Scooterotica

Sorry to revisit old territory but would anyone like to recommend a company (preferably local) who can make porting changes to my Indian GP200 barrel. I'm looking for(hopefully) a little extra torque at all revs, a bit more smoothness from the engine. I believe that a nice tidying up of the ports would be all that's necessary but apart from smoothing out ports I am under the guidance of whoever decides to do the work. Engine is Indian GP200 gearbox and runs with 19/47 sprockets, clubman and 22mm Dellorto/26mm Jetex.Also aproximate costs.

Anyone??

rog60 wrote:Sorry to revisit old territory but would anyone like to recommend a company (preferably local) who can make porting changes to my Indian GP200 barrel. I'm looking for(hopefully) a little extra torque at all revs, a bit more smoothness from the engine. I believe that a nice tidying up of the ports would be all that's necessary but apart from smoothing out ports I am under the guidance of whoever decides to do the work. Engine is Indian GP200 gearbox and runs with 19/47 sprockets, clubman and 22mm Dellorto/26mm Jetex.Also aproximate costs.

Anyone??

If you want to get the best out of the Indian barrel..... Give it to someone to re-work the transferes in the bore to produce a better loop scavenge and more effective area, this usually gives more power... It needs the use of a 90 degree Industrial type dentist dill to access these properly...

The exhaust port dosnt need much work, widen it to 62% which it will be just about that before you start...The exhaust timing is when standard Indian, around 165 degrees... but some are nearer to 170 degrees thats as big as you will need to go... polish the port and lightly shamfer top and bottom port edges...

The barrels dont usually return much more top speed (maybe a couple of mph) with the carb reemed out to 26mm... but they seem accelerate a little better...

The Inlet area (as standard) is a little small and the port area can be increased a little and the port squared up as they are usually pretty poor to start with... I prefere to keep the port timing to no more than 155 degrees with an Inlet port height of aprox 23mm and 62% wide (again shamfer port edges top and bottom) with the 26mm reemed out Dellorto
I dont like to use the cut down Asso pistons to achive the Inlet port timings but remove cast iron to increase the port timing and area...
Port matching, inlet & exhaust to manifolds and transferes to case/mag housing... The ports need to meet inlet and exhaust manifolds, cleanly... That means no steps or lumps and humps in inlet or exhaust manifold and they should flow as one...
More width can be added to ports to increase power... but reliability is usually the main concern of a road engine...so my advice is 62% width max inlet & exhaust... This is for a standard type piston including Asso..
This is only a little of what you could do... hope it gives you some ideas... as for price, Indian barrels are very hard cast iron... and take a little more work than Italian or Spanish barrels when porting inside the transferes in the bore...
There are probably several people on this forum that could do a tune like this... Or to their own formula... I am sure...

i suppose taffspeed is the closest but IAN is due heart surgery soon so dont hold your breath
id think of sending it to harry barlow or readspeed ,chislespeed or the such like id ring various places and get a feel of the tuner and use gut instinct to choose

Or if you can wait a while Charlie will look at it I'm sure. Give him a call at Performance Tuning. There is a back log.. but well worth the wait. he'll tune the barrel to what you want, what pipe you have etc.

Mr Brady without a doubt , done mine coupled with a jl4 and tm24 mikuni = flying machine
Was a thread with photos etc of my barrel before and after, think it's on old forum?
Maybe Dan or Sean etc could rescue it and pop it on this one?

bazman wrote:Mr Brady without a doubt , done mine coupled with a jl4 and tm24 mikuni = flying machine
Was a thread with photos etc of my barrel before and after, think it's on old forum?
Maybe Dan or Sean etc could rescue it and pop it on this one?

oops never thought of him

I had a look at one at the weekend that Smiffy [R&B] on here had done, and very nice too , it ran well untill crap oil was used , changed it for one of the 225 indian alloy jobbys as he didnt want to wait to have it re-bored, it took 3 hour,s or more to tidy that up, but at least its soft alloy not cast. Contact Smiffy, to see how buisy he his.

I was looking at a couple of cast barrels I have and feeling inside the trans I could make out that one barrel had a very flat, almost 90deg entrance while the other promoted a more smoother curve (think that one is a Indian St4), briefly reading G.Bells work the steeper angle would be a better bet or did I read it wrong?

eibargum wrote:I had a look at one at the weekend that Smiffy [R&B] on here had done, and very nice too , it ran well untill crap oil was used , changed it for one of the 225 indian alloy jobbys as he didnt want to wait to have it re-bored, it took 3 hour,s or more to tidy that up, but at least its soft alloy not cast. Contact Smiffy, to see how buisy he his.

Thats intresting and thanks for comments
What was the number on the barrel

Smiffy