[downest]

I've recently been reading up on porting, I'm going to port the other Y8 head I have and build another high-compression D16. Jared has also started working on porting the three A1 heads we have for the teg, but he's mostly cleaning up rough casting and smoothing the port-to-valve seat transitions. I read this article on Endyn's site, and I sent them an email a few days ago, but I haven't received a response yet, here is the email:

Hello:
I've been looking at your engine building tech articles for a while, and I'm planning to use your suggestions on my high-compression D16 build. What kind of aluminium epoxy do you recommend for use in the engine, that won't break down? Is JB Weld or something similar ok to use? Also, what do you use to open the main bearing holes up? It seems like they might shatter or crack easily, I've never machined them before. I'm also porting the head, it's a D16Y8 head for this engine, and my friend is working on a couple of D16A1 heads for our turbo 89 Integra rally/ice race car. For each application, how should we treat the dividers in the ports for each of these applications? In your article, you left it slightly rounded for "NA with occasional nitrous" use. The Y8 head will be on a mini-me running roughly 12.5:1 compression, with a stage 2 for now, soon to be stage 3 Crower NA cam, used for daily driving, frequent autocross, and occasional HPDE. It will never see nitrous or forced induction. The A1 is being built with PM6 (D16A6) pistons to lower compression slightly and boosted probably no more than 10 psi on either a T25 or a Mazda/Garrett IHI turbo. The integra head for now is going to remain stock other than the porting and cleaning up the chambers as per your articles. It's interesting to note that the casting in the ports of the A1 head is terrible, rough transitions and ugly casting marks extend pretty far back from the valve seats. One last thing, could you explain the practice of squaring the edges of the main girdle? I understand what to do, I'm just not sure I completely understand the benefits of doing it.

cheers
tom downes

The bottom-end work referenced is from this article.

Any insights? I want to get started on this soon, I've located all the parts I need. Now that I have a non-broken ignition system, this thing should put out some good power.

 

[downest]

Could someone at least tell me the kind of epoxy to use? Also I just got my other PM7s all together, they really need some cleaning. I know how to put rods together with pistons at home (Bart's oven/freezer method), but what about getting them apart, any ideas?

 

[signalpuke]

This link here is for mainly bike stuff, but it applies to cars too, he has some great port stuff, and a nice view on how a 4-stroke works. You have to scroll done towards the bottom for the links though:
http://www.mototuneusa.com/the_need_for_speed.htm
^^^He uses JB Weld and recommends it above aluminum epoxy:
http://www.mototuneusa.com/super_sonic_nozzle.htm

See if this stuff helps you out, they are links to some good constructive arguments about porting and polishing. Real good stuff, especially the last two.
http://www.eng-tips.com/viewthread.cfm? ... 000&page=1
http://www.eng-tips.com/viewthread.cfm? ... 346&page=7
http://www.eng-tips.com/viewthread.cfm? ... 27&page=20
http://www.eng-tips.com/viewthread.cfm? ... 10&page=76
http://www.eng-tips.com/viewthread.cfm? ... 93&page=10

 

[downest]

Awesome! One of my friends has linked me over to eng tips before, I just haven't browsed around much.

 

[RamaCrx]

Could someone at least tell me the kind of epoxy to use? Also I just got my other PM7s all together, they really need some cleaning. I know how to put rods together with pistons at home (Bart's oven/freezer method), but what about getting them apart, any ideas?

Just going to interject some thoughts................

1)The idea of porting yourself without a flow machine to test it seems illogical at best.
2)Epoxy on your head??? I'm not a metalugist but I would think that aluminum and plastic do not expand at the same rate. Sounds like a formula for disaster.
3)No disrepect to Bart, but his method involves juggling a burning hot piston and trying to shove a freezing pin into it and getting it centered before the temp equilibrates. You have one shot at it I am told. I'll have mine presssed in thank you..

Explain to me why I am wrong?

Richie

 

[signalpuke]

Yeah, infact, in one of those discussions they talk about the head that endyne just disclosed recently on Honda-Tech for their S2000. The discussion is from 2004, and he pretty much says what they did and why. Endyne says that they are going with a Mitsu engine next, they act all secretive about why it is better, but it is pretty self evident if you understand the fundamentals of how to maximize and control the air/fuel mixture in a cylinder. The Mitsu engine is direct injection and it is easier to "aim" the charge at the plug. Not to mention the fuel is better atomized and doesn't slow the intake charge, or impede velocity as the piston starts to compress. There are other factors as well, but it is pretty well discussed in the links :wink:
The Mototune articles are great, the guy has a great sense of humor to boot!

 

[rex2nr]

Could someone at least tell me the kind of epoxy to use? Also I just got my other PM7s all together, they really need some cleaning. I know how to put rods together with pistons at home (Bart's oven/freezer method), but what about getting them apart, any ideas?

Just going to interject some thoughts................

1)The idea of porting yourself without a flow machine to test it seems illogical at best.
2)Epoxy on your head??? I'm not a metalugist but I would think that aluminum and plastic do not expand at the same rate. Sounds like a formula for disaster.
3)No disrepect to Bart, but his method involves juggling a burning hot piston and trying to shove a freezing pin into it and getting it centered before the temp equilibrates. You have one shot at it I am told. I'll have mine presssed in thank you..

Explain to me why I am wrong?

Richie

The epoxy use referred to is what is done to the oil passage, to fill in a turbulent section of the pump. The pump is bored from two directions, and a plug is threaded into the side of the pump. Endyn suggests opening up the port going into the engine, and adding epoxy behind the plug to smooth out the flow from the pump.

 

[signalpuke]

1)The idea of porting yourself without a flow machine to test it seems illogical at best.Richie

A flow machine is an educated guess at best. I like the way it is broken down here
http://www.mototuneusa.com/the_8_phase_motor.htm

2)Epoxy on your head??? I'm not a metalugist but I would think that aluminum and plastic do not expand at the same rate. Sounds like a formula for disaster.
Richie

I am not sure about the plastic part you are referring to, please explain. If it was plastic epoxy you meant, I am sure downest was referring to an epoxy with aluminim properties, not a plastic epoxy.

 

[downest]

3)No disrepect to Bart, but his method involves juggling a burning hot piston and trying to shove a freezing pin into it and getting it centered before the temp equilibrates. You have one shot at it I am told. I'll have mine presssed in thank you..

How do they press them out at a machine shop? I have a hydraulic press... Anyway, with some welding gloves I'm not too worried about the heat/cold.

 

[RamaCrx]

They press them out with hydraulic press. I have one available also but the problem is having a guide the right size. We never seem to have it.

Back to the diy porting. I gained I believe 30 cfm with portflow design. Had the flow sheet. Now that does not directly convert into Hp gained, just potential gains. What will you have without a way to measure flow?
For me at least, this racing stuff is so often hearsay, personal beliefs, pipe dreams and promises, I like to at least have a shot at getting real gains that are somewhat reliable for a bunch of work I put in. Its called scientific method???

 

[downest]

But if I'm mostly just cleaning up the castings, I won't be taking off a lot of material. I won't even be using a cutting bit on the die grinder, just smoothing the rough castings and making the port-seat transition smother.

Anyway, I'll start a build thread soon I think... but I got the new block torn down last night.