Head Porting

[RottenRonnie]

Has anyone looked into porting heads on the Raider???
How do they look....is there room for improvement???
With that funky pushrod angle, they are never going to rev very high; so we need to maximize what is already there...flow.

Thanks!

[Mr. T]

Don't know if this thread speaks directly to your question but it's about engine mods..
http://www.mybikeforums.com/forums/showthread.php?t=4773&highlight=Raider+engine

[RottenRonnie]

Don't know if this thread speaks directly to your question but it's about engine mods..
http://www.mybikeforums.com/forums/showthread.php?t=4773&highlight=Raider+engine

Thanks for the link! Its a start....

If changing the cam improves torque, that means the heads are already up to the task of handling more duration, lift and/or overlap from the swap.
I.O.W. the heads, must be pretty decent.
I'm not sure how aggressive the factory cam profile is...??...

Does anyone know what the stock heads flow???

Ronnie

[Curt]

porting heads?? I don't even know what that means... I do know I like the raider the way it runs now. I have stripped my raider but refuse to do any mod that compromises the integrity of the performance. I know what a Pot head is.:)

[RottenRonnie]

porting heads?? I don't even know what that means... I do know I like the raider the way it runs now. I have stripped my raider but refuse to do any mod that compromises the integrity of the performance. I know what a Pot head is.:)

http://en.wikipedia.org/wiki/Cylinder_head_porting

[snoslyd]

Ronnie, a couple of guys who may know are n2oraider and busajack. These guys are on the cutting edge. BHodge may also know.

[RottenRonnie]

Ronnie, a couple of guys who may know are n2oraider and busajack. These guys are on the cutting edge. BHodge may also know.

Thanks....I am quite new here...Are they on this Forum???

[PiNkPaNtHeR]

My two cents worth:
I haven't built any motorcycle engines from scratch, but I've built a lot of car engines - namely Fords. I've done a 289, a 302, 351C, a few 390's and a couple of 428's. My 'bible' for doing these was a book titled "Performance with Economy". OK - I'm an old fart, but I still think the same way today as I did back then. My pride and joy was my '73 Mach I with a 351C that got 318 HP at the rear wheels on the dyno and got some 22+ MPG. This is a fact Been there, done that. Please bear in mind that electronic ignition systems were fairly new at the time. I built mine using a Mallory dual-point ignition with MSD 5, Headman headers, Flex fan, Aluminum intake, 650 cfm carb (yes - I said Carburetor!), quick and simple (budget) balance and without port and polish. From my personal experience, I have hard that exhaust porting is far more important than intaking porting. In fact, intake porting can actually do more harm than good in a lot of circumstances. The friction (uneveness) of the intake can actually yield more atomization than porting and polishing on the intake side.
yup - I'm old-school, but I love the new technology. I sincerely believe that with the proper gear ratios, and a couple of minor engine mods, we can see 55+ MPG and nearly 100 HP at the rear wheel. As a side effect or consequence, that means more efficiency and more power at the same time. I know it's possible. I've done it - just not with this particular machine. It's a 'weak link' kinda thing - just like the old days. Sure you can bolt on a 800cfm carb or map your PCM to give gobs of gas at the twist of the throttle, but if you do it right, you can get more all the way around. It might take me a few years as I've just done about $7000 worth of mods in the past few months, but I'm getting 50+ MPG (unless I go nuts on the twisting of the throttle). and I can't complain about the basic engine design.
Just think of it like this:
An internal combusion engine is nothing more than a glorified air pump using liquid fuel to make it go. The smoother everything is, the better it'll perform. If you can get the right air-fuel mixture in and out smoother and easier, you're going to gain something.

My best guess, at this point, is that bigger exhaust valves will yield the best bang for the buck. A tunable fuel management system is next. AND finally, a free-flow exxhaust system (like my HK sideburner) will increase torque (and 1/4-mile times) while improving efficiency and MPG.
I'm running the stock Yamaha fuel management system and stock air filter at this point. I'm going to be doing a little research soon as to probably using a different air intake system - but am a little worried about the stock air temperature sensor. I haven't run enough miles, yet, to determine the effect of going to the Dunlop 240, but my initial results are a slight gain. Stock I was getting around 50.1 MPG. That was over 11,000 miles. Since going to the Dunlop 240, I am measuring from 47.8 to 51.3, I am guessing that this is because I am so damn happy to be riding again and have hit 100+ MPH 3-4 or maybe 5 or 6 times per tank in the past few days. My best guess, at this point, is that if I ride conservatively, I might see an average of about 52 MPG.
Keep in mind that, at the simple twist of the throttle, I can still smoke any stock HD ever made - even with 113 cubes as opposed to 88 cubes.

I will also say that the 240 feels 'right' where the stock 210 Metzler never did feel 'right'. This is just my opinion. I'm sure that other will differ.