Got round to doing more work on the heads. I have removed the portion of the valve guide that prodtrudes into the port, and straightened the port around it as best I could with the tools available.

The tools as it happens were a mill with ball nosed cutter for removing the bulk of the material. Followed by a die grinder with poor HSS cutters, which I sharpened periodically with a dremmel (quite surprised at the success of that actually). I finished up with the dremel as I used hte compressor at my folks place.

I need to perfect getting decent pictures of the ports, I'm there now, so will retake some pictures after doing some more tomorrow (on the other head).

But now some pics!

Standard inlet port.

 

Looks good. Is this a trial and error type thing, or did you flow test before or have advice? I also have a spare set of heads to go on my ej25 bottom end now - trying to decide how much to play

I'm getting an inlet manifold flow-matched (per tract) plus a slightly larger throttle body. Can't decide whether to just port match the heads, or go further?

Richard

 

A lot of it was based on the pics that SMG posted. The main areas were remove casting flaws, increase throat size, remove valve guide, knife edge divider and generally try and keep the ratios of port area similar, ie slightly smaller as you get towards the throat.

I might get them flow tested when they go for some other work, just to compare with the known good results that SMG has.

Exhaust port harder as the shape restricts access, but I have done those too.

Paul

 

replied on 22b.

 

Looking good
Steve.

 

better pictures on 22b where I intend to cover most of my stuff from now on.

I'm doing most with a dremel, which isn't as bad as it sounds. I think the ideal tools would be a 25mm sanding drum on a 4-5" spindle, and a 20-25mm flapper wheel of the same.

I was on the verge of getting a compressor, but for £50 I can get a router, £60 buys a bosch router, both of which are 500w motors that you can take out of the router frame, they have a 1/4" chuck so will take standard TCT cutters. 'ROTOZIP' is similar with added 3 speed control but closer to £100.

£180 elec die grinder has good reach, but it's all money, and I don't make a living out of it.

Paul

 

What sort of RPM is that pumpin out? I remember reading an article in CCC about porting but recond without a proper peice of kit it would take ages.

What sort of benifits have you (measurably?) achieved from doing it?

 

The dremel (actually a black and decker) runs at 33000 rpm.

My die grinder is about 24000rpm@80psi from memory. It goes mental at 200psi though!

The dremel and sanding drums remove a surprising amount of material, remember it's largely alumnium though. For grinding back the valve seats I used a Tungsten Carbide cutter, which was quite aggressive. For removing most of the valve seats I used a ball nosed cutter in a milling machine, which can remove plenty'O'material very easy.

Paul

 

Very nice. It would be good to see before and after CFM readings though.

My only concern is that knife edge, too sharp and it may become prone to cracking and breaking away.....

F

 

knife edge is on the inlet, so I don't think it will be a problem, not at the 60degrees or so the inlet sees, especially as the fuel injector is pointing straight at it. Besides it's not as sharp as it looks, which isn't much different from standard to be honest.

Exhaust is different perhaps, and i haven't gone as far, mainly because I can't reach with my current tools.

I do intend to get some flow tests done, and then I can compare to known numbers from a professional job. I figure any gain is worth it, and it hasn't taken lots of time, besides which I enjoy doing it (to a point).

Worth pointing out I haven't take the ports much bigger at all. There looked to be quite a restriction in the valve seats and valve guide areas. I want to start working on the inlet manifold next, not that i will be able to do a huge amount unless I cut it open and reweld it. Another option is a Fabricated tubular manifold like the slightly older WRC cars.

Bored out throttle body with new butterfly next.

Many a miggle makes a muggle...

Paul