Well I have some pictures from this set of ported swirl ports that are in progress. I have about 2 hrs into this head so far. The other is still more or less untouched. I have already finished the exhaust ports but still need to do the bowls on 3 cylinders. I have also worked with the intake ports but need to do the bowls on 3 cylinders. The intakes need some more work. The casting flash is going to be filed down where the port narrows into the swirl ramp. Most castings have terrible casting flash there. Get rid of it and you will see huge improvements in flow. The swirl ramp in the one cylinder has been ground down and reshaped somewhat. The pocket underneath it has been enlarged. Notice closely in the closeup of the chamber, the "LIP" that sticks out about 1/2" below the valve seat has been ground smooth and flat. The valves have been unshrouded a little in 2 chambers and the tooling lug smoothed out and reduced in size. The chamber has been lightly polished in the same two chambers. I am using a good valve spring on these, along with a good valve stem seal, and I am doing a 3 angle valve job in the garage.

The pictures that I have kinda suck, no light and the flash was coming back off the port work. Hopefully it will be sunny between now and Sunday when I put them on.

















This is for those who will absolutely avoid the swirl ports. Go buy you some angle plug aftermarket heads. These are dart iron eagle 230 CCs with a stock Carb/TBI van style manifold.

 

Fast,

Do you have any addition picks of the chamber and swirl ramp. I hate to ask you this but can you retake some of those in hopes of clearing them up? Since you are skilled with port work on SP heads I want to use your pics for reference on my 187 head project.

 

Lookin good!

I just started on my 601's last night. They have 1.94 valves and screw in studs. I planed on spending 45 min per cyl to do a quick cleanup and ended up spending 2 hours on one cyl. Carbide burs ROCK!!! I was able to really move some material fast. I gasket matched the ports widened the pushrod pinch as much as possible left the area between the pushrod pinch and pocket alone and then necked down the valve guide boss into a nice airfoil shape. I can get the closed end of an 11/16's wrench throught the pushrod slot, and I can get my 1/2" bur between the valve boss and the narrow side of the port. The wide side is probably close to 5/8". When I started I couldn't even get my 3/8" bit in the narrow side of the guide. My main goal was to try to keep velocity constant and slowly neck down to the valve without any un-needed disruptions. I also unshrouded the valve, when I started the intake was completely blocked around 30% of the valve. I've got 3/16" clearnace now and blened the seats while I was at it. I may try to find a flow bench to test these babies out if it's not too far of a drive.

How wide are the ports on your heads? I'd like to get an idea of how much the port tapers down as it goes to the valves.

 

Perhaps someone could answer the following for me:
(I pose this hear because they are pertinent to this head)

Has anyone put larger exhaust valves into a 193 casting? I understand the factory induction hardened seat may be an issue and a false seat may be required to accomodate the larger valve. This may have reliability issues later on.

If the flow data are correct and the exhaust side is limiting the 193 casting then a larger exhaust valve and better exhaust manifold may go along way to improving the flow without a very aggressive port job(don't want to strike water).

How much chip tuning is required to match up the TBI to the ported heads?

(General question)
My civi L05 is in a Caprice( large/heavy vehicle) so the high RPM flow numbers will not ever be seen. Is there any particular improvements in the cam/intake/head/exhaust that will improve low end Hp and torque up to 3500RPM?

Does anyone know a good place to find 193 castings in LA/OC area?

Thank you

Scott

 

yes you can put bigger ex. vavles in, and yes you need to put seats in it as well. i did them on my 193 heads.

i work in a engine machine shop, and i do valve jobs to get myself through college. its not a terribly hard thing for a set up shop to do. i can do a set of smallblock heads in about an hour and a half. that is just the time it takes to cut for seats, install the seats, cut the seats, and stone the seats to the right thickness.

GM's hardening on the 193s was pretty bad, but you guys should see how bad it sucked on the Furd heads from the same era. at least on the GM heads you have like .030" to play with before putting in a new seat. on the fords i just put seats in them, its no use even seeing if they are still hard.

 

What effect does the larger valve have on breathing/low end power? What change did you notice?
Do the new seats compromise reliability?
Did you put in screw in studs at the same time for higher cam lift?

How happy were you with the improvement versus the time/money invested?

Thank you for your response.


Scott

 

the new seats increase reliabliltiy. they are steel, and the stock seats are "hardened" cast iron. the seats we use are incredibly hard. they dominate the stock hardening.

i can't really say how they affected anything because i did everything in one shot, then swapped the LO5 for the 383. so i can't say how much it helped. i think they do increase low end a bit though, because that is what my engine is build around, because it is always moving a 6000 lb brick around.

no i didn't put screw in studs in. i did macine the guide bosses to handle more lift though, and i have a positive type seal on all 16 valves.

i'm happy with the power it makes, but there is aways room for improvement.

 

Would you do anything differently if you had to do it again?
I must keep the 350 so a 383 is out of the question.

Thank you

 

i would've put a bigger cam, and maybe put some aftermarket heads on it. (which i might do in the future) but all in all, the tbi 383 is a hell of a motor.

sorry to jack ur thread fast.

 

are you doing this job yourself? what kind of tools are you using?

 

if you're referring to me, i do the heads in an engine shop, so i have all the tools necessary to do the work.

 

details on how you are doing this please


Maybe im all wrong but i had an idea to make a jog to hold the valve and rotate it with a flex drive and hand drill across a belt sander(laugh laugh) or grinding wheel at various preset angles.

however a while back I grabbed an old motorcycle valve outta a engine i was melting and chucked it up in my flea market drill press and made a tool post for the tail of my file, it made some descent cuts but I know that axial load is hell on the bearings of that lil junker drill tossed around if that would be feasible enough to do 16 valves accurately or not.

 

A 3 angle valve job really means that the valve seat is cut for three different stepped angles, so that the airflow can (somewhat) smoothly transition from flow in the bowl to flow past the valve. The valve itself only makes contact on 1 of the 3 cuts.

So you can use a drill/stone to work the valves themselves if you are careful not to mess with the contact face of the valve, but you can't easily use a drill to cut valve seats on a head. HTH.

 

actually figured both were cut angled to seat better, i guess i was trying to say is to backcut the valves as well, like this


ganked off google link

 

we do backcutting on performance builds. for everyday stuff, we usually don't, but for the guys looking to get every bit out of their engines, we do them.