need help on choice

[joeak47]

It was 100 psi and its now 75 psi??? I say "Hmmmm"...
Did you do the compression check properly?
When doing the compression check,did you keep the throttle wide open during the test?
Did you work the kick start until the needle stopped moving?
Was the gauge screwed into the spark plug tightly to prevent leaks?

Before we go any further with this...
How many CC's does the re-chamber "toroidal" head CC at? The reason I'm asking,is because I've cut MANY toroidal heads for yamaha blasters,and by looking at the depth of the cut on the other heads he's done,they look to be VERY deep,which = large CC combustion chamber. This WILL lower your compression. he states that they're "approximately 20cc's". That doesn't cut it. I can guarantee you its MUCH more that 20 CC's! The heads I cut for "Best " were 19.5 CC's. Both a "Hemi" (my favorite) and a "toroidal" (my second favorite) and I had to take ALOT of material off the entire head of the "toroidal" to get it to 19.5 CC's. My guess is the head you have is like 25 CC's + . This will cause your drop in compression! Right off the bat by looking at a picture of it (in the for sale section) I would say 27 CC's or possibly more. A stock head is 23 CC's. Did you CC it yourself to check? Its easy to do,and you will be able to get the measuring down to tenths of a CC.
If your not noticing a power increase...Hows your jetting? Thats a "Big one".
I would go back and do a compression check,and get some new readings. You may have made a mistake. If your compression is still 75 psi,swap the stock head back on and test again. That should show where the difference is.
Also... Don't be afraid to try a different compression gage. I've had a bad one before.

QUOTE..."Sorry Joe couldn't wait"
I hear ya,been there,done that....but situations like this is where I say...
A little patience goes a L-O-N-G way!
My turn around time is (literally) two corona's and hour and a half of time which includes PROPERLY CC'ing the chamber plus of course shipping time for "priority mail". Couldn't wait? Wow. Most shops give a lead time of 10 days to 2 weeks not including shipping time
(except Ken OConnor... he's quick).
Your patience has to come into play somewhere.

You still have to get that toomey pipe on on your bike. Don't start talking about swapping out a pipe that you didn't even try yet. Thats ridiculous and expensive. trust me!
If you already have the money for a different pipe to replace the toomey you still haven't even tried yet,....you had the money for my porting and head work. Think about it.
Cheaping out on porting, but already wanting to replace a pipe you have yet to tested makes no sense.
Slow down... You need to get everything "Tuned" and working in unison. Not start buying more mis-matched parts.

Your going to like that toomey. It will work well for you,if you do your part. The pipe and a properly re-chambered head will really wake up your blaster!BUT... PORTING IS KING! End of story.
If I were you,I would CC that head,and compression test with BOTH heads,and see what you come up with.
Post your findings here,so we can help. Pictures too.
Just think... by now you could have been ridng your blaster with a proven
"Aggresive Desert" ported cylinder and re-chamberd "Hemi" head".
Now you've got to fix things..
Report your findings,and lets see if we can get it dialed in. All is not lost.[/B]

Here's a 19.5 CC "toroidal" I did for Steve (Best). You can see the depth of the cut that I had to take to get that size of chamber It was quite a bit...

 

[snake61047]

I know I get into a hurry way to much. I think its the head just by looking at the depth of the chamber. Im gonna retest first. And no I don't have the cash. Id have to sell my set first. I have a new gasket coming later this week and Ill try a different gauge. Yes it was wot and I even lubed the rings with two stroke oil on the 2nd try. 75 was the max no matter how many times I kicked it. I checked the plug and it looks great. As I said it has been upper 40's lower fifties here. I am gonna port it. I just am gonna wait until I have a reason to tear into the motor. Your head looks a lot shallower than his. If it is the head Then I will be senting my stock one to you. How it the hemi's powerband vs. your toridial

 

[joeak47]

I prefer the "Hemi" for the top end scream. Still works good in the low and mid range too. Without porting your just cheating yourself out of alot of power..... Regardless if its mine or someone elses.

Here is the Wwholden head. See how deep the chamber is? This is why I would CC it to verify its size...

 

[Racer51]

saw for sale thread what whould a hemi head look like since those two are so different?

 

[joeak47]

It would look like this...half a sphere...

 

[snake61047]

im going back to stock for now. I have no top end power anymore. I can't pull 5th gear. When the new gasket comes im gonna put the old head on. I am looking for top end. I really don't want to sacrifice low end but I don't need it improved. WEhat would you recommend joe? Im starting over with the exeption of the Toomey system. After I cc the head Wednesday I think me and Wwholden are going to have a talk.

 

[joeak47]

. You can't pull 5th gear?!?? Thats pathetic!
Something is obviously NOT as it should be.
I gave you my recommendation earlier... My porting and head re-chambering. PORTING IS KING!
You'll thank yourself later,because...

They're a matched set. They're proven. They work VERY well. They have longevity. They offer extreme reliability. You will be right at double your stock output with that toomey and STOCK carb. You can up grade to a bigger carb,reeds,etc,etc as you see fit when you feel the need.

Let me know when your ready.

 

[Blaaster]

I just put a tordioal head on my bike today from Wwholden. Sorry Joe couldn't wait. I have jetted for the removed air box lid and premix. The plug looks good at 40 degrees. I am looking to put boysen reeds in at the same time I put the pipe on.

Joe I can't wait to get my cylinder ported. Id love to have you do it. It seems like I lost compression when I installed the head. I was getting 100psi cold before and now cant get above 75 psi. I haven't really noticed a power increase either. I did notice a harder kick though?!?!?! go figure. I haven't rechecked the comp with the engine warm. I went to Yamaha for a new head gasket before the install and they gave me the wrong one. I told them which one it was as they were digging thru their box of open gaskets. they thought it was too big. So I used my old one for now. I called and let them know they messed up. I live 45 minutes away from them so they are going to mail it to me for free. I'm hoping the Toomey will help with top end and the tordioal head will help in low mid.

Maybe this could explain your problem, 100 psi is borderline.



Follows is a write up on a wwholden toroidial cut head that I fitted last week, could not be happier with it.

However the toriod did look a tad large, I did not cc it, nor check the compression, I might just have to pull it off and do a cc test.
….......................................................................................................................................

Fitted the head earlier today, did the required heat cycles and re tensioning.

Reset the timing to stock from +4 deg, fitted a brand new b8es spark plug.

We run a DMC Alien pipe and nothing more than a polished exhaust port and a foam filter directly on the carb throat.

I have not ridden it yet, but my lad has.

The first thing that was noticed was a crisper exhaust note, I also noticed that the header too had a more pronounced ring to it ( definatly not detonation, I know perfectly well what sounds like).

After warm up, the lad took off and it seemed to be running a little rich on the needle, but cleared up when he really got on the gas.

The idle had to be readjusted as it idled about 500 revs lower than the stock head.

Owing to the soft ground the lad could not get to WOT as he could not get traction.

He informed me that the power was coming on about the same rev even though it was now at stock timing.

The power had increased a great deal and held well right up to way past where the powerband faded with the stock head.

We will have to wait a while until the ground dries out to be able to get a WOT run.

Even at 1/2 throttle holeshot on soft turf, the front was just about impossible to keep down and the lads rear end was propelled toward the back of the seat.

Normally he would have to physically move his butt back, but the added acceleration of the new head pulled him back with no effort on his behalf.

The overall impression of my lad was a nod of the head, a big wide smile and a " Thanks Dad I love it".

That says to me, if you want something to put a smile on your face in the way of a power increase, a rechambered head is just the thing to put one there.

We will have to wait a while for the ground to dry out before any WOT runs can be tried.

 

[PRChrist]

Buy a toomey is the best pipe for a blaster

 

[snake61047]

Alright. Pipe came in yesterday. Today I leak tested the engine with the new head on. Engine is air tight with no loss in psi. Did a comp check with another gauge. Same 75 psi max. switched back to stock head and retested comp and got 100 max and 75 with first kick. I am going to cc the head later tonight. I want your head joe. after I cc the head im gonna get with wwholden and see about a refund. I cant afford the porting right now. I understand what you are saying about it being king. Im at my spending limit until I can get more ot. I know Toomey says use a 310 main jet but in my experience that is way too rich. What are you guys running for mains? I have no lid and stock head on right now. I got a 270 290 and 300. They didn't have a 280.

 

[Larry's Shee]

So you know more about jetting needs than the pipe maker? Though they probably recomend more on the safe side, better fat than fried.

JMHO, your results may and will vary.

Word: plug chop/read.

 

[snake61047]

lets put it this way. I have a 290 in right now and it is still way rich its boggy on the top end. They will always side with richer. No risk. Slp recommends 400 mj on my sled and it ended up being set at 360 at 0 degrees.

 

[snake61047]

ok guys, I cc'd the head today and if I did it right I came out with 30cc's. That's a far cry from the 20 I was promised. I read sicivicdude's article on head design and I understand it. With wwholden's design he didn't put a ramp in for the flame to change direction from linear to vertical travel in the chamber. It does a 90 degree angle from the roof of the chamber to the side. This bothers me and makes me think it would disrupt the flame travel. As I said before it measures 30 cc's. Could I and would it be worth my time to add material to the chamber to change it to a 45 angle instead of a 90. I could tig weld itit would also reduce the side of the chamber. Im just not sure how much weld to put in.

 

[joeak47]

30 CC's???! I knew it was more than 20 CC's just looking at the picture. I said it looked to be 27 CC's or more. WOW! It was more than I thought.
QUOTE... "Could I and would it be worth my time to add material to the chamber to change it to a 45 angle instead of a 90. I could tig weld itit would also reduce the side of the chamber. Im just not sure how much weld to put in."


You could,but in my opinion its not worth the effort. It would be much easier to just start with another stock head and start machining a proper combustion chamber.
That and porting.

 

[snake61047]

you keep saying porting and I hear ya. I know what id gain but money is tight enough as it is. im going to see about a refund. do you have any heads ready?

 

[joeak47]

you keep saying porting and I hear ya. I know what id gain but money is tight enough as it is. im going to see about a refund. do you have any heads ready?

I can have a head PROPERLY machined,properly CC'ed,and PROPERLY packaged in a "Medium" flat rate USPS "Priority Mail" box in under two hours. No I'm not pulling your chain. Port work will take longer,but thats fairly obvious. And.....My work is done correctly.

 

[joeak47]

That includes a tracking number.

 

[snake61047]

That includes a tracking number.

I pm'ed you I:I

 

[Racer51]

BTW joe I subscribed and downloaded all 10 vids to my laptop and plan on taking a full colledge corse in machining in the fall. it covers all from CNC to computer mapping to lathe work to just about everything bummer is I gotta take a full year of book studies then I get to do the fun stuff but lucky me my grand pa has a real nice older lathe