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Aftermarket BIG Valve Cylinder Head

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BTW.... Super thin valve stems and crazy high rev limits are not my favorite combination... Bigger heavier heads and skinny stems with high rpm is not always a good idea...

But in any event...

Unless you are an expert at porting, which you clearly are not or you would have posted a thousand pics by now... You are buying lots of stuff, yet maximizing nothing ..

That's a fact...

The Spartan heads ports are junk stock

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1 hour ago, mixxer said:

Well i will readily admit that the older cr smooth bores are truly smooth and cylindrical.... they must not have been the ultimate in carb design because they did not endure to the modern age... I have heard of them but never had use for such, so no experience with them... My nomenclature was wrong with my reference to carb venturis compared to those CR's... but I still have no use for a true smoothbore after being corrected... 

Nice pictures of the bowls of the Spartan head ...lol... Why don't you post up some pics through the ports like I did... BTW, why aren't your pics as clear and we'll lit and in focus as mine?? I'm just using a cell phone to take mine...

As long as your game is to keep posting up unsupported power numbers with zero dyno graphs from a known dyno brand, on big displacement builds at supposedly 16k reliable RPM.... This will never end... Big money spent... Zero info on head work because you spend big money and bolt it together and then make up whatever power level you decide sounds great and then post it as fact....

That's an easy game to play... Check this out...

Mine makes power peak at 17.5k....

28 reliable hp and an amazing early torque peak with 18.3 tq... 

Top that with 130cc...🤘

LOLS. Down to complaining about my port photography.

As I said the Shift Up/Spartan ports are run as supplied. The critical valve seat area is as well machined as you can achieve on a Serdi machine and better than I can easily get using my cutters or pink stones. They can support about 20 hp from 145 cc so are plenty good enough out of the box

I do all my own head work but make sure I start with something I have base lined on the track, then on my flow bench.

Th ere are a couple of images. One is a head fitted with a 31 diameter  5 mm stem Ti valve and bronze seat.

It had been around and survived a couple of good blowups before I re valved and ported it. Shifts at 16000 rpm on a 49 mm stroke, 62 mm bore setup with about 10 mm of lift.

The other image shows a 4 speed.  I do 54 mm stroker with a  56 mm bore for a 134. That has a modified  CB750 carb- PC Keihin and- no photos- a cut down in length, 27 mm SL100 intake valve and a new seat and special port.

 

Countershaft engine dyno is being built presently and some way off. The tracks tell me plenty. I don't worry too much about dynojet numbers; the units might as well be bananas or doorknobs. The graph is one from Kitaco's info and shows rear wheel output from the basic engine in the XR75 K1 bike. Different camshaft, much larger carb- dyno unit was 26 mm and a good exhaust and a bit more comp- probably 12,5:1 and you have a solid 18 to 20 hp.

006.JPG

005.JPG

212-1413811-2.jpg

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Seriously take a hike and host your own thread....

Posting up advertising fake dyno graphs from manufacturers out to sell parts is not a shred of proof of anything...never has been and never will be... Even so, it posts peak hp at 10k...which if you didn't know, is a long way off of 16k

Countershaft dyno always reads much higher than rear wheel... It doesn't take friction or inertia from chain and rotating massif rear wheel into account... So higher readings all around and means nothing of what reaches the ground... So you discount a dynojet dyno , which is the industry standard , and I have owned and operated 2 for many years... But a fake advertising graph is totally cool with you ,.as well as the fact that your own ass can give you detailed dyno numbers for advertising your own work..  sweet👍

Shifting at 16k?? Wow you are impressive...!!😳😳 That means that you can probably run it out to 18 or 19k in over-rev if 16k is the shift point... That's an amazing Honda 100 by any standard...💪💪

You keep taking pictures of the bowls and acting like they are ports...so lol right back at you...

Seriously , you can kiss my ass with all your BS of posting porting pics of just bowls, quoting big diameter valve sizes, and stories of big bore strokers running wonderfully reliable at 16k rpm....and saying the Spartan head ports are fantastic simply because you are clueless on how to engineer an efficient port... 

All while posting up pics of dyno graphs off WeB!ke advertisements and acting like you know any details of how they were derived....

Start your own thread and beat your chest all you want with your stupid pics and reposted dyno graphs drawn with crayons....

I will stay out of your thread where you can claim to be the God of 100's suffering while earthbound with mere mortals...

And I can continue sharing solid tech info... Posting good information and clear pictures and measurements... All on my super fun 130cc retro XR low budget trail bike here....

How's that sound for an accord, mate?!?

Edited by mixxer
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A bit more, probably, solid, different, can support, good, plenty good enough, And a few good blow ups....sounds great. 

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3 minutes ago, SteveThe Snakes said:

Put her in blow up mode. Like they say on the video. “Holly Chit” 😁

 

Good one right there Lol, 🤪😝👍🏻

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6 hours ago, mixxer said:

Seriously take a hike and host your own thread....

Posting up advertising fake dyno graphs from manufacturers out to sell parts is not a shred of proof of anything...never has been and never will be... Even so, it posts peak hp at 10k...which if you didn't know, is a long way off of 16k

Countershaft dyno always reads much higher than rear wheel... It doesn't take friction or inertia from chain and rotating massif rear wheel into account... So higher readings all around and means nothing of what reaches the ground... So you discount a dynojet dyno , which is the industry standard , and I have owned and operated 2 for many years... But a fake advertising graph is totally cool with you ,.as well as the fact that your own ass can give you detailed dyno numbers for advertising your own work..  sweet👍

Shifting at 16k?? Wow you are impressive...!!😳😳 That means that you can probably run it out to 18 or 19k in over-rev if 16k is the shift point... That's an amazing Honda 100 by any standard...💪💪

You keep taking pictures of the bowls and acting like they are ports...so lol right back at you...

Seriously , you can kiss my ass with all your BS of posting porting pics of just bowls, quoting big diameter valve sizes, and stories of big bore strokers running wonderfully reliable at 16k rpm....and saying the Spartan head ports are fantastic simply because you are clueless on how to engineer an efficient port... 

All while posting up pics of dyno graphs off WeB!ke advertisements and acting like you know any details of how they were derived....

Start your own thread and beat your chest all you want with your stupid pics and reposted dyno graphs drawn with crayons....

I will stay out of your thread where you can claim to be the God of 100's suffering while earthbound with mere mortals...

And I can continue sharing solid tech info... Posting good information and clear pictures and measurements... All on my super fun 130cc retro XR low budget trail bike here....

How's that sound for an accord, mate?!?

Your words below incur the wrath of the XR100 gods and the dozens of people who use Shift Up Spartan heads with good results.  Chest beating, hubris, world beating, reputation staking to da max

Now you are crying when a bloke who has actually built quite a few race XR100 engines bails you up and calls you out. Funny shit.

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mixxer said:

I have built race engines my entire life... Personally... For friends... For shops.. Commercially .... I'm only saying that for reference that I'm not unaccustomed to judging engine performance... If there's a faster XR100 based bike out there... I'd love to see it... I would line it up against ANY xr100 based engine with no hesitation whatsoever... This thing is more fun than a barrel of monkeys....🤘😎😁

 

 

I'd say that kidney trench combustion chamber and whatever you did to the good Shift Up ports and valve seat/bowl area cost you efficiency.  Having to advance the ignition timing 4 degrees is a clue to that.

Seeing you are a Dynojet fan I've attached a Takegawa sheet for several XR100 configurations.  The Kitaco graph I posted earlier is conservative and the Dynojet red curve is possibly a little optimistic at peak hp. In the real world, both engines at 145 and 146 cc but  slightly up specced still running on premium pump juice run with, or are faster, than modern 85cc MX two strokes- which inumerable tests over the last 15 years range from 20 to 25 hp- with cr 6 speed boxes.

Your engine would probably correspond to the blue line.

Your talk derisively and with almost total ignorance about ShiftUp and other valves.  I've included a photo of a couple of Ti. race valves from a 358 CI Windsor Ford race engine- an endurance engine that ran in Nextel Cup. (The rocker arm is from an XR100) The inlet valve is a full 6" long, the head diameter is 2.180" (55.3 mm) and the stem is 6 mm diameter. So much for your garbage about heavy heads on slender stems. These things were run flat out at 9000 rpm plus sometimes, for hours.

 But you've built race engines your entire life yet are unaware of modern valves- actually they are not that modern.

Stem diameters of 5.5 mm and hollow heads are now being used.

Takegawa 146.JPG

001.JPG

Edited by Momus
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Momus... You are a narcissistic blowhard and you are now boring me to death....

I would give you an education in valve geometry and flow, but you are still posting up crayon drawn advertising dyno graphs from WeB!ke as proof of your engine building prowess.... And saying that those Spartan ports are the bomb as delivered is the absolute stamp saying you don't know your ass from a hole in the ground about port design...

I'm not sure why you don't want to host your own thread to continue your chest beating untethered... Is has to be because you are incapable of hosting a thread anyone would be interested in so you have to piggyback on my thread....

Seriously.... You don't know shit about port design... Or much about anything else but spending a ton of cash and running on the simple platform of bigger and more expensive is better by default.... 

And you don't know that inertia goes up as the square of velocity... You saying a valve lasts at 9000 rpm doesn't translate into anything relatable to the impact energy at 16000 rpm... You hold up the dumbest shit as "proof"...

Post your own thread and pose away all you want....

You are boring me to death....

 

Edited by mixxer
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5 hours ago, mixxer said:

Momus... You are a narcissistic blowhard and you are now boring me to death....

I would give you an education in valve geometry and flow, but you are still posting up crayon drawn advertising dyno graphs from WeB!ke as proof of your engine building prowess.... And saying that those Spartan ports are the bomb as delivered is the absolute stamp saying you don't know your ass from a hole in the ground about port design...

I'm not sure why you don't want to host your own thread to continue your chest beating untethered... Is has to be because you are incapable of hosting a thread anyone would be interested in so you have to piggyback on my thread....

Seriously.... You don't know shit about port design... Or much about anything else but spending a ton of cash and running on the simple platform of bigger and more expensive is better by default.... 

And you don't know that inertia goes up as the square of velocity... You saying a valve lasts at 9000 rpm doesn't translate into anything relatable to the impact energy at 16000 rpm... You hold up the dumbest shit as "proof"...

Post your own thread and pose away all you want....

You are boring me to death....

 

Just out of curiosity, with the rocker arm and tappet design of the xrs, 16k rpm is impossible correct? 
the valve springs don’t return the valve fast enough?

or you would be dealing with valve float before you got to 16k? 

I got a few of those books you recommended and the more I read the more I realize I don’t know. but they have been very helpful in me understanding more of this stuff. 

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He states his shift point is 16k, so rev limiter must be higher still....

Correct, Inertia and flex of rocker systems lead to valve train instability at high rpm... That's exactly why cam actuating directly on buckets is the way high rpm bike engines are built...

Less inertia makes for less spring tension needed also... 

One of the best/ longest lasting valve trains of all time is the Yamaha 5 valve setups... 5 small valves , all made from titanium... Very light spring pressure needed to control... Less inertia slamming into valve seat... Shim under bucket followers/ direct cam actuation... 

 

Edited by mixxer
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1 hour ago, mixxer said:

He states his shift point is 16k, so rev limiter must be higher still....

Correct, Inertia and flex of rocker systems lead to valve train instability at high rpm... That's exactly why cam actuating directly on buckets is the way high rpm bike engines are built...

Less inertia makes for less spring tension needed also... 

One of the best/ longest lasting valve trains of all time is the Yamaha 5 valve setups... 5 small valves , all made from titanium... Very light spring pressure needed to control... Less inertia slamming into valve seat... Shim under bucket followers/ direct cam actuation... 

 

Next out of curiosity question, to achieve 19k rpm you would need a pneumatic valve train or Ducati’s desmodromic valve train system? 

Even if you made a shim under bucket engine rev to 19k, you would need a cam with low enough lift and long enough duration to avoid valve float.  

Which would negatively affect torque at mid rpm, giving you a flat spot? 
  Am I roughy correct or am I misunderstanding things?  
 

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2 hours ago, Bigfatredpig said:

Next out of curiosity question, to achieve 19k rpm you would need a pneumatic valve train or Ducati’s desmodromic valve train system? 

Even if you made a shim under bucket engine rev to 19k, you would need a cam with low enough lift and long enough duration to avoid valve float.  

Which would negatively affect torque at mid rpm, giving you a flat spot? 
  Am I roughy correct or am I misunderstanding things?  
 

No you are misunderstanding things. You would have seen through the years that every now and then one of these mystical, magical, laws of physics defying engines,  pops up out of thin air and does what no other can do. 
 

this is one to add to the list 

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No, you can make shim under bucket engines that run to the stratosphere , small and light components with multi cylinders per displacement...

But that has never been my focus for off road based competition engines, so I can't really help you in a quest for 19k info... That's momus xr100 territory... Which, by the way , is reported to be completely reliable after you have a few grenade💣😁🤔

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17 hours ago, Momus said:

Your words below incur the wrath of the XR100 gods and the dozens of people who use Shift Up Spartan heads with good results.  Chest beating, hubris, world beating, reputation staking to da max

Now you are crying when a bloke who has actually built quite a few race XR100 engines bails you up and calls you out. Funny shit.

I'd say that kidney trench combustion chamber and whatever you did to the good Shift Up ports and valve seat/bowl area cost you efficiency.  Having to advance the ignition timing 4 degrees is a clue to that.

Seeing you are a Dynojet fan I've attached a Takegawa sheet for several XR100 configurations.  The Kitaco graph I posted earlier is conservative and the Dynojet red curve is possibly a little optimistic at peak hp. In the real world, both engines at 145 and 146 cc but  slightly up specced still running on premium pump juice run with, or are faster, than modern 85cc MX two strokes- which inumerable tests over the last 15 years range from 20 to 25 hp- with cr 6 speed boxes.

Your engine would probably correspond to the blue line.

Your talk derisively and with almost total ignorance about ShiftUp and other valves.  I've included a photo of a couple of Ti. race valves from a 358 CI Windsor Ford race engine- an endurance engine that ran in Nextel Cup. (The rocker arm is from an XR100) The inlet valve is a full 6" long, the head diameter is 2.180" (55.3 mm) and the stem is 6 mm diameter. So much for your garbage about heavy heads on slender stems. These things were run flat out at 9000 rpm plus sometimes, for hours.

 But you've built race engines your entire life yet are unaware of modern valves- actually they are not that modern.

Stem diameters of 5.5 mm and hollow heads are now being used.

Takegawa 146.JPG

001.JPG

No I think that his line is purple or yellow, your   
propaganda chart has been purposely cut off at the top for some reason and it is not showing. Repost it correctly and you will see it. 😉

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1 hour ago, adnohguy said:

No I think that his line is purple or yellow, your   
propaganda chart has been purposely cut off at the top for some reason and it is not showing. Repost it correctly and you will see it. 😉

If you buy a case of snake oil you get the top half of the dyno chart 

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31 minutes ago, Bigfatredpig said:

If you buy a case of snake oil you get the top half of the dyno chart 

Rotella 

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14 hours ago, Bigfatredpig said:

Just out of curiosity, with the rocker arm and tappet design of the xrs, 16k rpm is impossible correct? 
the valve springs don’t return the valve fast enough?

or you would be dealing with valve float before you got to 16k? 

I got a few of those books you recommended and the more I read the more I realize I don’t know. but they have been very helpful in me understanding more of this stuff. 

16000 rpm using the standard Honda rocker arms is probably doable. They are a masterpiece of simple, effective design.  There is no constraint from valve spring design or material either and modern steel valves are up to it.

The engine that I run to 16K uses Takegawa aluminium rocker arms with roller cam followers and a conventional, standard Honda adjustment screw. The roller follower permits camshaft design that enables high rpm breathing without compromising the valve train. 

If I had to run the standard rocker feet they would possibly need to be coated and/or some properly high zinc oil run. Otherwise diesel Rotella is good.

Honda's mid 1960's 125 5 cylinder used steel springs and ran to a 20500 rpm redline reliably for GP distance. Today's engineers would consider the spring material they had not much better than coat hanger wire. Back in the early 1990's and still, Kawasaki's ZXR250 4 cylinder bike- and others were regularly and reliably spun to 20000 rpm; I think the redline was 18500.

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3 hours ago, adnohguy said:

No I think that his line is purple or yellow, your   
propaganda chart has been purposely cut off at the top for some reason and it is not showing. Repost it correctly and you will see it. 😉

What do you mean? Nothing has been cut.

 

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13 hours ago, Bigfatredpig said:

Next out of curiosity question, to achieve 19k rpm you would need a pneumatic valve train or Ducati’s desmodromic valve train system? 

Even if you made a shim under bucket engine rev to 19k, you would need a cam with low enough lift and long enough duration to avoid valve float.  

Which would negatively affect torque at mid rpm, giving you a flat spot? 
  Am I roughy correct or am I misunderstanding things?  
 

Japanese aftermarket people Takegawa has desmodromic cylinder head conversions for the XR100 horizontal engine cousins.

The head is readily adaptable to an XR100 if your interested.

Lest you get mislead by bloviating,  cam/bucket followers are still common in performance engines but proper modern high performance and almost all racing four strokes use the far superior finger follower design and have since late last century. 

The finger follower and cam/bucket 250 MX GP bikes run to well over 16000 rpm- I've been told by one engineer to as much as 17000+ with fair reliability. The Dixon UK racing 250 Kawasakis, developed by Cosworth were running to 16K in 2015 and using 3 speed boxes with a power range from 6000 rpm up.

Tak Mjonkey Desmo.jpg

Finger follower..jpg

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