Topic: JMR Honda cylinder head Stage 4+

[johno]

To get this you have to do the following,

[johno]

Lots of machining and Understand epoxy

[johno]

More machining and innovation.

[johno]

SO .....   How good is this head.

There has been a bit of chit chat lately about who does what and how good is what.  I have spent two years searching the globe for the best available Honda head, I have a strong background on the subject and have spoken to a lot of gurus over the last two years before settling on asking Mike to do a head for me.  I have lots of reasons for asking Mike  and I am glad he accepted the challenge.   He committed to the project and I never had to contact him once asking the old hows it going when finished stuff, not once. Mike sent me photo updates and nailed his delivery time in the best packaged item I have ever seen.      In over 40 years of High performance industry this has never happened to me before I am still in shock.

 So did I get my money's worth ?  Sure did.    Well its the best head I have flowed

[johno]

I'll post some info on the results as it may interest you.

Lets say There two catagories for modified CB 750 Honda ports,

Standard Honda inlet ports
Lets say the best numbers posted are Jerry Branch 75cfm  @ .400 , Larry Cavanagh 78cfm@.400

Hi Rise inlet ports
Johno ( me) hi rise inlet 74 cfm @ .400 then 83cfm @ .500  ( no cams available)

I have spoken to at least 3 other worldly respected porters and around 75cfm @ .400 is the going rate , top dollars for that number.

[johno]

Well here are the numbers , as you can see you guys are looking at a very special head. 

The .400 lift rate is pretty cool hey, but let me tell you,  the lower flow rates are just unbelievable......

Dont beat me up too much as when I done my hi rise the old flow bench was just a dream and the low flow rates are as a result of big valve stem and a deliberate sacrifice for bigger rates at high lift.  Mikes head just makes mine look like #$%*..........At the risk of repeating myself , well done Mike and thank you !

[johno]

Remember this is a stock inlet port that can make life easy for fitting carbs injection etc.
What is so different with Mikes style.................amongst a few other things..... the floor.

I have attached a drawing from a Vizard porting book which really illustrates what he has done in stages.
His goal get the port hi up then turn it down for a straight shot at the back of the valve, that opens up flow around more of the valve not just sliding through the back half. he then offsets it the best he can to help push the flow to the unrestricted  centre of bore and swirl for fuel in suspension.

His idea of raising the port floor and how he done it,  to send the inlet air high into the port and help the inlet air turn down to the valve is just awesome.   
ciao johno

[johno]

Oops , try this for the port style and changes.   as per last post

[johno]

How good are this Kibblewhite valves, I am amazed, also the cycle x beehive springs with the Nascar coating , check them out compared to a normal 34mm valve and S&W double valve spring.   mate cant believe it.
Any way thats enough from me on this subject, I felt Mike should be given the Kudos he deserves, Thanks mate, you dun good.
cheers johno

[Bill/BentON Racing]

Wow! I knew Mikes heads worked. I've got two and one on the way. I( might not mean much) believe Mike is the best. Especially on our old SOHC's. the man cares, loves and enjoys what he does. And he does it WELL! Without Mike Samauto would still just be pile of parts. Mike, Merry Christmas and yes I am blessed to be here first and have friends like Mike and y'all . johno, remember erections lasting longer than 4 hours call the doctor....or wife's sister! Bill...or hide that head! 

[Sam Green Racing]

Sounds better than VIAGRA... AWESOME work MIKE as USUAL. 

Sam.

[bwaller]

And you wondered why he needed to turn work away for a spell, cool work but draining I expect!

Congratulations Mike and well presented johno.  I'll agree, every detail of his work, including the return packaging is over the top.

[joe p]

WOW! nice head. I would like to see the 1320 numbers with that head on a 1000 with about 300lbs of compression. (Set up for drag racing)

[MRieck]

Thanks for the kind words Johno....it is very much appreciated. Same to you other gentlemen as well. That kind of support gets me in the shop after working 2 jobs.
I was happy to see Johno's #'s especially the low lift figures. the thin stem, backcut intake valve/tapered guide, wide,flat floor and seat/throat boring all enhance those #'s. There is a lot of work and thought into that head and I do not think it could go to a more deserving individual....I truly hope it helps achieve the primary mission for which it was built. Go out there and kick some a$$ Johno!

[kmb69]

That is unbelievably beautiful work, Mike. Very impressive numbers. Thanks for sharing Johno.

PS. Glad to see you're out of that beanbag this morning, assuming you don't have a wireless keyboard.

[Jim F]

sense I have mikes head on all of my in-line 4s, (3 bikes) I guess  I will have to pull off the heads on the RC51 and see what he can do
(Interested Mike) but lets make it next spring or so
good work Mike
Marry Christmas Mike and all of my friends

Jim

[KayOne]

Wow! Impressive, can't wait to see how much power it will give you. Is it based on a 410 casting?

[Jerry Rxman Griffin aka MuthaF'er]

Damn you guys, now I'm gonna have to get off my ass and go get that gallon of oil, prime the oil pump and install and see what my JMR Stage IV head will do  . While I don't have access to a flow bench I'll be glad to just use those numbers too. Wish me better luck this time. Yeah, Mike kicks ass.

[TurboD]

Nice work and numbers. Its good to see some actual numbers associated with these old heads, they help to give some idea as to just how much power might be expected.

[MRieck]

Nice work and numbers. Its good to see some actual numbers associated with these old heads, they help to give some idea as to just how much power might be expected.

Thank you. That head is built for LSR...I normally would not put epoxy on the floor unless I knew it was going to have limited time on the street. In that case....well... To be absolutely honest and fair johno's high port #'s would easily reach and more than likely exceed my #'s IF he used the same hardware AND used the same machining methods. It was VERY much different when he did that head 30 years ago. Boring those seats and throats is a big key. I also had my machine shop push that 45 angle to the edge of the valve. Once again....purpose built head...normally I would not do that for a street head (unless somebody really wants it.)

[Bill/BentON Racing]

On those heads is there a charge for all the epoxy?  Bill

[bear]

Nice job Mike.
If it gets the Johno seal of approval thats good enough for me.
Tech savy blokes like yourselves pushing the envelope keep boof head "historic racers"  like me on the straight and narrow and it's much appreciated.

The heads on both  our motors have reached the end of their service life.
Uncle Billy has couple of 410's socked away in the "Bat Cave" for me.
Now I have some options!

Cheers,
Brian

[Bill/BentON Racing]

Bear, just waiting on you. Cheaper to ship to Boston than down under!! Bill

[johno]

Bill,
speaking of shipping, got my rubbers thank you.   6 days thats quick. 

[afkrejci90]

What does the epoxy on the floor accomplish?

Sent from my Nexus 4 using Tapatalk