porting iron heads w/ dremel = slow.

[notfred]

I think I'll be doing a fairly mild port job. Anyone have a compressor and a die grinder I could borrow?

 

[OneSyberTroop]

haha, oh well man, You'll be happy in the end

Hope all goes well, get your baby up and running.

 

[Zim Hosein]

Originally posted by: notfred
I think I'll be doing a fairly mild port job. Anyone have a compressor and a die grinder I could borrow?

notfred, when you're porting heads w/ "simple" power tools, slow is best

I can't wait to see the PICS when you're done

 

[BreakApart]

Noway.... i borrowed my setup to a friend before and he returned with STRAIGHT ports. The finished heads looked like 10,000 rpm topfuel heads, street performance was destroyed.

 

[notfred]

Originally posted by: BreakApart
Noway.... i borrowed my setup to a friend before and he returned with STRAIGHT ports. The finished heads looked like 10,000 rpm topfuel heads, street performance was destroyed.

He did that with a dremel? That'd take hours per port....

 

[Hayabusa Rider]

Kind of like digging a tunnel with a toothpick, don't you think?

 

[BreakApart]

Originally posted by: notfred

Originally posted by: BreakApart
Noway.... i borrowed my setup to a friend before and he returned with STRAIGHT ports. The finished heads looked like 10,000 rpm topfuel heads, street performance was destroyed.

He did that with a dremel? That'd take hours per port....

No, the original poster is asking to borrow a "compressor and a die grinder". That's what i borrowed a friend, i didn't realize he needed adult supervision. lol...

 

[DaLeroy]

Originally posted by: notfred
I think I'll be doing a fairly mild port job. Anyone have a compressor and a die grinder I could borrow?

I take it you have done this before....not a job to be tackled with no experience.....

 

[Brutuskend]

When I build my engine I spend 10 hours per head porting and polishing and de-shrouding them.

I took them to the machine shop when I was done and had them do three angle grinds on stainless steel valves.

I installed them and got about 500 miles on them before the VALVES SEATS DROPPED OUT!!! ARGHHHHHHHHH (I thought I was getting heads built for over size valves, but it turned out they were new REWORKED heads with the bigger seats installed)

So one set of new factory heads and another 20 hours of porting and polishing and another set of stainless steel valves and another trip to the machine shop and they have been worth the time and money spent...............

These were aluminum heads too by the way, so expect steel heads to take a bit longer...........

ONE TIP I will give you though. Get one of those flex adapters for your dremel. It will make the job MUCH easier.

EDIT: One more tip.

Leave the "Bumps" in the intake ports. They are there for a reason, to make the fuel atomize better....

 

[JC]

What sort of cutter are you using? Even with a Dremel, a carbide burr should cut 'em down pretty quick.

JC

 

[Jerboy]

Originally posted by: BreakApart
Noway.... i borrowed my setup to a friend before and he returned with STRAIGHT ports. The finished heads looked like 10,000 rpm topfuel heads, street performance was destroyed.

I lend my setup to a friend...

I let my friend borrow my setup...

"I borrowed my setup to a friend" doesn't make sense.

Borrow means "To obtain or receive (something) on loan with the promise or understanding of returning it or its equivalent. "-American Heritage Dictionary. That's unless you're talking about borrowing a piece of paper in a class or borrowing some toilet paper from the guy in a stall next to you.

 

[Colt45]

I have a die-grinder and a compressor.. and probably a hundred bits.

you pay shipping both ways

 

[Kadarin]

Heh.. I did mine with an air compressor and a die-grinder.. opened up the bowl areas beneath the valves, and removed casting flash from both intake and exhaust ports. Didn't bother with "polishing"...

 

[MichaelD]

I'm no pro at this...but I know that all the combustion chambers' volumes are supposed to be indentical, else performance probs can result. Hence the terminoligy "Port and Flow the heads."

I have seen this done before. After porting, they turn the heads upside down and place some kind of specialized glass plate over the combustion chamber. Water is then poured in thru a tube that sticks up from the glass. The tube is a graduated cylinder. You're supposed to ensure that the water volumes in each chamber match. IE if chamber #3 holds 2CC's more water, you need to take off a corresponding amount of material for chambers 1,2 & 4.

I'm out of my league here...hope this helps, or alerts you to something...or something....

 

[Colt45]

Originally posted by: MichaelD
I'm no pro at this...but I know that all the combustion chambers' volumes are supposed to be indentical, else performance probs can result. Hence the terminoligy "Port and Flow the heads."

I have seen this done before. After porting, they turn the heads upside down and place some kind of specialized glass plate over the combustion chamber. Water is then poured in thru a tube that sticks up from the glass. The tube is a graduated cylinder. You're supposed to ensure that the water volumes in each chamber match. IE if chamber #3 holds 2CC's more water, you need to take off a corresponding amount of material for chambers 1,2 & 4.

I'm out of my league here...hope this helps, or alerts you to something...or something....

You're thinking of boring, not porting...

err.. wait a second, did you say the chambers are in the head(s) ?

You would not want to bore your chambers with a dremel, thats for sure


maybe i read that wrong.. I've never heard of the glass plate thing though.

 

[MichaelD]

Originally posted by: Colt45

Originally posted by: MichaelD
I'm no pro at this...but I know that all the combustion chambers' volumes are supposed to be indentical, else performance probs can result. Hence the terminoligy "Port and Flow the heads."

I have seen this done before. After porting, they turn the heads upside down and place some kind of specialized glass plate over the combustion chamber. Water is then poured in thru a tube that sticks up from the glass. The tube is a graduated cylinder. You're supposed to ensure that the water volumes in each chamber match. IE if chamber #3 holds 2CC's more water, you need to take off a corresponding amount of material for chambers 1,2 & 4.

I'm out of my league here...hope this helps, or alerts you to something...or something....

You're thinking of boring, not porting...

err.. wait a second, did you say the chambers are in the head(s) ?

You would not want to bore your chambers with a dremel, thats for sure


maybe i read that wrong.. I've never heard of the glass plate thing though.

Yes! The combustion chamber is in the heads. The pistons come up in the block almost flush with the top of the block (Deck Height). The actual compression takes place in the head, when the piston squeezes the air/fuel mixture (compresses) while all valves are closed.

 

[Colt45]

Originally posted by: MichaelD

Originally posted by: Colt45

Originally posted by: MichaelD
I'm no pro at this...but I know that all the combustion chambers' volumes are supposed to be indentical, else performance probs can result. Hence the terminoligy "Port and Flow the heads."

I have seen this done before. After porting, they turn the heads upside down and place some kind of specialized glass plate over the combustion chamber. Water is then poured in thru a tube that sticks up from the glass. The tube is a graduated cylinder. You're supposed to ensure that the water volumes in each chamber match. IE if chamber #3 holds 2CC's more water, you need to take off a corresponding amount of material for chambers 1,2 & 4.

I'm out of my league here...hope this helps, or alerts you to something...or something....

You're thinking of boring, not porting...

err.. wait a second, did you say the chambers are in the head(s) ?

You would not want to bore your chambers with a dremel, thats for sure


maybe i read that wrong.. I've never heard of the glass plate thing though.

Yes! The combustion chamber is in the heads. The pistons come up in the block almost flush with the top of the block (Deck Height). The actual compression takes place in the head, when the piston squeezes the air/fuel mixture (compresses) while all valves are closed.

yeah, i know that.. but i count the whole thing as the chamber. including the portion in the block.

maybe my engine grammar is wrong.. :-/

 

[MichaelD]

The combustion chamber is in the head. <-----Technically, that is correct. In "reality" though, the combustion chamber DOES also encompass the small area within the block itself, b/t the piston top and the head. It is confusing.

 

[Colt45]

ergh.. that just doesnt sound right.

b/c we got the piston as one wall, the block as a wall (during most of the compression), and the head as the endwall/part of the sidewalls..

like.. erm.. compression starts as soon as the piston comes up, and at that time the block covers most of the area.

hmm.. say you have a syringe, with the needle end melted shut.. would the end be considered the chamber, or the entire thing?

 

[Ronstang]

Leave the "Bumps" in the intake ports. They are there for a reason, to make the fuel atomize better....

Uhmmm...this is a port fuel injected car with a blower on it so fuel atomization is not an issue, but there is also no need to make the intake ports a mirror finish....the exhaust ports on the other hand....

 

MichaelD is talking about cc-ing the combustion chamber(s).
Due to manufacturing tolerances,there are variations in the compression ratio from cylinder to cylinder.
CC-ing is nothing but equalizing the combustion chamber volume (Making all the chambers the same).

notfred

I would be extremely careful when porting your cylinder heads,there is a big possibility that you are going to lose low speed port velocity,(Lose low end torque and horsepower).
It takes years of experiance and a flowbench to get decent results.
I have worked at several engine rebuilding facilities during my lifetime and have seen customers come in with home brewed port jobs that would not even idle at 1,500 R.P.M. because of the "Gouged" out ports.
It is best that you read up on the subject first.

 

[Stifko]

I have an exhaust manifold that I'd like to port. The problem is I dunno how to keep the circles round and not oblong or krooked. I thought a dremel tool would be best too, there is only about a 1/2 in to take off all around. It is a cast iron mani.