How to tell if the heads are off a 97???

[CoreyP]

A guy has a set of heads for sale that he says are from a 1997 Valkyrie. How would you tell what year they came from? The heads are interchangeable on Valkyries correct? A 1997 head would have the more horse power camshafts than a 2001 Valkyrie, correct. See where I'm going with this? Seems like a pick up some horsepower for fairly cheap.

[98valk]

From what I have found all GL1500 heads all yrs are the same.

camshafts are stamped either R1 HP or R2 emissions.  Not all '97s will have the R1 cams. most Dyno testing has shown a 10HP difference. few more better MPGs with the R1 cams also.


see cams here  https://www.valkyrieforum.com/bbs/index.php/topic,54105.0.html

[h13man]

From what I've read here, the ICU is different thus the hp. difference. Highly sought after.

[98valk]

From what I've read here, the ICU is different thus the hp. difference. Highly sought after.

Nope. only I/S ICM has faster advance to about 3k rpms, then to redline same curves.

[CoreyP]

He doesn't know but the sell er will look for R1 or R2. Doesn't look like you can see it without take the cam out of the head.

https://www.facebook.com/marketplace/item/1054516689827984/?ref=search&referral_code=null&referral_story_type=post&tracking=browse_serp%3Ab9c8f9ff-b140-4f46-93a8-5647c704c35f

[98valk]

He doesn't know but the sell er will look for R1 or R2. Doesn't look like you can see it without take the cam out of the head.

https://www.facebook.com/marketplace/item/1054516689827984/?ref=search&referral_code=null&referral_story_type=post&tracking=browse_serp%3Ab9c8f9ff-b140-4f46-93a8-5647c704c35f

cams do not need to be removed, just rotated to see. indication is near the one end

see cams here
https://www.valkyrieforum.com/bbs/index.php/topic,54105.0.html

[h13man]

From what I've read here, the ICU is different thus the hp. difference. Highly sought after.

Nope. only I/S ICM has faster advance to about 3k rpms, then to redline same curves.

Thank you for the reminder. Duh. 

97' and 99' cams are the same part number for non CA models. I see the piston is different part number from 97 thus suggesting a compression difference but...

[98valk]

From what I've read here, the ICU is different thus the hp. difference. Highly sought after.

Nope. only I/S ICM has faster advance to about 3k rpms, then to redline same curves.

Thank you for the reminder. Duh. 

97' and 99' cams are the same part number for non CA models. I see the piston is different part number from 97 thus suggesting a compression difference but...

nope on compression, per service manual all yrs all GL1500 engines have same compression, since '88.

many manufacturers change the part numbers after the 1st or 2nd yr of production of the vehicle.
HP numbers of these engines are strictly due to OEM camshafts.
The I/S slide springs will increase mpg. They lean out the needle range which is too rich. too rich lowers HP, so there is a small HP increase with the I/S springs, mostly they will provide better engine response over a wider ambient temp range.
I/S has the better fuel tank, triple clamps and rear shocks. std/tourer are better forks than the I/S.