Just a curious question. Why is it a lot of people on here are more likely to spend +$1000 on heads, rather than spend $35 on a Standard Abrassive's kit and pocket port their stock heads?

I know that the Vortec heads are cheap, but even after all the money is spent to make them fully compatible on a car that has an EGR, and a cam with more than .470" lift, or need to keep the 58cc chamber size, it's gonna cost damn near $1000, if not more.

I dunno. I guess it is physically easier to just buy a set of heads and flop them on. And you will probably gain 40+HP over stock.

But pocket porting has been shown (many times) to give a 25-30HP gain. Even having a machine shop that specializes in hi-po mods do it, will cost ~$150 for both heads. Add that to a valve job, and swapping the guides if needed (~$200 for both jobs on both heads) you've still only spent ~$350.

And anyone can gasket match. That's easy. You just have to follow a few lines, blend it nicely, and don't start hoggin' out the runner, etc.

Why will people spend ~$250-300 on a cat back exhaust system to gain 10-15HP (on a good day ), but won't spend $300-400 (or much less if the you do the porting) on stock heads to get them pocket ported and rebuilt to gain at least 20-25HP?

AJ

 

There's more to heads than the flow. But, pocket porting will help most any head, factory or aftermarket, that isn't CNC ported. The SA guidelines are good for either, and the power output will be more if done to an aftermarket head than to a factory head.

Aftermarket typically have screw-in rocker studs vs. press-in for factory (except aluminum) as well. Better castings, more meat where it's needed, etc., etc., etc.

 

If using the SA guidelines, can the porting be done by a first time porter (like me). Can you use a Dremmel to pocket port?

Mark

 

Oh yea. I forgot the 90% of the people on this board use their cars strictly for racing, not going to work, or cruising with friends, or going school.

Come on!!!!!! How many heads have you cracked by driving your car like you do now?

You got a good point with the fact that they're "stronger" and they have screw in studs. But how much is the thicker deck really needed on the street? Yea the screw in studs are needed past a certain spring rate. But you can also have that done. Or buy the $20 tool and do it yourself.

Seems like everyone wants to spend, spend, spend, but nobody wants to do any labor to get what they want. They'd rather just spend the money.

And I know that aftermarket heads, that aren't CNC-ed, also benefit from pocket porting. But they're so well designed, how much do you really think pocket porting helps them?

I guess I'm too old fashioned. I'd rather take pride in doing the mods myself rather than flashing my wallet and just slapping parts on. That and I'm a penny pichin' son a b!tch.

Don't get me wrong. I think the aftermarket heads that are available today are 10 times better than what they were 15 yrs ago when I started driving. And not much more expensive. But I learned to make do with what I had. So I guess that's just the way I am.

 

To answer your question of why go to aftermarket heads...

Porting heads is a very involved process. If you want to make any real gains you can expect to spend A LOT of time slaving over them with a grinder. This is dirty, noisy and yet you have to be careful work. And in the end you still won't get anywhere near what any decent aftermarket head will give you. And it's not just the cost of a SA porting kit. You still need a valvejob, springs, etc. You will need more than just the SA porting kit to get really good gains as well. Don't forget that a lot of people (well over 90% of this board ) do not have a compressor and die grinder, or a suitable place to spend a few weeks in their spare time grinding away without annoying their neighbors into calling the cops for noise ordinances, etc.
And in the end you will have dumped some amount of money into stock heads that you could have used to buy something better out of the box that didn't involve any trouble. This isn't a cop-out, it's simply not wasting money on something that you know will be your weak link.
There's nothing wrong with taking the budget approach and doing some clean-up on your stock heads if your goals aren't that high. If you're sure you don't need much better than mid 13s ever, then certainly it's worthwhile to stick with stock.
If you're trying to go fast, speed costs. And in the case of reworking stock heads vs. aftermarket, it's no contest. You will be faster with aftermarket heads, and if you don't waste money on the stockers early in the game, you'll be that much ahead.

 

Yes you can do it. But a dremmel won't work with the SA kit because the kit needs a 1/4" collet. But you can buy a electric die grinder from (click here--->) Hargor Freight for about $40.

I would call a local machine shop and see if they have any cracked heads laying around. Tell them you wanna use it for practice. They'll usually give them away if they're cracked.

Just remember to keep the pocket smaller than 90% of the intake valve (85% is safer), and no smaller than 85% on the exhaust side. (Example: 1.94" x 90% = 1.746") <---- DO NOT GO BIGGER THAN THAT!!! Actually 85% (1.649") will do nearly as well, and you won't run as high of a risk.

Then just blend the transition between the seat and the valve nice and smooth. And do some light (very light) grinding on any ridges or humps left in the runners by the cast mold.

Just don't over grind. You don't wanna get the "more is better" thinking. You will do more harm than good. K.I.S.S. Oh, and stay away from the valve seats where the valve sits. You don't wanna nick one up, or grind through it. Just stay on the under side of the seats and you'll be fine.

Good luck in your venture, if you proceed to try it.

AJ

 

I am trying to port my TPI Irons with a Dremmel and it isn't working out. You really need a high speed grinder to really cut. Do your meat and potatoes with high speed grinder, and then finish it off with the dremel, if at all possible.

-

As for the stockers, there are certain inadaquacies that a stock head will never overcome. Have you ever stuck your finger down the runner of an L98? There is a big gauge for the rocker stud! That can help flow. As well as a poor combustion chamber, until you get into the 90's, but LT4 heads cool in reverse, and LS1 heads seperate the exhaust runners. So Vortechs are the only awnser, as an alternative. But by the time you hog out a Vortech, you could have boughten a Fast Burn. Quite the paradox!

This doesn't mean that you dont want to port a stocker or buy some Vortechs. You have to pick your performace level and plan accordingly.

BTW Do Vortechs and Fastburns share the same bolt pattern?

 

I did my first head porting job over christmas break. I question the $150 figure for professional porting, that was quoted above.. Now that I see how many hours a porting job takes, I know why people don't just automatically get it down whenever they get an engone rebuilt! It is VERY time-consuming and labor intensive. Granted, a pro would do it in half the time I took (or less) but I figure I put about 30 hours into it so its still gonna end up being several hundred dollars.

I bought the SA kit, but I did most of the metal removal with a carbide NF burr. (the heads were aluminum L98s) The stones and sandpaper cartridges seemed better for smoothing out rough edges and stuff, so that's what I saved them for. the "cross-buff" pads worked good, but there just wasn't enough of them to do a really good polishing job. If/when I do another set of heads, I'll be buying more cross-buffs!

And as far as doing it in your basement or something.. I advise against it if you live with a female and plan on getting any this year! It is a noisy, dirty job, and like I said you're gonna be doing it for many, many hours. I'm lucky because I work in a stamping plant that was shut down for a couple weeks for the holidays.. I had plenty of peace and quiet to work on the heads, and nobody was around to complain about the mess or the noise! Oh, and give up the idea of using a dremel. even if you got enough 1/8" bits to do it, the dremel tool just doesn't have enough ba**s to do a job like this.


Anyway, the best thing (to me) about doing your own port/polish job is you can say to yourself (or others if you like to brag! ) that YOU did it. It was a good learning experience, and hopefully i'll get a couple extra HP out of it!

 

When I first decided to build a new engine for the Z, a friend that had connections at a GM dealer told me he could get his hands on 2 350's, a 98, and a 91. The 98 had Vortecs on it, but both needed rebuilt. For $500 I nabbed them both. So I was ahead to start with. I bought 2 SA Abrasives Porting Kits for like $85. I spent a lot of time on these heads. I made little cardboard templates so I could make all the ports, and throat areas as close to each other as possible. This is my second shot at porting a set of heads, and honestly, I believe they came out looking pretty good. Once I was set on a carb set up, I didn't want to polish the intake due to the chances of the fuel/air not mixing properly. I did polish the exhaust to raise the intake/exhaust flow%. In all fairness I didn't have these flowed after, so I can't give numbers to show a difference. I must also say if when I do this again, I will probably save for some AFR 195's. The only reason being the power potential they have out of the box. Car Craft built a 520hp, 350 with no special parts, just AFR's, roller cam, ZZ4 shortblock, 850 Demon. I know this thread is not about "how to port heads", or "lets see some ported heads", but I will post some pics of mine.

 

Here is another:

 

One more:

 

That's fine that you posted those pics.

That was the purpose of this poll. To try and show those who don't got the money (or the discipline to save it) to buy new heads, that they can get descent gains buy using just a little money and a lot of muscle.

The heads you did look great!!

I can say that I've never bothered fine polishing the ports after I was done. It's one of those things that adds about 4-5hp more, but takes a lot more time. But I'm just lazy. Well actually I just don't think I have the patience.

I commend you because I 've also read that the Vortec heads have to have a lot done, to gain anything. Mainly because they're great to begin with. Kinda hard to make something great, better. Ya know?

AJ

 

That's a really open-ended question, with no single right answer.

It would depend on what stock heads I had to begin with, and what I want to get out of the motor. I'm from the old school too, where there was no such thing as an aftermarket street head, and the only choice available was to work up a set of the best stock castings I could find (or go to the dealer for some new ones). But now, I might rethink that, especially if I didn't already have a good set of castings.

I would tend to make the choice on the bais of economics. If I was adding up the costs of head work, it might look something like this:

• Castings (double-hump with bolt holes for example, or Al L98) - $200
• Cut spring pockets for real valve springs, and guides for Teflon seals - $60
• Decent but not extravagant valves (Comp or Manley for example) - $220
• Screw-in studs - $50
• Springs - $75
• Cut push rod holes - $40
• Guide plates - $60
• General cleanup, valve seat grind, deck true, and other basic machine work - $150
• Guide inserts - $80

We're up to $935, and we haven't touched a port with a grinder; and we still have stock, cast iron heads, with limited flow potential at best.

Compared to that, what does a set of Edelbrock Performer RPMs cost? or World? or TF? or Dart? or Holley? And those are the best stock castings; would it make sense to spend that kind of money on 305 heads, or 70s smoggers? What if I couldn't find those cores, or had to spend more than $200 to get them?

It's all about money and what you get for it, more than just whether it's better to do the one thing or the other. For most even remotely serious street buildups, it makes more sense these days to go aftermarket.

 

Thats another reason I would buy AFR's. I got a pretty good package deal on 2 engines, and a set of Vortecs. I don't think I could get that again. Because of this, it would run the cost of Vortecs way above what I have in them this time around. Between the Crane H-11 springs, Elgin SS undercut valves, Crane locks, ARP studs, porting kits and cutting for studs, I have $380 before the cost of the heads. These heads has 28,000 miles on them, I wasn't to worried about the vlave guides. Now if I had to buy the heads at $500, I am just shy of what aluminum ones would cost. I got lucky with friends hook ups this time around. AJ_92RS, thank you for your compliments.

 

The polishing is quick and a piece of cake compared to the material removal.

40 grit roll, 80 grit roll, flap wheel, medium cross buff, fine cross buff. A few minutes with the first, down to a few seconds with the last.

 

I think the cylinder head quandry would be easier to decide if some thought were given to long term plans. People don't often (and they should) consider what they are going to do with the vehicle. Do they want to continue to work on it and make it faster or will they be able to say "the current power is sufficent". Only then will they beable to objectively determine which is the logical cylinder head choice.

Other factors should be gearing options (both current and future), valve spring configuration and of course the daily driver issue.

I am afraid that each individual will have a different answer (and hence no clear solution) depending on what they think they have already accomplished and what they wish to accomplish. With the choices of aftermarket heads now (and especially some of the ebay deals), someone would be unwise to at least investigate the possibility. An aftermarket aluminum head in most cases, is very cost effective.

 

I spent 25 hours of my own labor on the porting of my cylinder heads, and over $460.00 to r&r them. I saved money by setting up my own valves, and NOT installing screw-in studs. THAT labor isnt included, either! Neither is the $45 that I spent for the SA kit, or the money I spent on the Ingersoll Rand die grinder.

Sure, the ol' Feeble305 now does over 100 MPH in the quarter mile, but will I do it again? Probably . However, I'll do the porting and polishing on a quality set of aftermarket heads, and invest in some flow bench testing. That ought to net some REAL gains, and only cost me an additional $500 over the cost of R&R of stock heads.

(BTW, I'm plotting on buying some AFR210's for my new engine, a forged and internally balanced 385 smallblock.)

 

Who in the heck charged $460 for an R&R?!!!!!

You must live in a very rich neighborhood.

The local race shop told me $185 for a complete R&R for both heads. That's a 3 angle V/J, replacement guides (steel not bronze) & new springs and seals. It costs a little more for replacement retainers, keepers, valves, etc.

Did you have the spring pockets cut for stronger springs? Or have the heads milled down?

It only cost me ~$300 to have the crank ground .010" under, the block bored .030" over, align hone the mains, new freeze plugs, hot tanking, and machine the deck (just enough to true it up).

Some places charge a lot!! I thought I paid a lot. I guess not.

AJ

 

Mill, SA porting kit, Dremel. Mostly Dremel, the mill was used to modify the SA stuff to 1/8" collets and to remove the 'swirl pad' by the spark plug. Did this about 7 years ago, would have left part of the pad if I did it again.



To answer the question, depends. Contrary to popular opinion, porting is no fun. I'd gladly pay someone else to do the cleanup work. It would also depend on what I had to work with, and how much work they needed. Doing seats and guides and screw in studs gets expensive real fast, and you are stuck with a factory used casting. New casting that flows better out of the box than a ported factory casting looks like a real good option at that point. If I have good heads to work with, or I can get them real cheap, I can do alot of the work myself, and I have the time, I'd probably be a cheapskate and do the factory head port job. Otherwise, I would not hesitate to get aftermarket heads, and what the heck... while I am at it, have someone else port them.

Machine work.. I dont know where you are getting your prices, but where I worked was the absolute cheapest place in the area here for machine work and it was even more than the prices you are quoting. And that was 8 years ago. In general, I have found that the machining costs where I live are reasonable, scares me to think someone is doing it for that much less.

 

Well the block work was just done last year. And IIRC, it was $389.

I haven't had the mulla to get the pistons pressed on, the heads redone, or get the lower assembley balanced. I'm a po' man.

OK, how's $40 for pressed wrist pins? And $60 for swapping rod bolts with ARPs (which I already have in hand) and resizing the big ends?

Is that a good price? I've never farmed this stuff out myself. My grandpa always had this stuff done. I just helped him put the stuff back together. But that was back in '80-'89, so those prices wouldn't be any good now anyway, even if I did pay attention to what they were. I was 10-16 yrs old then.

I ain't really done any engine work since he passed on ('89) so it's all new to me again. Basketball, beer, and broads was all I cared about after that.

Maybe I heard the guy wrong? Maybe that's $180/head? But that means that I'd pay more for getting heads done than the block. That don't sound right either, does it?

AJ

 

AJ:

Heads can easily cost more than the block in machine work... think about it.... 16 holes vs. 8... plus, with heads, you have to actually look at what you'r edoing; a block you put in the machine and flip the switch, heads require a great deal more attention to detail, and an overall greater number of operations.

Your prices sound too cheap for an arm's length deal. They would be difficult if not impossible for your average Joe to duplicate jsut walking into a racing shop. Mind you, I'm talking about a racing machine shop, not a "gee boss I've always wanted to work on a transmission" kind of place.

But, I'm certainly not going to call you a liar or any such thing. If you can get your work for prices like that, you need to be building more motors! The rest of us can't, even those of us that speak the language and know how to talk to the guys that do the really primo work. Where you are there's alot of round track activity, and those guys are about a thousand times better at machine work than your typical street specialist.

I gotta agree with madmax about what this stuff costs; no way in hell I would change a rod bolt and work the big end for $7.50. At machine shop rates, that's less than 10 minutes; and that's basically impossible to do.

 

"Where you are there's alot of round track activity, and those guys are about a thousand times better at machine work than your typical street specialist.

How'd you know that? Basing that on the midwest are ya?

That's what this place does. Everyone around here that runs dirt track goes to him cause he's the best in this here neck of the woods.

That's who I'm getting these prices from. Alber's Automotive. People come from all over the midwest to have him do the work. He's (his shop) is very good. Small, but good.


AJ