Well the time has come to pull the heads and do a mild port & polish with a port & polish kit. I am planning to use a Impala SS head gasket to kick the compression up a few notches closer to 11:1. I dont have to worry about the pushrods do I? I want to switch to 1.6 roller rockers as well (the stock size stud is 3/8??? I think). These are usually set to zero lash correct?
Anything else I should look out for? This will be my first time pulling heads but I have a buddy helping me.
Thanks for your help as always

 

When pocket porting & working a set of Vette heads the most important thing is to remove material only where it will increase flow the most, while maintaining or enhancing chamber swirl. You will also likely want to work the chamber a little to smooth the spark plug boss and unshroud the intake valve. I STRONGLY recommend Daivd Vizard's book "How to Build Max Performance Chevy SBs on a Budget", available from Amazon.

Depending on how much you reduce the quench height you may need shorter pushrods. You may need an adjustable push rod to determine best length.

I believe your stock studs, like those in the L98, have 7/16" screw base with 3/8" top. Since you will likely be pulling the studs anyway just upgrade to ARP 7/16" studs and get a set of CC ProMag RRs to match.

I look forward to the chance to pull my heads and port them; I've had the intake base & valve covers off and was sooo tempted to just pull the heads and do it.

Have fun with a great project.
How much do you

 

Porting and polishing your own heads. First off, clean the carbon off of them, it will make things much easier. Most machine shops can tank them for really cheap and they'll look brand new.

Gasket match the intake ports. Don't go in further than an inch or even less. You'll want to progressively get less deep as you go in. If you cut into the pushrod spaces, you'll be looking at costly repairs or new heads. Leave the area somewhat rough also, you don't want a completely polished surfeace on the intake ports because the rough surface will help keep the fuel atomized. Next you can narrow the valve guide bosses. This can take considerable time with the sand rolls. Don't cut into the guides, but you can take a lot off material off there. Next, clean up an extremely rough spots and casting flaws all along the intake tract. Raise the roof of the bowl area a little and in general, smooth that area up. The cleaner in the bowl, the better. Finally, install the old valves and clean up the combustion chamber, polish this to the best of your ability. Sharp edges=bad=detonation.

As to the exhuast it is pretty much the same except, do not gasket match them or you'll be asking for exhaust leaks on all the cylinders. Also, the exhaust can be polished completely unlike the intake. Again, the roof area(top) is where you'll want to spend most of your time.

Stay away from the short-side radius unless you have someone with experience to show you what to do.

Take your time, and it will come out great. Also, I recommend switching the valves to 2.00" and 1.56" valves from Ferrera. Which can be bought for cheap from http://www.sdpc2000.com They don't list the sizes on their web site so you'll have to call to get them. I think the total was $180 for the 16 valves and shipping. Combine that with a 3 or 5 angle valve job from a machine shop(~$100) and you will have awesome flowing heads.

I miss anything.

 

Thanks for the great info guys!!

 

I would leave that job to a PRO.

 

Another option is to buy some used heads off of eBay or something and port those just in case something happens.

 

I second 65Z06's recommendation. Read Mr Vizard, and you will see the light. For that matter, read all of Mr Vizards books.

You may wish to get some unservicable heads from a salvage yard, buy a few tools, view a good video, and dive in. I would practice a little on some e junked heads.

Hope all goes well.

dlmeyers 90 coupe zf6 3 speed shocks

 

yup, i agree. or practice on another set of ford mustang heads this is something that can be really screwed up quick if you don't know exactly what you're doing.

 

I cant answer any porting questions but I can tell you That I used the stock pushrods with the impala gaskets and I had the heads milled .030. This was with the hotcam kit. So IMO the pushrods should be ok. Lash was set at zero and then an additional 1/4 turn.

 

I think I can handle gasket matching the intake side and just touching up and polishing the exhaust side without too much trouble. A buddy of mine said to replace the pushrods and lifters while Im in there. Is this a good idea or are they just fine at 68k miles?
Thanks again

 

 

It's really not that hard guys. Ever tried it? Just don't go too crazy and check your thicknesses regulary. If you're getting close, you're probably cutting off too much anyways. If you want a race port and polish, leave it to the pros, but don't pay $800 for someone else to do what you could have done for $200.

I hate paying money to any mechanics, they're all scammers, I swear.

 

Here, here now! Not ALL of us.... Really though, like he says, it's not that hard. Just do your research first.

 

skydaman, you realy need Vizard's book because the added power isn't in gasket matching and polishing, tough it looks nice these net almost no power gain. Rather it's in dressing the valve bosses, blending the seat into the bowl and a little shaping of the bowl, in the right places. Of course you do want to remove any casting flashing from within the head runners but to not remove excessive material. Even taking material off the wall opposite the pushrod boss won't net much gain compared to careful work in the bowl area.

When you do the heads, have the guides replaced, get a 5-angle valve job, go to 2.00"/1.56" performance valves and put some $$ into the valve train. I would install hardened pushrods & guides with RRs and 7/16" studs but would not replace the lifters though. Then you will use the old valves when grinding/polishing in the chambers. Also you should get a kit so you can CC each chamber before you start on them. That way you can partially blue-print the engine while in there.

I think it will be a great project and net you much satisfaction along with a good power gain. Gees, now you have me wishing I had the facilities to do mine.

 

Going to Barnes & Noble to look for this book!! I have time to read up as Im not tackling this project for another 2 weeks.
Does anyone know a good roller rocker that fits on the stock stud? Do the Crane Gold?
Thanks

 

Crane will fit but consider Comp Cams ProMagnums (available for either 3/8" or 7/16" studs) as they have less rotating mass and are stronger. You can order these direct from Comp Cams for quick delivery and good pricing.

 

I have heard good things about the pro magnum, what size should I order for stock studs? 3/8" or 7/16" Or like stated above should I order new studs as the base is 7/16 and the top is 3/8
Thanks


[Modified by skydaman, 3:05 PM 6/25/2004]

 

Anyone have that book that can Scan some of the good pages of Porting 113 heads.

 

I would (and have) gone to 7/16" ARP studs; they only cost around $30 from Summit.

This is no big job as you need to remove the stock non hardened guide plates anyway.

Sorry but I don't have a scanner and there are quite a few pages on head porting and a lot more info in there.

 

See the story regarding having my heads ported. My signature has a link to my website.

Basically, the decision is cost. I got all the work done on my heads by a real professional for $500. Granted, they were LT4 heads and got pocket porting and retained the original valves. But when getting your heads ported, you should get a 3 or 5 angle valve grind which you can only get at a professional shop with the right equipment. Many of the prices you see for porting includes parts such as new valves, guides, & seals. So the cost of the real porting may not that much.

Yes, anyone with a grinder can "port" a head. But in my opinion, the cost to have professional do this type work is money well spent.

As for the comment all mechanics are scammers, I would have to disagree. The do seem to charge a lot but they have to pay salaries and rent, so it cost money to stay in business. Over the past 30 years, I have restored a number of cars from the ground up and do most of my own maintenance work. But when it comes to things that require unique skills or tools, I gladly leave that to a professional.