Started Porting the Heads on the Chevelle

[94cobra69ss396]

I decided I needed to start working on the Chevelle since it's been sitting for such a long time. I pulled one of the heads and started cleaning up the ports and combustion chambers. I started tearing it apart at about 8 tonight and my wife came out and got me a midnight so I only finished a combustion chamber and exhaust port on one cylinder. I need to get more supplies tomorrow so I can work on it again tomorrow night. I'll also take some pictures of and post them up.

Glenn, do you have access to a flow bench? If so, would you be willing to flow my heads for me? I'd like to finish porting one head and then compare it to the other head before I port it.

[BRUTAL64]

I decided I needed to start working on the Chevelle since it's been sitting for such a long time. I pulled one of the heads and started cleaning up the ports and combustion chambers. I started tearing it apart at about 8 tonight and my wife came out and got me a midnight so I only finished a combustion chamber and exhaust port on one cylinder. I need to get more supplies tomorrow so I can work on it again tomorrow night. I'll also take some pictures of and post them up.

Glenn, do you have access to a flow bench? If so, would you be willing to flow my heads for me? I'd like to finish porting one head and then compare it to the other head before I port it.

Unfortunately, the Flow bench I had access to is gone.

What I found is: if you use a flow bench, all you will do is drive yourself crazy. You'll be there for days. I once spent 3 days on one port.:bang:

[big2bird]

Port, polish, CC them and call it good.;)

[94cobra69ss396]

Unfortunately, the Flow bench I had access to is gone.

What I found is: if you use a flow bench, all you will do is drive yourself crazy. You'll be there for days. I once spent 3 days on one port.:bang:

That's okay. The only changes that I'm making are porting them and then installing new valve springs so I guess I'll see if I did any good when I take it back to the track.

[BRUTAL64]

Port, polish, CC them and call it good.;)

Polish in not really needed. It's a waste of time on a street driven or race engine that is not torn down on a regular basis. A good smoothing of the exhaust ports is all that is really needed. You never want to polish the intake runner of a carb engine. When I do the Port Class for you guys I will explain all that.:judge:

[big2bird]

Polish in not really needed. It's a waste of time on a street driven..........

There ya go, talking about that primer paint job again.............:rolling:

[BRUTAL64]

There ya go, talking about that primer paint job again.............:rolling:

Primer is God's gift to the body challenged.:nuts:

[94cobra69ss396]

Polish in not really needed. It's a waste of time on a street driven or race engine that is not torn down on a regular basis. A good smoothing of the exhaust ports is all that is really needed. You never want to polish the intake runner of a carb engine. When I do the Port Class for you guys I will explain all that.:judge:

I don't polish anything. I do smooth out the combustion chamber though just to get rid of and sharp edges and I unshouding the intake and exhaust valves a little. I'm not doing too much on the intakes because they are already fairly large for this engine. I also know that the rough surface helps keep the fuel atomized and prevents puddling so even if I were to enlarge them I would keep them rough. However, I'm just smoothing the entry on them and blending the short turn radius because they left a little bit of an edge on the intakes. Most of my work is on the exhaust port. I'll take some pictures tonight and post them up.

[BRUTAL64]

I don't polish anything. I do smooth out the combustion chamber though just to get rid of and sharp edges and I unshouding the intake and exhaust valves a little. I'm not doing too much on the intakes because they are already fairly large for this engine. I also know that the rough surface helps keep the fuel atomized and prevents puddling so even if I were to enlarge them I would keep them rough. However, I'm just smoothing the entry on them and blending the short turn radius because they left a little bit of an edge on the intakes. Most of my work is on the exhaust port. I'll take some pictures tonight and post them up.

Actually, you are doing it right from what you wrote. Can't wait to see some pictures.:bigthumbsup::bigthumbsup:

[94cobra69ss396]

Here are some pictures I took tonight before I started working. Since I already did one I took pictures of it and then of one that wasn't done yet. Sorry for the bad pitures but I didn't have very good lighting. As you can see I didn't do much to the intake port besides blend the end of the runner and smooth the short side radius which you can't see all that well. On the combustion chamber I just smoothed it and then unshrouded the sides by both valves. I didn't change the shape at all. The exhaust port is where I spent most of my time. I didn't touch the floor just the roof and walls and I smoothed the short side radius on it too. I also finished the second one tonight so two more to go and then I can pull the other head and start on it.

http://www.motorgen.com/pic/data/500/medium/267.JPG
http://www.motorgen.com/pic/data/500/medium/266.JPG
http://www.motorgen.com/pic/data/500/medium/270.JPG
http://www.motorgen.com/pic/data/500/medium/271.JPG
http://www.motorgen.com/pic/data/500/medium/273.JPG
http://www.motorgen.com/pic/data/500/medium/272.JPG
http://www.motorgen.com/pic/data/500/medium/268.JPG
http://www.motorgen.com/pic/data/500/medium/269.JPG
http://www.motorgen.com/pic/data/500/medium/274.JPG
http://www.motorgen.com/pic/data/500/medium/275.JPG
http://www.motorgen.com/pic/data/500/medium/277.JPG
http://www.motorgen.com/pic/data/500/medium/276.JPG
http://www.motorgen.com/pic/data/500/medium/288.JPG
http://www.motorgen.com/pic/data/500/medium/289.JPG

[heypal]

I have my heads of now lets do port class lol.

[94cobra69ss396]

I have my heads of now lets do port class lol.

I believe Glenn is going to do one. I've actually ported heads before. I ported a set of cast iron SBC and a set of cast iron BBC oval ports. These however are Edelbrock Performer RPM 6055 that I paid $2500 and are aluminum so I don't want to mess them up. The shap of the ports are pretty good as cast and only need a little porting. The aluminum is easier to remove than the cast iron was too so it's going a lot fast. I has taken me about two hours to complete one cylinder. I just hope I do a good enough job to drop 2 tenths or so so that I can get into the 9's.

[BRUTAL64]

I believe Glenn is going to do one. I've actually ported heads before. I ported a set of cast iron SBC and a set of cast iron BBC oval ports. These however are Edelbrock Performer RPM 6055 that I paid $2500 and are aluminum so I don't want to mess them up. The shap of the ports are pretty good as cast and only need a little porting. The aluminum is easier to remove than the cast iron was too so it's going a lot fast. I has taken me about two hours to complete one cylinder. I just hope I do a good enough job to drop 2 tenths or so so that I can get into the 9's.

Yes, the basic design of the ports is very good. What you are doing is going to help. But, becareful here---there is not a lot of room for error. I just don't know if you are going to get 2 tenths with what you are doing. I'd have to see these heads in person. We actually carry the heads here, but don't have any in stock.

If you guys want the porting class, I'm ready anytime. I've talked to Sean and Ben about this. Everyone will learn something worth while.:thumbs_up:

[94cobra69ss396]

Yes, the basic design of the ports is very good. What you are doing is going to help. But, becareful here---there is not a lot of room for error. I just don't know if you are going to get 2 tenths with what you are doing. I'd have to see these heads in person. We actually carry the heads here, but don't have any in stock.

If you guys want the porting class, I'm ready anytime. I've talked to Sean and Ben about this. Everyone will learn something worth while.:thumbs_up:

I know it's hard to tell from the pictures but here are what I did. You can also see larger images if you go to my photo album.


In this picture I circled the area where I widened the runner. I only did the roof and walls.
http://www.motorgen.com/pic/data/500/medium/268EW.jpg

I also took some metal off of this area as you can see in the next 3.
http://www.motorgen.com/pic/data/500/medium/268EN.jpg

If you compare this one to the stock one below you can see how I reshaped it to enlarge it a little.
http://www.motorgen.com/pic/data/500/medium/268ESW.jpg

The stock port.
http://www.motorgen.com/pic/data/500/medium/269ESW.jpg

If you look at the sides of the combustion chambers you can see where I unshrouded them a little.
http://www.motorgen.com/pic/data/500/medium/273W.jpg

Stock.
http://www.motorgen.com/pic/data/500/medium/272.JPG

Here you can see that I removed a little from the short side on the intake.
http://www.motorgen.com/pic/data/500/medium/270IS.jpg

Stock.
http://www.motorgen.com/pic/data/500/medium/271.JPG

Here is where I smoothed the intake runner. I only went in about an inch and consentrated on the roof and walls.
http://www.motorgen.com/pic/data/500/medium/288W.jpg

Stock.
http://www.motorgen.com/pic/data/500/medium/289.JPG

[BRUTAL64]

I know it's hard to tell from the pictures but here are what I did. You can also see larger images if you go to my photo album.


In this picture I circled the area where I widened the runner. I only did the roof and walls.
http://www.motorgen.com/pic/data/500/medium/268EW.jpg

I also took some metal off of this area as you can see in the next 3.
http://www.motorgen.com/pic/data/500/medium/268EN.jpg

If you compare this one to the stock one below you can see how I reshaped it to enlarge it a little.
http://www.motorgen.com/pic/data/500/medium/268ESW.jpg

The stock port.
http://www.motorgen.com/pic/data/500/medium/269ESW.jpg

If you look at the sides of the combustion chambers you can see where I unshrouded them a little.
http://www.motorgen.com/pic/data/500/medium/273W.jpg

Stock.
http://www.motorgen.com/pic/data/500/medium/272.JPG

Here you can see that I removed a little from the short side on the intake.
http://www.motorgen.com/pic/data/500/medium/270IS.jpg

Stock.
http://www.motorgen.com/pic/data/500/medium/271.JPG

Here is where I smoothed the intake runner. I only went in about an inch and consentrated on the roof and walls.
http://www.motorgen.com/pic/data/500/medium/288W.jpg

Stock.
http://www.motorgen.com/pic/data/500/medium/289.JPG

You are doing some good here. It's just the ports are pretty good already. You might want to shorten the valve guide a little also, but not too much.

Just a little side note here; I (myself) like to have the runners/port on the intake about 1/16 to 1/32 larger than the port/runners on the intake. Right where the two come together. I really helps with back pulse.


We need to do the porting class soon.

[94cobra69ss396]

You are doing some good here. It's just the ports are pretty good already. You might want to shorten the valve guide a little also, but not too much.

Just a little side note here; I (myself) like to have the runners/port on the intake about 1/16 to 1/32 larger than the port/runners on the intake. Right where the two come together. I really helps with back pulse.


We need to do the porting class soon.


I haven't checked the ports on the intake manifold yet but I'm going to when I'm done with the heads. I'm running a Victor Jr and if I remember correctly from when I installed it they were just about the same size as the ports on the heads.

[big2bird]

Polish in not really needed. It's a waste of time on a street driven or race engine that is not torn down on a regular basis. A good smoothing of the exhaust ports is all that is really needed. You never want to polish the intake runner of a carb engine. When I do the Port Class for you guys I will explain all that.:judge:

Come on Glen. You can polish both, then use a flapper to give the intakes a "satin finish." Same thing. :pot_stir:

[BRUTAL64]

Come on Glen. You can polish both, then use a flapper to give the intakes a "satin finish." Same thing. :pot_stir:

Sure, what ever you say.:thumbs_up:

[big2bird]

Sure, what ever you say.:thumbs_up:

:nutkick::nutkick::nutkick:

[BRUTAL64]

:nutkick::nutkick::nutkick:

That hurt.:(

[94cobra69ss396]

So I finished porting the heads on Saturday. Then on Sunday I cleaned the valves, lapped them and then installed the new valve springs. Here are some pictures of the completed work.

Glenn, I didn't shorten the valve guide because they are not very long and I was worried about how stable the large valve would be with the high spring pressures. I didn't want to compromise the stability of the valve and felt that the little bit of added cfm, if any, was worth the chance of the valve being able to rock in the seat. I'd rather have them last a long time.

Exhaust.
http://www.motorgen.com/pic/data/500/medium/100_0915.JPG
http://www.motorgen.com/pic/data/500/medium/100_0919.JPG
http://www.motorgen.com/pic/data/500/medium/100_0921.JPG
http://www.motorgen.com/pic/data/500/medium/100_0922.JPG
http://www.motorgen.com/pic/data/500/medium/100_0923.JPG
http://www.motorgen.com/pic/data/500/medium/100_0924.JPG
http://www.motorgen.com/pic/data/500/medium/100_0925.JPG
http://www.motorgen.com/pic/data/500/medium/100_0926.JPG

Seat before lapping.
http://www.motorgen.com/pic/data/500/medium/100_0927.JPG

Seat after lapping.
http://www.motorgen.com/pic/data/500/medium/100_0933.JPG

Cleaned valves.
http://www.motorgen.com/pic/data/500/medium/100_0928.JPG

Before lapping.
http://www.motorgen.com/pic/data/500/medium/100_0929.JPG

After lapping.
http://www.motorgen.com/pic/data/500/medium/100_0935.JPG

Intake.
http://www.motorgen.com/pic/data/500/medium/100_0920.JPG

Combustion chamber.
http://www.motorgen.com/pic/data/500/medium/100_0918.JPG

New springs.
http://www.motorgen.com/pic/data/500/medium/100_0936.JPG

During install.
http://www.motorgen.com/pic/data/500/medium/100_0937.JPG

[BRUTAL64]

Only comment--your intake port needs to be a little bigger (.060 or so ) than your intake port. This helps revision. You are on the right track, just need to to clean up the outer intake port at the gasket (leave port rough).

The exhaust port looks OK, but could use a little clean up- the smoother it is the less carbon build up. Other wise a very nice job. :thumbs_up:

[Vettezuki]

. . . your intake port needs to be a little bigger (.060 or so ) than your intake port. . . .

Uhhh . . .

[94cobra69ss396]

Uhhh . . .

Intake port on head vs. on intake manifold. Make the intake on the head larger than the intake on the intake manifold.

[Vettezuki]

Intake port on head vs. on intake manifold. Make the intake on the head larger than the intake on the intake manifold.

So you want the air/fuel mix to slow down and very slightly cool as it enters the head? Is there some other objective?

[BRUTAL64]

So you want the air/fuel mix to slow down and very slightly cool as it enters the head? Is there some other objective?

Other objectives. See, I keep telling you, a head porting class.

The difference has more to do with reversion and port alignment.:drink:

[enkeivette]

Intake port on head vs. on intake manifold. Make the intake on the head larger than the intake on the intake manifold.

I left my intake about a 1/16 smaller than my head port, all the way around.

Nice work! :beer:

[big2bird]

My only comment on this is the valve head/seat contact area. Last time I did a a valve job, a LONG time ago, when 3 angle seats were fairly new, it was desired to make the contact area as small as possible. Your lapped area looks rather large to me. Has the thinking been revised?

[94cobra69ss396]

These heads are only two years old and I haven't had a valve job done on them. The angles are what Edelbrock used. The heads are Performer RPM rectangular ports and the seats have 3 angles and the valves have one. I'm sure there is more power in a good multi angle valve job but I don't have the cash to spend on it right now and the valves and seats are in good shape so I just lapped them.

[BRUTAL64]

These heads are only two years old and I haven't had a valve job done on them. The angles are what Edelbrock used. The heads are Performer RPM rectangular ports and the seats have 3 angles and the valves have one. I'm sure there is more power in a good multi angle valve job but I don't have the cash to spend on it right now and the valves and seats are in good shape so I just lapped them.


A 30 degree back cut on a exhaust valve helps the low lift flow. If you going for every little bit of horse power this will help. If not leave it alone. If you have Manley valves, if I remember our conversation correctly, then they should already have all the correct valve angles. I've done SIX angle cuts on my own heads when I had all the gear. But, that's just over kill.:p

[94cobra69ss396]

A 30 degree back cut on a exhaust valve helps the low lift flow. If you going for every little bit of horse power this will help. If not leave it alone. If you have Manley valves, if I remember our conversation correctly, then they should already have all the correct valve angles. I've done SIX angle cuts on my own heads when I had all the gear. But, that's just over kill.:p

I'm not sure what make the valves are. They're whatever came on the heads from Edelbrock. The valves only have one cut on them, not two, so they must not be Manleys.

[94cobra69ss396]

I worked on the car last night for a couple hours and I got the heads on, installed and adjusted the rockers and installed the intake. Tonight I'll install the distributor, plugs and wires and it'll be ready to fire.

[BADDASSC6]

Talking about porting and polishing. Do you guys have a recommended shop in Socal to port match my FAST intake maniforld and port my throttle body? I am basicly getting ready to do the next batch of mods to the vette trying to have her ready by October 1st.

[94cobra69ss396]

Talking about porting and polishing. Do you guys have a recommended shop in Socal to port match my FAST intake maniforld and port my throttle body? I am basicly getting ready to do the next batch of mods to the vette trying to have her ready by October 1st.

Why not port it yourself? Just in case you don't want to I have a call into Throttle Crazy. His buddy owns a shop that specializes in LS motors. Mostly for sand rails. The last rail he built for himself had a twin turbo LS in it and it made over 1400rwhp. I'll see if he does porting and let you know.

[94cobra69ss396]

Why not port it yourself? Just in case you don't want to I have a call into Throttle Crazy. His buddy owns a shop that specializes in LS motors. Mostly for sand rails. The last rail he built for himself had a twin turbo LS in it and it made over 1400rwhp. I'll see if he does porting and let you know.

Carlos, I spoke to Throttle Crazy and his buddy sends heads an intakes out to be ported. He uses a place in L.A. Throttle Crazy recommended using Speed-O-Motive if you don't want to do it yourself.

[94cobra69ss396]

The Chevelle is back up and running again. I took it for a short drive this morning and the rockers were a little noisy so I let it cool down this afternoon and then re-adjusted the valves tonight.

When I first put it together a couple years ago I ran it on a chassis dyno to check the AFR and it made peak hp at 6300. Before I pulled it apart to do the porting I was having to shift at 6000 rpms because it would run flat any higher from valve float. The springs were getting weak.

Well, it pulls strong again. I jumped on it once in second and quickly shifted it to third at 6800 because it just lit up the tires but at least it pulled strong and didn't float the valves. I jumped on it once in third as well and it started to break the tires loose again so I got out of it. I need to throw my slicks on and give it a quick second gear pull to see if it will pull strong to 6500 where I use to shift at.

I can't wait until October 31! :nana2:

[Leedom]

Other objectives. See, I keep telling you, a head porting class

Stop talking about it and lets do it!:sm_laughing:

[Vettezuki]

Stop talking about it and lets do it!:sm_laughing:

It's not his fault. I haven't put it together. I'd like to actually record/document it for the benefit of mankind to infinity and beyond.

[BADDASSC6]

Speed o motive. Sounds good to me. Do they need the head too. How iwll they match them w/o it? Gaskets?