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Visionary
Posts: 2300
Georgia, west of Atlanta | I saw a picture of the new indian heads off the bike and inverted so you could see the combustion chamber and the valve faces. Three things struck me 1) the Intake valve is big ( over 2 inches ) and there is plenty of room between the valves for larger valves still. 2) The valve angles are almost vertical to the cylinder bore Not like the valve angles on a Harley TC or Evo head, This is a " back to the future" modern design. Far from the detonation problems of Hemi headed air cooled engines. 3) The heads are massively finned, the pushrod tubes go through very wide finning like a Harley XR-750 race bike. That's very good. Street Harleys never have enough finning to shed all the heat they produce.
Lastly the hot rodder in me immediately thought Hmmm, Exhaust on the right side, intake on the left. Man you could use two front heads and have dual straight port intakes on the left side of the engine like a Vincent except with more modern combustion chambers. Hmmm in a small frame bike ( Scout ?? ) you would have a massive engine that would be capable of 1.3 times the Horsepower of any similarly hopped up center V fed engine........And look bad to the bone. Maybe Landspeed racer stuff.........Take back pushrod records from Harley at Bonneville.
Would Indian / polaris ever do this ?? Probably no, too much cost for a product that would be very specialized. Then I thought to my self "Polaris already makes dual port heads", AND they are 100% downdraft with no turns leading to the valve faces And they have two intake valves. yep they are on every Victory engine made..... |
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Visionary
Posts: 2300
Georgia, west of Atlanta | And yes I know, I go overboard sometimes............ |
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Cruiser
Posts: 226
on the edge of Los Angeles | If your thinking this way others are too. Will someone do something with one of these two designs and come up with their own configuration time will tell.
To me the driving force is what one can do within the competition rules within a racing sanctioning body.
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I recall in the early Pro Stock days of drag racing I think it was Gapp and Roush" that worked with pairing port designs and combustion chambers to develop performance based designs.
So who's gonna be the first to build an engine with 16 to 1 compression and 1 inch lift? |
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Visionary
Posts: 2300
Georgia, west of Atlanta | Home work on that's done I think, NHRA Pro stock Buells and V-rods are there, now that the V-rods were forced to go back to push rod engines. Last year's DOHC 160 inch V-rods were deemed to have an unfair advantage........Maybe they did, they were setting records almost every other race. |
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Visionary
Posts: 2300
Georgia, west of Atlanta | I'll predict this, the two valve heads of the new Indian engine will not produce the flat long torque curves we are accustomed to with VV engines. Three reasons 1) two valve heads cannot fill the cylinder equally over the entire rev range. 2) This engine is fairly long stroke 4.45 inches with a by these days common just under 4 inch bore, it will fill the cylinder early and then start to drop off probably around 4500rpm, kinda like a Harley. The often mentioned 119 ftlbs of tq @ 3000 rpm kinda shows that. 3) With one throttle body feeding both heads you have the back and forth air pattern that all narrow angle V-twins with one intake manifold have to deal with. It will not be as easy to hot rod these engines as it is with the Freedom 106. |
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Iron Butt
Posts: 1066
Peru, IN | You lost me after "I saw a picture of the new indian heads off the bike...". Best of luck with whatever it is you're trying to do. |
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Visionary
Posts: 2300
Georgia, west of Atlanta | I do get carried away sometimes, sorry about that .............. |
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Cruiser
Posts: 111
| As you pointed out, using two front heads allows a split intake manifold. While it's true four valves are better than two, NASCAR does alright. Someone will do an aftermarket head that will help. The Yamaha Roadstars use push rods with 4 valve heads. |
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Visionary
Posts: 2300
Georgia, west of Atlanta | Yes, two valve heads do have some problems compared to four valve heads, however like you said they can be made to flow very good. All the "traditional" hot rodding techniques for these have already been worked out during 40 years of Harley hot rodding. The two front head solution I mentioned before is an extreme answer to this, really just for race bikes or max effort street riders. here's an example on a S&S prepped land speed Harley shovelhead........Of course the Indian heads would have the induction on the left side.
Edited by XRsteve 2013-08-12 5:37 PM
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Cruiser
Posts: 111
| Using two front heads would probably be the cheapest way to set a LSR and the coolest way to be in the push rod class.The left side entry would most likely be a cleaner shot to the combustion chamber and clean up the exhaust/intake being on the same side. Be nice to have a data logger to help with fuel maps. |
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Visionary
Posts: 2300
Georgia, west of Atlanta | rebelce - 2013-08-12 6:48 PM
Using two front heads would probably be the cheapest way to set a LSR and the coolest way to be in the push rod class.The left side entry would most likely be a cleaner shot to the combustion chamber and clean up the exhaust/intake being on the same side. Be nice to have a data logger to help with fuel maps.
Yep, would be quite an endeavor but mucho cool. I bet there are some "old" Indian dudes who have been waiting to take back records from Harley for years........ And yes Fuel injection and data logging would be way better than two giant carburetors......... |
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New user
Posts: 2
| Sorry to be contributing to non-Vic chatter here. FWIW, the issue with moving around the heads - be it two front or two rear - on the 111 is the pushrod tube angles and the 3-cam design. Having not had my fingers into one, this may not be much of an issue beyond having a custom center and rear cam ground. |
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Visionary
Posts: 2300
Georgia, west of Atlanta | My thinking is the heads have to be mirror symetrical because the front and rear intake are both on point for the dual lobe center cam. I'm sure the distance laterally between the intake rockers and exhaust rockers are the same on both heads if so, two front heads would be a fairly easy trick for max effort hotrodders............I know this from using two front heads on a Sportster project to make a Substitute XR style XL........ |
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New user
Posts: 2
| This is true. |
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Visionary
Posts: 2300
Georgia, west of Atlanta | Ilikebikes - 2013-08-19 10:05 PM
This is true.
Thank you, someone that undestands what I'm saying......... |
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Cruiser
Posts: 111
| XRsteve, are you churning ideas to go for a record? If so please keep us all in the loop. Back in 2000 my friend and I sat a XO/VGC record in a '41 Chevy with 3 S&S model B carbs. As you probably know, it's a blast on the salt.
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Visionary
Posts: 3773
Pittsburgh, PA | there used to be a video on youtube where victory explained the differences & Advantages of Our design (heads and valves) over yamaha & HD. They spoke about why they choose what they did... I just cant find that video to save my life... |
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Visionary
Posts: 2300
Georgia, west of Atlanta | Arkainzeye - 2013-08-20 9:06 AM
there used to be a video on youtube where victory explained the differences & Advantages of Our design (heads and valves) over yamaha & HD. They spoke about why they choose what they did... I just cant find that video to save my life...
Many reasons: 1) SOHC engines have no pushrods to flex and the valve train is lighter and less complicated. Both the HD and Yamaha are pushrod engines
2) Four valve heads are superior in a few ways: The valves are smaller and lighter but the combined valve faces are larger in sq inches. The springs are smaller and lighter so less spring tension is easier on rocker arms. 4 valve heads flow more air with small cams, again easier on valve train.
3) One draw back: at immediate throttle opening at low rpm a 2 valve head will flow better for maybe a second or two. Then the four valve will surpass it and stay ahead in total flow. That is one reason the new Indian engine feels so strong down low. That plus a 4.45 inch stroke with appropriate cam really sucks in the air at low rpm.
I'm only talking stock castings. Of course there are head porters that can make up for the these weaknesses and make both a 2 and 4 valve head work better........... |
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New Indian heads:
