Rollingalong

Did you know you can get the hi compression JE std bore pistons in the Super Hawk motors without splitting the cases's ? Of course the heads have to be removed but your almost there when adjusting the valves .

Just take the oil pan off and there you'll see the rod bolts .

Now one of them on the front cylinder is tough to get to but it can be done . Also , stick an oil soaked rag down in the bore when honing .

The JE's stick down in the bore a bit . Thats called negative deck height . The best way to correct the quench is to remove and disassemble the motor and measure how far down the JE piston sets in "your" motor after mocking it up without the rings installed because all engines will have different tolerances . I cannot say the .030 I removed from mine will be the amount you need to remove from your deck .

I leave some safety margin . Some builders will let the piston ever so gently kiss the cylinder head . I take the compressed thickness off the head gasket into consideration along with how far the piston sets in the bore and go for .025 or so total deck clearance if a good connecting rod is being used . The VTR1000F rods are fairly good ones IMO . Guys that break those need to relearn the basic fundementals of gear shifting again

Anyway , and engine with the deck height set will be less prone to detonation ,run cooler and make more power and potentialy can use less octane all else being equal over just sticking aftermarket pistons in .

This is not a must with the JE's , just additional attention to detail while the motors apart . Ever wonder why some bult motors run better than the next one with near identical parts ?

BTW , decking the block will probably lead to the need to re-degree the cams also because they will wind up retarded in relation to where they started which is 102 intake - 107 lca exhaust stock .

The stock exhaust cam is fairly hot at 254 degree's of duration @ .040 lift and .405 lobe lift . It's the intake cam that weak in the knee's ... 250 duration@.040 lift and .400 on the lobe . The stock retainer to guide clearance is .435 . A motor needs .030 extra clearance for safety .

If you want to get a low cost boost just send your intake cams only to Webcam and tell them to try and maintain the stock base circle and ask for grind #814 . It's 259 degree's of duration and .402 lift and can be used with the stock valve springs which is a plus for those not needing a valve job or wanting to put the motor on full tilt .

The way Webcam indexes off the stock Honda cam does not change the LCA much if any and a plus is that the intake is advanced vs the exhaust cam anyway so just bolting it back in w/o degreeing is possible even if it's off 1 degree advanced or retarded in relation to the crankshaft.... 101 or 103 vs stock 102 + no big deal especially if you don't own a cam degreeing kit . They charge $250 bucks for the two Intake Cams . Now if your cams are in poor shape where they run on the head's plain bearings maybe you want to think about the Moriwaki Stage 1's for 599.00 intake and exhaust which allows use of the stock valve springs and are a bolt in cam not requiring degreeing them in . Key word there...require Or just simply sending in all your cams for grinding

The stage 1 Morwaki Cam specs
255 duration @ .040 lift .405 lobe intake
249 duration @ .040 lift . .397 lobe exhaust

105.5 intake lobe center angle
108.5 exhaust lobe center angle

Same valve clearance cold as stock when adjusting during initial install or routine maintanence

Oh yeah , port work , port work , port work if at all possible . It helps tremendously .

Any questions just ask . I've been meaning to post when I had time . Today was the day. 125- 130hp to the rear wheel is nothing to sneeze at especially the way these engines lay the power to the ground and these mods really don't add up to that much money and the only gaskets really needed is the head gaskets , cam chain tensioner gaskets and a tube of Yamabond for the oil pan .

vtrstunta

rolling, would you recommend je pistons? or moriwaki? and where did you get all your stuff from> (i mean your moriwaki cams, whichever pistons you recommend, and the moriwaki carbs?)

shayne

Rolling,

In your development have you found any benefit in air box or header size/design?
Its a known no-no to remove the airbox lid, but what about taking the snorkel out, or drilling some extra holes or a ram air set up?

My compression is 10:1 and I run standard cams, so my air requirements will be less than yours of course, but there seems to be not a lot said about these things.

Your thoughts would be appreciated.

Thanks,
Shayne

Gerrit

Site about the airbox mod:
VTR1000F Air Box Mod

shayne

Thanks Gerrit.

I have seen this once before, and would not consider doing this anyway, as I think it would be even worse on the road than on a dyno. I also think that with his engine spec being stock his intake runners were too short. Short ones are designed to work at high RPM. For his engine specs he would be better off with longer ones I think.

Unless anyone has made some different mods to this one I may have to do some experimenting.

Cheers,
Shayne.

VTaRse

Just starting a JE's, gasflowed heads and cam grind rebuild.

Started today, in fact, and re-read your useful post.
But one thing occurred to me- you say that the intake cam is the weak one, and that holds the motor back.

But the cams are interchangeable, so why not just fit two sets of exhaust cams?

Sure, they'll need degreeing in, but it's gotta be an improvement over stock?

Any thoughts, or better yet, has anyone tried it?

lazn

https://www.superhawkforum.com/forum...ead.php?t=9063

mboe794

I've been toying with the idea of simply switching the intake and exhaust cams with each other. They would then very closely match Mori's specs, with degreeing of course.

I came across a thread on this topic once a while back but I don't think anyone actually did it. I may be the first to do it this winter.

HRCA#1

Did you ever do it and more importantly did it work!? Actually in looking at your mod list it seems you did do it and it did work..think I'll give it a try.

zmaniv

HRCA any updates?

HRCA#1

Sadly no..just paid my taxes so no money left for a couple of months. Besides I'm still dealing with all the stuff I bought from Inderocker. Also waiting on my Kreigers (shipped today). I found a set of exhaust cams of fleabay for 90 bucks but think I missed them.

Also trying to decide what direction I want to go with my bike, I don't really dig the streetfighter look, but I may do a cafe racer (old school) but need to put more thought into it. Might be cheaper than a complete restoration to showroom condition.

masterhacker1989

What No pics?

mboe794

After measuring everything myself it turns out there isn't really a way to get terribly close to any aftermarket cams. There is some false information floating around the web that would make one think otherwise. The only thing I found is that the exhaust cam has slightly higher lift than the intake. So I used two of those per head. Same duration between the 2 IIRC.... I don't have my notes handy currently. Then degreed them for slightly more overlap. Playing with the timing is probably gonna be more beneficial than the actual cam swapping if you're looking to change engine characteristics.

Everything seems to be working as I would expect though. Haven't had the chance to get it back on a dyno lately. I guess I didn't have huge expectations for this mod, mainly just trying different things to see what happens. It is a currently a track bike (not racing) and running about how I want it to out there, so I haven't been terribly concerned with the dyno numbers. Maybe soon though.

zmaniv

Another question on this old thread.
Installing JE pistons into another motor. Where do I measure the squish band at?
The two large lands between the intake and exhaust valves respectively?

HRCA#1

Another question on the JE installation. Did you deck the block or the heads. In the old days we'd simply take a millimeter (.040) off the head and sometimes off the base of the cylinder block (I4) wherever we could do it and not get caught. Course that was the seventies before you could get "stock" pistons from the factory that did all that for you.

jscobey

i know this is an almost 10 year old post, but im going ahead with this method on installing my JE pistons. after talking to a number of people, it really is the choice that makes sense. financially and from a technical aspect. after all im not building a race motor. as long as when i open things up and measure the bores and things are within spec, it should be good.

im trying to keep things really simple in doing this. heres how it will go, at least in my head....

1. get rear cylinder to TDC and remove the rear tensioner & cam shafts, then the rear head itself.
2.remove oil pan and remove rod bolts for rear cylinder.
3. pull rear piston, light hone, wash, replace piston with new rings, pins, and clips.
4. torque up new con rod bolts.
5. replace head and cams will go back correctly at TDC via marks on cam sprockets.

then repeat steps for front cylinder.

im trying to leave little margin for error. im going to be doing one cylinder at a time start to finish, to avoid any timing issues from pulling both heads off. i figure if i do one head at a time, i can just keep the cylinder on TDC and know exactley where to replace the cams.


ive still yet to find out weather its needed to remove the clutch and oil pump in order to get to the con rod bolts. ive seen a number of photos where they are doing the pistons with the clutch cover on which leads me to beleive that its possible to get to the con rod bolts without the headache of removing the clutch and oil pump. either way if i have to remove the clutch and oil pump then so be it. just trying to keep things simple and isolate a problem should something arise.

NZSpokes

Pics when you do it please. And where did you get your pistons? Are they lighter than stock?

jscobey

ahhh thats one of my flaws when it comes to working on the bike. i always plan on taking lots of pictures but i get so in the zone that i forget which is a shame. im always really glad when the guys on here take the time to photo-document the work they are doing so you not only have a right up but i visual reference too. it really helps with understanding the process of the job.

i got the pistons on Ebay from a seller named Niche Cycle i believe. they were brand new and came with the pins and circlips. they dont come with the piston rings so youll have to get those when you buy your gaskets. i go them from fleabay because they were $100 cheaper than of JE's website.

and yes i know they are lighter than stock. each piston weighs about 385 grams. im not sure what stock pistons weigh, maybe Miky will chime in here, but i know they are lighter than stock.

RCVTR

I remember this guy selling engine parts after taking .030 off the block. I assume he crashed pistons into the heads.

Don't listen to what he said. Replacing pistons and rings requires cylinder and deck preparation. If you don't want abrasives and dirt inside your engine, do it the right way.

jscobey

well im deffinatley not gonna be decking the heads or block. and its a method thats been used by many others with fine results. plus i did research on "rollingalong" and havnt found one shred of evidence to a blown engine. looks more like he bought a newer bike and sold all the goodies on his VTR.

pistons get done in similar ways all the time when you dont wanna shell out the cash for a full strip and rebuild. its pretty close to how ive always done my dirtbikes. im not building a race engine with less than 2% leakdown. and compression test yeilded near perfect results. ill measure the bores and if things are way out then ill have things bored and resleeved.

the benefit is im not disturbing any bearings or internal seals so i can leave well enough alone.

RCVTR

He never said anything about a blown engine. He just posted some parts for sale and stopped talking, as I recall.

Anyway, I know you're not decking yours. You'll probably be fine. You can just deglaze the cylinders with 800 grit and WD40. Do the same thing with a very flat block to the block and head decks. Clean the bores very well with fresh solvent, until a clean rage shows no residue, then coat the cylinders lightly with oil. Be sure to lube the ring lands on the piston and a light coat on the skirts.

The cylinders will most likely be slightly out of round at the top, due to the unsupported cylinders. It's just the way it is with these engines. They may be more round with the heads bolted down. I never measured with a torque plate installed.

Good luck!