thats what i thought when i first saw the ports, i also thought that they are not porting much. maybe its a tiny steet port, just to remove the rough casting. we need someone to translate that text to speculate.

 

HTey matched the port up to the sleeve. You can see a lighter coloured 'lip' on the before shot that is gone in the after.

 

ahhh, I see.

 

I think ito needs to find a customer in japan so he can send one over and do some engine dyno comparisons.

Or vice versa

 

There are a few things I have noticed being different here in japan then the US. The intake ports are smaller here then the US and the exhaust ports are bigger here then the US. Have to remember the drivability requirements here are different then the states. 95% of the local people do not work on there cars so they go with something that will last longer then make more power. Also gas prices here are over a 1$ a liter and there cars are daily drivers.

About the porting styles here verses the states, I was told long ago that you can not eat if you can not ****. I see so many pics of huge intake porting from the states but yet there exhaust ports to me are small. In general I see intake ports increased 30-50% but yet the exhaust ports are only increased 20-30% in the US. Why is this? I remember back in the early 80s, we would only port the exhaust and rejet the secondary jets would increase power with keeping the car very drivable and pass strict emissions test in Japan. I've seen some porting template here in Japan and there small exhaust port is to the diffuser (spec1). There spec 3 exhaust ports are large. I am in the prosses of building a motor to there recommendation and run the same set up as I ran in the states. Only thing different will be the motor porting. In two months I will be done and will post my results. Let me say this, I am not sticking up for the pic shown on this tread but am trying to understand why the different porting styles between Japan and the US. I don't criticize there differences but try to understand why they are so different. Why?

chuck

 

I`m not quite sure, but you can port the intake ports to the middle between the oil seal track without burning to much oil. a friend of mine did it on a 12a turbo engine,and it worked pretty well. Once in a while you could see a "blue puff" from the exhaust, w3hen vhe was shifting gear at the rev. limit.

He told me there was a slight increase in oil consuption, but nothing to worry about.

I think it braked 322hp with a t04 or something..

 

Like it says...it all depends on the use of the engine

 

Ok in the Amemiya Picture the secondary ports part....... the one on the left is marked for porting and the one on the right is after porting. The caption says "mizu mawari ga arunode kore iijo hirogerarenai". Meaning becasue water flows around this area they cannot make it any wider.



The exhaust ports are ported up 3mm and looks to be even with the diffuser on the bottom and sides. The one on the right is the ported one.



I am with chuck on this one....about as many people you talk to you get that many different answers about porting. I think it all depends on your experiences with these motors. One noticeable trend in Japan is smaller sized intake ports for normal sideports. You see few bridgeports and even fewer perephrial ports. However almost every shop does them and they even do cross ports where a hole is cut into the rotor housing like a perephrial but the normal side ports are also incorporated. They sell special crossport manifolds and all. When talking to Rmagic about putting together a motor to turn a TDo6 206 for drift and circuit use he said small sideport nothing on the exhaust will be fine for a broad powerband and 400hp peak. Going on my experience and what I thought was a normal sideport we ported the engine and took the housings back........he said was large for a TD-O6.....I thought What!?? I also took the liberty of porting the lip on the bottom of the exhaust to make it flush with the diffuser. When I showed him that he said well in that case bring the top of the port up just a little higher and clean it up some.



After going over the Judge Ito threads here and other resources as well I realise that my sideport is pretty big......hehehe I am running it now with a tune done by me on my PFC and the turbine spools GREAT and pulls hard past redline. I honestley am in over my head when it comes to building an engine and getting the most out of it with porting and turbine and the whole balance thing. I have some more templates in RX7 magazines that I will scan and post later on today.....maybe we can learn some more.

 

Interesting stuff no less. Thanks!

 

Very useful. I can see how they build them to their needs and why they do that, it just makes sense. Thanks for the pics.