Stocker Head confusion

[mannymen]

How and the heck would stock eliminator heads have 3000-4000 plus dollars worth of work done to them without PORTING? Can someone enlighten me?

[Mike Carr]

I've heard that the majority of the cost is for the work done to hide any illegal modifications done to the head.

[greg fulk]

PORTED!!! No one porting anything here! Enhanced maybe but NOT ported!

[BlueOval Ralph]

You acid porting and shot peening and new cutter work.

Originally Posted by greg fulk

PORTED!!! No one porting anything here! Enhanced maybe but NOT ported!

[mannymen]

The reason I ask is that I'm looking at putting together a stocker 427 in a TRUE FACTORY stock manner. Using true factory stock 291 heads, crankshaft, intake, block and prepped 780 carb. I guess i should be able to get 675-715 HP out of that. Yeah Right!!!

[Chris "drooze" Wertman]

Originally Posted by mannymen

The reason I ask is that I'm looking at putting together a stocker 427 in a TRUE FACTORY stock manner. Using true factory stock 291 heads, crankshaft, intake, block and prepped 780 carb. I guess i should be able to get 675-715 HP out of that. Yeah Right!!!

***Disclaimer*** Not knowing anything I would advise you take the following with a grain of salt since its said I dont do or know anything......

I dono what others do, but since things on our car are going to be scrutinized as much as they are.....here is an easy way to ring up a LEGAL bill on the heads depending on how much you do yourself.

All items checked with the NHRA of course prior to doing them.

Rocker (and Shaft if you have em) Coating and hardened shafts. (200-500)
Valve backcutting, or custom valves the way you want em to flow ($400-1000)
Treatment and coating of valve stems to full open, thats legal as long as noone of the coating is in the airflow, since its done for friction reduction youre about 60% effective there ($100)
Backcutting of valve guides so you only have a small section at top and bottom in contact with the valve, but still allow it to be stable at high RPM (the top groove is angle cut downward allowing passing gasses to form a turbulance zone inside the guide with its direction back twoard the combustion chamber)(Labor $100-300)
Coating the guides after theyre cut of course, ($50-100)
Seats of better seal charachteristics than stock.($200-500)
Finding the best springs you can with the rate and stability required for your application, Rate is EVERYTHING...id take 20 on rate instead of 10 installed height pressue every time.(200-500)
Lowest mass moving items available, retainers, cant run Ti, so looking into moly flowered and drilled, ($100-250)

Be careful of coatings, theyre like snake oil and someone will sell you anything, some of its useless, in the Aerospace industry DLC (Diamond Like Coating) is used but it has it places, not for everything, double or triple coating costs for DLC stuff.....

I just picked up my completed heads today, well see how they run.....Several of those items are waiting till the new set of shafts and castings come in.

I hear well, I hear a lot some of it is I dont know ****, but on the MC side these things payed dividends that were appraent, the effect on a larger engine in terms of percentage may be smaller as the engine is spinning much slower even at 9k , but I will take all those "you wont see much difference" items and add them up anyday......my last Honda CB350 Motor (326cc's) was 65 hp across dynos.....65 hp.....the motor got "known" and was sold for more than I had in it, not because they didnt know how to do it, nothing was secret, they just didnt want to have to do it all themselves.....Half the work in the motor, or more was in the head. And the casting was never cut.

P.S. (Some coatings that are actually effective you can do yourself, buy a cheapie Salvation Army stove , and put it near a door so you can waft the supposedly "non toxic" fumes out the door) Caswell plating sells some of TechLines stuff retail but not all.

Testing the effectivness of friction coatings is easy to set up to do yourself on reciprocating parts, its all about tempereature, set something up to spin or move something for X amount of time, then test the temperature, apply different coatings to either the same part or parts of the exact same size and finish and test again, a sewing machine rigged right from your Salvation army is good for things like rockers and valves to help build heat in a in / out motion. Usually you need a bigger motor on it to get it up to a speed thats effective , and make sure its one of the old all iron jobbers.....

[Dwight Southerland]

Beyond the cost of 'enhancements', when you consider machine work followed by flow bench work to find the best combinations, @ $70-$100/hr it doesn't take long to run up a bill. It's the time, not the amount of modifications. Before the flow bench era, just the cost of precision quality work was expensive. Now, if you want some real development done on heads, the cost of the time will kill you. I have spent 40 hrs. easily just trying different seat angles/approach angles/valve head configurations for a head. That's just to find what posts the best numbers on one cylinder. Then you have to repeat that work seven more times. It may be fun, but it's also a lot of work and I get paid for it.

[Alan Roehrich]

Dwight, that was a nice start on the job in question.

I'd like anyone who questions the price charged for a set of legal Stock heads to please post each operation that is involved in building a set of Stock heads, what equipment is required to perform that operation, how much that equipment costs to own and operate, and what the other overhead costs of a shop are. Next, please post a list of all of the parts required. After that, please post how long it takes to learn to do the job properly, and to know what to look for and how to find it.

You know, racing is just a hobby, to some people. However, it is not just a hobby to the people who do the machine work and build the stuff. They have to make a living at it. Just like you have a family to feed, clothe, and shelter, so do they. And if they're working on racing parts, odds are, they'd like to race, too.

If this stuff is all so simple, try taking your stuff to a local run of the mill machine shop, or even most speed and machine shops, and see how fast you go. It's not that they don't cheat, and the race shops do. It's called experience, and attention to detail.

[Dragsinger]

"Backcutting of valve guides so you only have a small section at top and bottom in contact with the valve"

a little known speed secret!

[Chris "drooze" Wertman]

Originally Posted by Dragsinger

"Backcutting of valve guides so you only have a small section at top and bottom in contact with the valve"

a little known speed secret!

I wouldnt think so but it limits the friction placed on the flat of the stem against the wall of the guide, with even a bit of runout on the guide, you have to replace the guides much more often but so what , on a small 4 valve motor it makes a big difference, on a 2 valve per cylinder pushrod motor even more since there is deflection caused from the rocker friction at the tip of the valve, valves arent pushed 90 degrees straight down, rather they "tack" down the guide from the rocker, the rocker has friction at the tip and pushes the valve away from its center of leverage, I learned it when I was 12.........I think, I learned it from one of Smokeys books that was all I read pretty much....coulda been from 1 or 2 other MC racing books though....

If i can read it, implement it and test it and see results so can others, no secret there.....

"Shrugs"......