i have see that lazy don have a lot of knowledge about heads!! well i can`t wait to have my car and test it!!!

By lazy (165.228.57.19) on Tuesday, October 05, 2004 - 06:08 am:

hmmm.. maybe that was what the guy was talking about. *shrugs* we may never know. I searched the archives and came up with nothing. He talked about boundary layers like Keil mentioned.

Anywho Felipe: Don's the man - listen to him

By Don (199.2.139.239) on Tuesday, October 05, 2004 - 05:40 am:

I didn't post that I dont think I ever read that one. The only reason not to have a smooth exhaust port is if there is a poor port shape and your trying to use turbulence to make the usable port smaller or make it unstable so it turns out the exhaust port better...neither one is present in a eb head. As a general rule you want to keep the exhaust port small and smooth it helps! A general rule if you dont have a flow bench is dont touch the floor of either port! Smoothing out the sharp edge right below the valve seats is the best gain.
Then maybe raise the roof of the intake a bit on the eb2 head around the valve guides if you are very careful. DO NOT make the gasket matched "bells" at the begining and end of the ports most people do.
Thats about all I would do with out a flowbench and cylinder adapter for a 1200.

By felipe casanova (200.30.231.18) on Monday, October 04, 2004 - 10:05 pm:

believe i searched the forum and i didn`t find it too

By lazy (139.130.237.102) on Monday, October 04, 2004 - 07:35 pm:

There has been a post on this board discussing this exact thing. I think it may have been Don who gave a really good write-up/explaination about it.

If I remember correctly - you never want a port to be perfectly smooth. On the intake side a relatively rough surface creates a turbulence that helps with fuel atomization - as schnitzel said. On the exhaust side you want some surface irregularity/stippling/whatever as it will INCREASE the gas velocity due to what I call the 'golf ball effect' - I won't try explain it because I'll probably get it wrong.

I've just tried a quick search for the post and didn't find anything. If you can't find it yourself then the post is either in the archives or was lost in the crash.

By shnitzel (24.66.80.104) on Monday, October 04, 2004 - 05:36 pm:

my general idea has allways been to polish the exhaust side and the chamber (helping the ehaust out quick and the explosion across the chamber run smooth), but rough up the intake runners to help atomize the fuel.

By felipe casanova (200.30.216.170) on Monday, October 04, 2004 - 02:21 pm:

first time that i hear that is no good polish the ports to smoothness, it`s supposed that with a softer surface the gasses should flow more fastly because the roughness wouldn`t stop them, so now i`m pretty confused about what to do

By Keil Shepherd (Medicineman) (213.122.101.3) on Monday, October 04, 2004 - 12:19 pm:

Hey Felipe

Don't polish the inside of the combustion chamber too much! It might sound odd but a rough surface in there will break down the boundary layer between the gas and the head and so make the gasses flow faster. I remember seeing this TR7 head that had been polished inside until it was like a mirror but the race prepping guy had to grind it rough again to get some decent swirl

By felipe casanova (200.30.216.170) on Monday, October 04, 2004 - 10:40 am:

thanks for your precise explanation don and bryan! i read previously in other topic that the Eb-2 head will give me more "neck move" and the Eb-3 more peak rpm`s, but well im gonna put my Eb-2 head and i`ll do it a little polish and porting, but a lot less than the EB-3, this week is going to be ready and i let you guys know because before the head gasket gone the car runs great and without a decent exhaust and header, so i guess that it`s going to be gain (should be) im going with 1.75" with the mugen header

thanks again guys for your help i appreciate a lot!

By Bryan (66.245.92.143) on Monday, October 04, 2004 - 05:52 am:

One other thing about the head is....the exhaust ports have been made huge. You could probably not get a header big enough (or do you want one that big) to align with the ports. The header should be slightly larger than the ports, not smaller.

By Don (199.2.139.192) on Monday, October 04, 2004 - 05:15 am:

There is no magic part on an engine (well maybe a turbo ) its a combo of parts designed to work together. If even one piece throws the combo off your engine will never be as good as it could be. Allot of people look at peak HP and yes with the hogged out eb3 head you may make a few hp more at peak rpm but on the lower side of the RPM range (the range you spend about 90% of your time in when racing) you will be way way down. If your stuck on using the head then you must match the entire car to it and maybe it would do ok. By that I mean Close ratio box, dual carbs with huge venturis, a custom cam that probably wont idle below 1500 rpm and be prepared to rebuild the engine often as the rpm required to make the ports work is going to be way way up there and a driver that can keep the engine wound up at all times.

By felipe casanova (200.30.216.170) on Sunday, October 03, 2004 - 07:11 pm:

thanks a lot guys, i will put my stock head then, thanks for your help, as soon as i put my head i`ll guys let you know !

and is really that bad if i have put that eb-3 head in my engine?

By Don (199.2.139.182) on Sunday, October 03, 2004 - 04:11 pm:

Yes that will give you the best results with what you have got to work with.

By felipe casanova (200.30.216.170) on Sunday, October 03, 2004 - 01:58 pm:

so i keep my eb-2 then? and i do little porting to mine?

By Don (199.2.139.174) on Sunday, October 03, 2004 - 05:51 am:

With that set up that head will cost you power. Even John who races in GT and shifts at 10,000 RPM advises not to hog out the ports too much.
With your setup you will be much much faster with a properly done eb2 head.

By felipe casanova (200.74.68.39) on Saturday, October 02, 2004 - 07:13 pm:

i will use a 280º cam , mugen header, 4-2-1 exhaust, and stock carb

By Adrian (Evocivic) (203.42.97.141) on Saturday, October 02, 2004 - 05:18 pm:

Looking at those pictures I'd say it's skimmed more than 3mm, and no it won't necessarily make your car fast. The ports look too big and you don't want them polished to mirror smoothness. What sort of cam, carb and exhaust will you be using with it?

By felipe casanova (200.74.68.39) on Saturday, October 02, 2004 - 01:08 pm:

well guys thanks a lot!!! so it`s an Eb-3 head! and yes is skimmed 3mm and with bigger ports and polished like a mirror! my car should be more fast with this head know

by the way i have to use a diferent head gasket right? and anybody know what`s ther diameter of accord pistons?

By Justin (199.60.112.10) on Saturday, October 02, 2004 - 09:56 am:

just a side note.. eb1/2/3 all used a mechanical fuel pump, the el and ek's were electric. and the head you have has a mechanical fuel pump location

By Adrian (Evocivic) (203.42.97.141) on Saturday, October 02, 2004 - 03:14 am:

Looks like and BE3 that's had a lot skimmed off it (probably in the order of 4 or 5mm). It's also had a lot of work done to the ports.

By -Andrew Smit- (Cvcc_Wagon) (154.20.95.104) on Friday, October 01, 2004 - 11:07 pm:

i don't think the accord came with a cross flow head. they had a 1.6l in the first gen's and a 1.8l in the second gen's (usdm) both of those engines were similar to the civic's 1488cc non-cross flow head design

By lazy (165.228.57.19) on Friday, October 01, 2004 - 10:11 pm:

from a previous post:

"Here in canada the EB1 and EB2 heads had a small
S stamped in near were the top motor mount bolts to the head and the EB3 head has a small H"

By felipe casanova (200.74.68.39) on Friday, October 01, 2004 - 09:44 pm:

well guys here`s the deal, today my mechanic get this head from a friend, but we don`t know if this is from a civic(eb3) or an accord? we put the head on my block and fitted perfectly except for the head gasket the gasket left too close of the piston, well here is the thing i wanna know what head it is and what is the size of the accord pistons, oh i forgot the head has an h stamped and mine have an s stamped, well here are the pics my head is the round one, please help me soon i got to race the other weekend!!