The "best" cylinder!!!
- Thread starter joeak47
- Start date
How closely does one side need to match the other? It looks like since the mix is coming from 1 source and going out 1 exhaust port that it would have little effect if one side of the intake ports or one side of the transfer ports is a little different from the other side.
Everything should be symetrical as possible. In other words the same on both sides. Thats why the porting templates that John makes, keep things symetrical without guessing. I see that the picture I posted looks like one intake ports is different on one side (the right),but its the picture and the angle I took it at. Everything is symetrical/equal.
Here's the crappy picture I'm talking about...
Here's the crappy picture I'm talking about...
Everything should be symetrical as possible. In other words the same on both sides. Thats why the porting templates that John makes, keep things symetrical without guessing. I see that the picture I posted looks like one intake ports is different on one side (the right),but its the picture and the angle I took it at. Everything is symetrical/equal.
Here's the crappy picture I'm talking about...
I saw that, that's what got me thinking but looking at the picture taken from inside the cylinder, it's clear that the ports are matched. Most of the pictures I've seen that has the 2 little holes drilled through on the sides (boysen ports, boost ports ?) look like they vary quiet a bit in size and location but I don't remember what they look like from inside the cylinder.
Yes, that's what I said "......but looking at the picture taken from inside the cylinder, it's clear that the ports are matched........".
It is very critical.
Here is a head from and engine my son picked up recently:
(front is at the top)
Notice the very offset burn pattern? Bad stuff.
This engine had a lot of problem, including a head gasket leak (see it?),
but worst was the twisted liner. This would be an absolute power killer.
The intake mixture coming into the cylinder and chasing out the exhaust is a critical performance.
Unbalance it and you lose a lot of power. The transfer ports aim and balance is so very important.
The exhaust and lower intake ports not so critical.
Best, I remember when TripleCrown posted pics of this cylinder. Were you able to figure out if it was installed twisted or twisted during use?
The uneven burn pattern on that head is no doubt due to the "swirl" induced by the twisted sleeve blocking part of the boost port. Notice that the clean. uncarboned part of the head would be sitting on the right side of the quad where the "twisted" boost port would be aimed at.
The fact is that the two lower intake windows never even get near the combustion chamber and the two windows in the piston partially block them at times during the stroke. Those two ports being ABSOLUTELY equal in all regards isn't as crucial as having the exhaust port roof evenly curved, the boost port properly aimed, and the transfer ports properly timed. Obviously having one HUGE and one tiny will affect the charge balancing going up each side of the transfer ports and could cause problems with scavenging but a tiny imbalance will never be seen.
Chamfer only needs to be minor to break that sharp edge so it won't snag a ring. Too much and you're beginning to get into an inferior gas seal at the port edges and you're starting to "muddle" the intended port timing.
Cylinder looks really good Joe. We definitely need a ride report!
Haven't messed with it yet. He is working on a Honda at the moment.
Looking to get it out of the garage to do some serious Blaster exploration before the snow hits.
All in good time.
Definitely not chamfered. Very poor job of cylinder work.
Just call me Steve...
It mic'ed out nice... And YES! those are cast pistons you see. When set up properly they work perfectly! I have always ran cast pistons with ZERO issues. Even with "aggresive desert" porting,high compression/re-chambered head work,OIL INJECTION (you read that right),etc,etc
Last edited:
Maybe more likely that the lopsided burn pattern has something to do with the leaking head gasket.
The boost port pushing more fresh charge to that side of the engine will greatly increase the "pressure" on that side of the head when the ignition event happens. The leak occurs when the explosion reaches the edge of the head and is then forced to push the piston down. It'll take the path of least resistance if it can and if that's out of the gasket instead of pushing the piston, it'll go there. Couple more fresh charge on that side with maybe a loose head nut and BAM you've got a blown head gasket.
Joe, that's a mighty fancy bore gauge you got there. Is that a Cutwel?
No. they're SPI.
I have and use many different brands,but these are by far my favorite. I do auctions all the time,and thats where I won these. They are like $3800 a set (true but ridiculous),but I was lucky enough to get them for $11 (not bragging). No body wanted them,because they had no idea what they were for. They come as a set of four,but one of the electronic heads was missing.
I say "big deal",because the electronic heads are interchangable with each of the micrometer heads. They even have the calibration rings. These beauties guarantee me nice strait and round bores. They're a joy to use. Tri-lobal bore gages are super accurate!
Here's a picture of the set. They were lightly used. The calibration rings are a work of art. Its really cool to calibrate the tool (20 degrees celcius),then hold the calibration ring in your hands to increase its tempurature,then measure it with the bore mic. Its amazing the change just the warmth of your hand can do to a piece of metal. I really don't need anything that has a resolution of 1/2 of a 100th of 1/1000ths of an inch,but its fun to see how close you can get everything when honing a cylinder. I can say that my bore jobs turn out rather well (accurate)... and always have.
I know how much they are which is why I commented 
I:I.
While looking for bore gauges I looked at the full spectrum including the Cutwel 3 points (I laughed my ass off when I saw the prices!) so I ended up settling for a Dyer 2 point dial gauge that goes to .0005" (simple, old fashioned bore gauge) I got very lightly used and complete for $50. Obviously not the ridiculous steal you got on those, but I thought it was fair.
Nice set and ridiculously good price. Why is it all of the deals are elsewhere?!
I:I. While looking for bore gauges I looked at the full spectrum including the Cutwel 3 points (I laughed my ass off when I saw the prices!) so I ended up settling for a Dyer 2 point dial gauge that goes to .0005" (simple, old fashioned bore gauge) I got very lightly used and complete for $50. Obviously not the ridiculous steal you got on those, but I thought it was fair.
Nice set and ridiculously good price. Why is it all of the deals are elsewhere?!
Mr. Best... Your package showed up today and you weren't home to get it! 
Bummer! Lots of cool stuff in that box! B)
All ready to bolt on and go! I:I
"Priority Mail International Parcels
Addressee not available - Addressee advised to pick up the item
December 03, 2012, 8:32 am
CANADA"
I hope that notice dosn't blow off your door.
Bummer! Lots of cool stuff in that box! B)All ready to bolt on and go! I:I
"Priority Mail International Parcels
Addressee not available - Addressee advised to pick up the item
December 03, 2012, 8:32 am
CANADA"
I hope that notice dosn't blow off your door.
I don't get it Joe? What are you trying to say? HA! You crazy big scripted joker you!
I blew coffee out my nose when I saw this, pulled my slippers on and ran down the post office.
Look wonderful Joe! Amazing work. Now, how do they work???
They've come at a good time, snow has melted off, weather warming. Neil's Honda ready to pull out of the garage.
I have 24 hrs of work to do in the next 36hrs, but I see the test coming Wednesday.
Again, thanks Joe,
Steve
I blew coffee out my nose when I saw this, pulled my slippers on and ran down the post office.
Look wonderful Joe! Amazing work. Now, how do they work???
They've come at a good time, snow has melted off, weather warming. Neil's Honda ready to pull out of the garage.
I have 24 hrs of work to do in the next 36hrs, but I see the test coming Wednesday.
Again, thanks Joe,
Steve
