Engine Cylinders Porting

Hello Gents/Gals
I've been reading about engine cylinders's porting for a while and was wondering if the claims of extra 10 to 20 % more power were actually true?
For everyone here who had the engine cylinders ported, did you noticed or actually get a good amount of extra power and was it worth the price?
Can you also recommend a good shop ( Lycon or anyone else ) to do the work ?

Thanks for your imputs..

Bruno Dionne
[email protected]

The shop that is building up my 540 said that flow balancing to the cylinders, which I think is the same thing as porting, used to be beneficial back in the day when individual cylinders had much more variability. But, with today's tooling and computerized machinery, he said all the cylinders flow the same.

Also, the aparatus he built to flow cylinders was sitting to the side full of dust.

Basically, he said it's not worth it.

Just one opinion...there are definitely other much smarter on this that I am.

-Jim

Talk to Lycon. They have proof of a few HP per cylinder.

Recomend Lycon

I installed some ported & polished Lycon cylinders on a clients engine, very impressed. Russ

fehdxl said:

The shop that is building up my 540 said that flow balancing to the cylinders, which I think is the same thing as porting, used to be beneficial back in the day when individual cylinders had much more variability. But, with today's tooling and computerized machinery, he said all the cylinders flow the same.

Also, the aparatus he built to flow cylinders was sitting to the side full of dust.

Basically, he said it's not worth it.

Just one opinion...there are definitely other much smarter on this that I am.

-Jim

Click to expand...

I have flown my RV-6 O-320 before and after match flowing of the cylinders. What the guy at the engine shop is telling you is TRUE. There was no measurable change in performance or seat of the pants feel.

Here is my Question :

Talking to Aerosport Power, They indicated that they "Flow Match" Cylinders. Meaning they sort cylinders of similar "flow" and then match 4 of them as close as possible for the next engine..

Can this be correct?

If this is the case, then don't you get better flow matching by measuring out more cylinders? What if they only have 10 in the shop to match up.. vs. 100.. They would get much better flow matching with the more cylinders that they have available. I can't imagine that they have tons of cylinders hanging around to match.

Any thoughts?

Flow matching is not the same as porting.

Flow matching may be performed much like injector matching. Just by putting jugs on a flow meter and finding 4 that flow very close to the same amount. This is usually done without making changes to the jugs. I may be wrong but I don't think you can grind on jugs for certified aircraft.

Porting means you are removing metal and generally smoothing the intake and exhaust ports. (more smoothing on the exhaust than the intake) You would then flow match the jugs after you've done your metal removal and polishing so all 4 jugs match in flow.

An internal combustion engine is nothing but an air pump. The easier you make it for the air to get in and out, the more efficient it is.

If the cylinders are ported and polished you end up with larger holes for the air to move through. The polishing part is just to remove any flashing left over from the casting process. This used to be a big issue when the cylinder heads are made from sand castings. Today, most (all?) are made with investment castings and are then machined. Thus, you get smoother runners.

However, if you have enlarged intake and exhaust ports that don?t line up with your intake runners and exhaust manifold, then you can actually end up producing less power. This is more important on the exhaust side as having a lip on the intake can (sometimes) help you.

If you are going to send your cylinders in for this treatment, send your exhaust along with it and have them ?port match? them.

There is an art to porting. Unfortunately not everyone is an artist. Using the best Sable brushes made wont turn your paintings into VanGoghs neither will even the best tools for porting cause your engine to perform better. As I understand it there is a bit of Zen to porting.

Cylinder porting

Hello Gents
Thanks for the info, greatly appreciated.

Sid is correct regarding flow match vs Porting, they are 2 different beast but both improved the engine.

My engine was flow matched and balanced when I overhauled it 2 years ago and it is difinetly smoother now.

What i'm interested in porting is the ''increase'' in horsepower without increasing the pressure on the engine..I read about Lycon and this where I was thinking on sending my jugs if I go this way..Bart Lalonde will be a good choice too ( being in Canada) but I don't know if he 's doing this kind of work..

Keep on sending info, the more the better.

Thanks

Bruno

This is one of those questions that can take days or months to get your head around in the shop, much less in the field. Art form, yes. Do you need to do it? Most offten no. We have been doing this kind of stuff for moany years tring to get more out off our racing carts and birds. Times have changed over the last 50-60 years. We now see more and more injected recips. on the the move. If you run a carb. your fuel and air mix at the intake. If you run injected the fuel and air mix just before the intake valve. You want a very well mixed fuel and air blend to get into the combustion camber. The texter of the inside of the induction system helps if it is a little rough to mix the fuel and air with respect to a carb. recipn. engine. On an injected engine, air flow, smoothling and good vallum to the intake valve is wanted more than mixing. Both engines wil do better with less retricktion, but if you pollish an intake and head port on a carb. engine you may not get a well mixed charge into the combustion camber and do yourself a disfaver. "This can go on for hours." But here is my two cents. Most aircraft heads have very little meat in there castings and taking much out will weakin them. And yes the newer ones made on "C.N.C." cuting lines are very well matched in size and flow.
This is the head now not the induction system we are talking about here.
If you clean just the seams form the casting down and any rough serface, so that the air had no bumps to go over in it trip. You will have done all that it needed on any late modle castings. It takes a very good eye and someone that has been doing this kid of art for a long time. I would not go overbord on this one as your gain is not worth the weakness you may incure here.
Oh we do not polish any more. a good texture of say 120-160 grit will be better to pomote lamminner flow over the suface of the inside of the intake bore. Shiny looks good in the show room, but it slows you down in the field.
There is as I said a lot to this old story. And you can look at this one form a lot of wants and needs. If you are going to race and have big sponsores.
You get to brake a lot of nice stuff. If you are going to run a constent output
engine at a fixed setting for it to last a long time. You get a lot of fun with little brakage. Yours as always. R.E.A. III #80888

Cylinder Porting

Well Gents
Thanks a lot for the info and education, it was really worth it.

I guess I will stick with what I've got for the time being until I can actually see and try the results....


Thanks again

Bruno
[email protected]