and was thinking about the Morgo big bore kit as one alternative. Do the boffins out there have any thoughts about these kits?

Cas

I've done a lot of researching on these kits, and I can sum up what I have found.
I'm sure a first hand fella will help more.

The 750 kit fits right in your cases with no machining. Big plus in my book. You also have a better rod length to stroke ratio making for less wear, and tear on the engine from lateral forces. (compared to a 750 short rod engine)

Combining the kit with a 69-70 large valve 650 head will increase the flow rates, and that alone makes better power vs the small valve head on a 750 kit. You should also be able to re-use your Carbs.. Potential re-jetting may be required but that's not a deal breaker for me.

The potential down side is slightly less rpm, and more vibration IF all else remains stock other than the cylinder.
I've been told a balance ratio (on the crank) of 72% is a good compromise between what is good for the engine, and tolerable for the rider. This balance should take care of the above down side.

I'm eager to see some real world replies, as I am planning on using the same kit.

Good luck!

The boffins think the new kid should research a 1970 Triumph T120RT.

Zombie wondered where you went to...

K

Hola amigo, qué tal?

Just chillin' on the other side of the hill.

Good to see you. Why does the '70 120RT compare to his engine?
Both are Units, ans share similar cases but why that engine in particular?

LOL... I just noticed your profile. Location: in my house... Me too! :-}

East coast distributor, TriCor were modifying T120R's to 750cc using big bore kits supplied by Sammy Routt to increase capacity to 750cc to take advantage of the AMA 750cc rule

The Morgo or any other kit doesn't alter the rod to stroke ratio, but fitting a T140 top end AND rods will, which may be what you mean.

The 650 head had large valves since 64-65 and the 750s are the same size. Ports are the same size too, the twin carb ports are 1 1/8" and the single carbs are 1 1/16". I actually prefer those for most street applications.

The balance factor on the unit 650s is around 84%, the Morgo pistons are around the same weight as the Hepolite 9:1 650 pistons, and the balance factor is little affected. Well, it was so when I installed my Morgo in 79 anyway... I didn't find that the Morgo kitted engine vibrated more than a 650 at all, nor did it rev any less. In fact the opposite, throttle response was better through the range and it revved past the safe 7000rpm without hesitation.

My advice is to fit the Morgo, it doesn't wear as fast as a standard barrel either.

Good luck and have fun!

Zombie

Like others have said RT is a "Factory Big Bore Bike" About 155 done on the East Coast 45 done on the West Coast. The new kid wanted to know what the "boffins" thought about them. I thought that should answer all questions.


K

I didn't know what boffins meant so I googled it, it's not derogatory at all.
British slang from WWII referring to the scientists and engineers helping the war effort

I had to google it too. I saw it meant "better than nerds". I took that w/ a smile.

Thanks for clarifying the designation (RT) Kadutz. I learned two new words today. Maybe a word, and a half... It counts!

Dunno about boffins, but my morgo T120 doesn't vibrate more, at least as i remember. But i put it on 29 years ago.

. . . At high rpm the handlebars turn into baseball bats, though.I use narrow italian racing grips as a preemptive compensation : )

Wikipedia lists the origin of the word as a Charles Dickens character described as "very odd-looking old fellow indeed"
Enough said on that point.

The RT was developed by Rod Coates & Pat Qwens East & West Coast Service Managers. They were helping the Racing War effort.

Regarding vibration. Vibration on a TRIUMPH come on you guys need to balance your carbs, check you timing, and snug up loose Fasteners. It has been my experience that Routt kit piston assembly's weight the same as the OEM parts. I see no reason for the balance factor of a stock OR big bore kit to be different form each other assuming the same bore/overbore pistons are used.

I have read when the RT was developed the gearing was not ideal for the conversion. I will attribute that item to the Late Pat Owens

I don't know about '64 but earlier T-Birds were I believe cammed & geared differently from a T120/TR6. Just a thought.


K

I'm running a 750 kit from SRM that is ordered by Barbecue Bob Wolf in Baltimore unfinished and he has his local machinist match the pistons to the bores.

this is a current ad of his on craigslist with contact info.

Barbecue Bob

Straight-up old school with a bark much worse than his bite.

I'm running a new single AMAL with 1973 Tiger specs and the needle is in the middle notch position which made a HUGE difference compared to the top notch position. Stock points ign system , sneaking up on 500 mis and running very strong. One cool thing about this rig vice the Morgo is the appearance. Morgos stick out past the head and are very easy to spot. These SRM jugs don't. They look stock at a casual glance . Makes for more of a "cheater jug" vibe.

That's an appearance bonus, because the Morgo kit looks woeful and spoils the lines, as well as adding weight. Most other kits look standard and beautiful.

For practical purposes, there'll be no increase in power, because that's largely controlled by other things and not cylinder capacity. The power will occur at lower rpm, with higher torque. For most people, that's more appreciated.

ive used the morgo kit a few times they are good quality if they come with chrome top rings don't use them they take starship milage to bed in the pistons are from memory about 12 gramms heavier they can vibrate a bit more but you get good bolt on power for not much money and you can gear up a bit as well