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[aviationfred]

On the lookout for a free flowing, sprung exhaust system now.

The RPM exhaust to my knowledge is a free flow exhaust. Extremely light weight and his held together by springs.

http://rpmracingca.com/proddetail.asp?prod=RPMHeader


Fred

[Indiana jones]

On the lookout for a free flowing, sprung exhaust system now.

That’s funny!   I’d assume it would have to be custom fabricated ... stainless?  Or TITANIUM!!

A nice XJR system might need the link pipe modified a small bit at most.
For that reason, stainless would be preferred.
The engine is still the same. 

[Pat Conlon]

I enjoy Kevin Cameron’s articles:
https://www.cycleworld.com/exhaust-pipe-retaining-springs-50-ways-to-get-it-wrong
I remember breaking springs in the old days before swivel hooks.

Only Kevin could make exhaust pipe springs interesting.

Fred, does the RPM system use swivel springs?

[racerrad8]

Fred, does the RPM system use swivel springs?

Nope. The springs do have the rubber sleeve,but no swiveling ends.

So after many hundreds of thousands of miles ridden on the RPM header system I have never heard of any broken springs.

Randy - RPM

[Indiana jones]

On the lookout for a free flowing, sprung exhaust system now.

The RPM exhaust to my knowledge is a free flow exhaust. Extremely light weight and his held together by springs.

http://rpmracingca.com/proddetail.asp?prod=RPMHeader


Fred

I will have to try source something in Europe.
Shipping and tax makes everything overly expensive from North America.
My budget is screwed after buying the frame.

When it is all added up,it wouldn't have been much more expensive to buy a Harris F1 frame.
But I don't see the advantage of the old school, brass welded Harris frame ,apart from it being period correct,and more desireable.
Sure, more flexibility was required back in the 80s with the tyre and suspension tech that was available.
Also, the likes of the TT circuit was a lot bumpier back then,as were most circuits,I would imagine.

I'm looking at a set of Moto Martin headers on Fleabay with a flat 4 into 1 collector box with a 57mm outlet.
Granted a 4-2-1 set up would be better.

[Indiana jones]

Boom. Stainless,sprung Akrapovic 4-2-1.

[JMR]

 That's a good pipe.

[Pat Conlon]

I've always wondered for racing purposes....On a 4-2-1 system, if the engine firing order is 1-2-4-3, for proper merge design and scavenging shouldn't the #1 and #4 primaries be connected together and the #2 and #3 be connected?
....it would mean the #1 pipe would have an uneven length in order to cross over #2/3 to connect to #4, or vice-versa, so I suspect that it's more important to have equal length primary pipes vs merge design based of firing order.

All this stuff must have been figured out on a dyno.

[Indiana jones]

Most of the TT spec and Phillip Island bikes have a 4into 1 config, obviously the preferred set up when the budget is there. I'll have to settle for the poor mans choice.
I have located Nova close ratio gears for the standard tranny.

[Indiana jones]

Hanging up there nicely

[giantkiller]

Wow!!! Fj porn!

[Indiana jones]

An 11000 mile xjr1300 engine is now going to be the basis for my race engine build.
I'll get it in the frame,as is, while I'm getting a head done.
I can get it wired and running.

[fj1289]

Awesome progress!  Can’t wait to see/hear the finished bike used in anger!

[Pat Conlon]

I’ve been told that a lot of the race car guys sleeve the XJR cylinder blocks for durability. It seems that with the XJR’s  oem Niksil plated aluminum bore trends to oval under hard use.

What are your plans for your engine?

[Indiana jones]

I've been chatting to Roger Winfield about the best pistons, etc.
His super reliable motors run std xjr13 pistons in std bores with zero problems. Any engine failures have been attributed to pushing things a little bit too far in the revs.
I'm pretty sure he's run an engine for 2 seasons and a precautionary strip revealed minimal wear.
I'll be hoping to get around the 140hp mark with head work,full system, stage 1 Yoshi cams, Mikuni 38 flats and a Dyna ignition.
I have a beautiful lightened crank but I think this will have an adverse effect on power delivery.
I have some Nova close ratio gears to help close up the gaps between gears.
I'll be using a Barnett spring conversion till I can afford a Sigma slipper unit of work out how to convert a zx10r clutch, apparently super reliable and smooth.