Rear Transfer Port Epoxy Mod?

robertg · Post by **robertg** » November 24th, 2009, 7:30 pm

Has anyone tried this? I think it's from Eric Gorr's book.

'The hook angles of the rear transfer ports should be filled with epoxy so the transfers are aimed at each other instead of towards the exhaust port. The narrower the port, the sooner the smoother the low end power. The minimum chordal width of each rear transfer port is 10mm. Raise the exhaust port 1.5mm and widen the two ports 4mm on each outer edge.

100hp honda · Post by **100hp honda** » November 25th, 2009, 12:22 am

i think someone around here has the mo betta but ive never seen how well it runs.

yota · Post by **yota** » November 25th, 2009, 8:16 am

here is a pic of mine before I had it sleeved by Glen, it has some epoxy work. Is this what you are talking about?

robertg · Post by **robertg** » November 25th, 2009, 2:52 pm

yota wrote:here is a pic of mine before I had it sleeved by Glen, it has some epoxy work. Is this what you are talking about?

You can't really see the ports well in the picture. It's the two transfer ports right by the intake port.

100hp honda · Post by **100hp honda** » November 25th, 2009, 4:54 pm

yota wrote:here is a pic of mine before I had it sleeved by Glen, it has some epoxy work. Is this what you are talking about?

did you have to reapoxy it or was it not afected by the sleeve change ?

dubious01 · Post by **dubious01** » November 25th, 2009, 9:33 pm

the epoxy is suposed to go at the outlet of the transfer port, where the transfer charge enters the cylinder. You need to change the trajectory angle so it doesn't blow out the exhaust port.
Look at the angles of the transfer ports inside the cylinder, you will see which ones are supposed to be modifyied.

This is more important with the enlarged exhaust port changes especially.

I liked Erics porting, but ended up going a little wilder with my cylinder.
I was looking for more.

donovan35 · Post by **donovan35** » November 26th, 2009, 11:45 am

isn"t raising the exhaust port going to effect low end power? what kind of epoxy are you going to use?

dannygraves · Post by **dannygraves** » November 26th, 2009, 1:04 pm

this may sound stupid, but I used my garden hose to see exactly how the charge blows around all of the ports. the rears want to blow towards the exhaust except honda left a little lip that keeps them blowing at eachother, but creates a lot of turbulance. gorr talks about filling in that lip so you get the same desired effect without the turbulance. I widened the ports and blended the lip. more charge goes strait towards the exhaust which hurts low end, but when the pipe comes on and in higher rpms the thing is freaken wicked.

thestuz · Post by **thestuz** » November 27th, 2009, 4:57 pm

ive seen many people play with ports and i would advise against it. it can cause uneven turbulance and mixture burning problems causing large carbon builbups on the head and piston crown.
a cr5 engine is very evenly tuned for linear power,the way it should be. if you want more top end, do it the easy way and get a 250 ignition..

but yes, that epoxy resin does hold as lone as you use it on clean,rough surfaces. mske sure you use the one that is resistant to oils/high temp.they also have minimum thickness/thinness applications too i think.

100hp honda · Post by **100hp honda** » November 27th, 2009, 5:39 pm

thestuz wrote:ive seen many people play with ports and i would advise against it. it can cause uneven turbulance and mixture busning problems causing large carbon builbups on the head and piston crown.

wow you described brits motor to a T

http://www.youtube.com/user/500bigbore · November 27th, 2009, 5:50 pm

thats pretty awesome that the piston hit the head that much

100hp honda · Post by **100hp honda** » November 27th, 2009, 6:15 pm

brit tried to cut the squishband with a dremel

4Z · Post by 4Z » November 29th, 2009, 5:03 am

Devcon works good for that sort of thing.

blownbillybob · Post by **blownbillybob** » November 30th, 2009, 11:47 pm

i've used JB weld and riolo, eric also says to use a 39mm pwk and a after market pipe i think a gnarly,you can also take 1.5mm off the bottom of the cylinder for more off idle torgue and a harder hit in the mid and still have lots in the top end.but your also going to have to do cyl. head mods to run on pump gas.its alot of work but well worth it if you do a nice job i use this on my trail bike and hillclimber!!!!! but i only took 1.0mm off the bottom and the exhaust to start with,and the last one i did for my brother -n-law i only took .50mm and did minor head work and runs fine on pump!!!!!

http://www.youtube.com/user/500bigbore · Post by **Roostius_Maximus** » December 1st, 2009, 5:38 am

so taht was .020" of machine work, did you also switch from oem to cometic base? thats another .010" i think (left my spec book at work)

hes using the gnarly to be low rpm rippy, the lowering of the jug make the powerstroke longer, more torque

britincali · Post by **britincali** » December 1st, 2009, 9:51 am

100hp honda wrote:brit tried to cut the squishband with a dremel

Brit FIXED glens fuk up with a dremel

100hp honda · Post by **100hp honda** » December 1st, 2009, 4:42 pm

dremels kickass

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Rear Transfer Port Epoxy Mod?

Rear Transfer Port Epoxy Mod?

epoxy