Houstonderk

iTrader: (3)

[QUOTE=scathcart]Opening the exhaust port too early tends to cut into the powerstroke, which costs power. That's why we don't port downwards too much.

Racing beat ports open way too early and close way too early. These ports open even earlier than RB's.

So porting downward is just as bad as going up or what?

scathcart

.... 123 mm from the bottom of the engine is wrong. That would be breaking the port through the casting into the water jacket, and nearly cutting through the tension bolt jacket.
That would be porting up ~20mm.... not possible.

I was concerned with the opening line... the bottom one.

I'm not really trying to dump on your project at all, if it seems like it. (because of this and the RA seal report) Just expressing my opinion based on the engines I have built and tested.

scathcart

Porting down some is good.

Porting down too much is bad.



Confused yet?

Houstonderk

iTrader: (3)

Just making sure im getting it. How would you figure how much to port the intake to match the exhaust since you wouldn't want to go to big with the exhaust port?

scathcart

Experience

Flowbench and a degree wheel help too.

Houstonderk

iTrader: (3)

What the hell is a flowbench?

scathcart

The tool you buy/build to determine port flow in cubic feet per minute. Invaluable learning tool.

ddub

Oops, 23mm, my bad. I remember the 23mm part, but i just took off the tape from the template and it ripped the measurement off, just says _3mm

Houstonderk

iTrader: (3)

You got a picture? I always thought that of being something the big people have like balancing assemblies and lapping plates.

scathcart

Not handy, but I can snap one next time I head to the shop. Failing that, google "flowbench".

It IS something the "big people" have. But they're very simple devices and it is not hard to build one yourself.

iceblue

Houstonderk - You went racing with me last night, you could see yea I had to shift before 6k b/c of plugs but he pulled me between shifts when I had to build boost back up and that took till 4k to build 10psi. Since you are porting and we both know what were up against around here I am thinking you want to build your port to build spool as quickly as possible. Right?

Oh yea I suggest Mega squirt as well.

scathcart

I'm sitting here with a digital vernier trying to figure out what you're referring to...

23mm up is not possible.
23mm total port height is smaller than stock.
23mm downward is not possible.
23mm from the bottom of the engine is not possible.

I'm trying here

Next time you're in the garage, measure the port, and let me know, and I'll tell you your port timing.

Houstonderk

iTrader: (3)

Yea thats what im trying to get. So later on if i need high end i can get a bigger turbo and all to support it. It seems like alot of cars now are getting off the line faster and thats a pretty good advantage.

scathcart

Leave in the sleeve then. It won't exactly limit you for power.

Houstonderk

iTrader: (3)

Also the exhaust cannt be as big becaust of the 2mm bevel right? would that mean that whatever you would port it too yo uwould just add 2mm to it?

Houstonderk

iTrader: (3)

The n/a ones or swap to Tii?

ddub

Getting a picture off my cam as we speak, the 23mm mark was for lining up the template, sorry should've mentioned that.

EDIT
Here ya go.

scathcart

Swap to TII.
Takes some special work to get the N/A ones to work without cracking, though it is possible.

iceblue

Yea the cars are puting down TQ alot quicker then us and grabing that launch befor we build boost. On top of that a good % of them are lighter then us. No one will race us past 100mph so we need boost online ASAP.

scathcart

That's on a stock port?

That's not near as much as I thought then. Looked much lower in the first pic.
Can you measure how far down that goes anyway? I'll work out the timing.

Houstonderk

iTrader: (3)

Jess thats pretty far down. Is that how far it goes before the bevel?

scathcart

Antilag/nitrous on prespool & traction control will solve all your problems

Houstonderk

iTrader: (3)

Calm down. You know those civics are too light to go past 100. But yea thats the goal.

scathcart

I'll snap a bunch of pics and post them tomorrow. Its actally not that far down.

Houstonderk

iTrader: (3)

And what goals are going with this port?