HEADS OR TAILS

[speedy]

Im working on a /6 head so far open the bowls straitened out the ports blended in around the valve guides polish the comb.chamber and polish the exaust side.my question is do i polish the intake sides.some one told me it wouldnt mix the fuel properly if its polish to a mirrer finish .Now this is a /6 and with the long runners on the intake manifold and useing a bbd 2brl carb I would think this wouldnt matter.Well its not a B.B. BUT it beats watching television.

[DartGT66]

Some people think that if the intake ports surface is too smooth you will have air/fuel separation problems. I wouldn't let that bother, first of all noone seems to be able where is the limit, what is too smooth and what is not. And more importantly, the wall surface smoothness does not do much for the flow. Comparing a rough ported and a ported & polished port in a flow bench shows 0-1% difference in flow. In the exhaust port the smooth surface is used to avoid carbon build up. I hope you are going with bigger valves with your \6, porting the head doesn't do much without them.

[Tim_K]

Speedy:
I'm currently working on porting out a /6 head also. I'm building a 273 for my daily driver '71 Valiant, and just have to do something to the /6 in the meantime. It already has the factory aluminum 2 bbl. intake, a 318 BBD, 181,000 miles, and headers and large exhaust system. The head is stock, and clearly the current restriction in the system.
I'm using my Dremel set for all the work with 1/8" size tools. I'm almost done with my porting. I used a tungsten carbide cutter for 95% of all the work, and used rounded/tapered stones (the brown colored ones) only for the final clean up pass. They work good for smoothing out all the irregularities left by the carbide cutter, but they wear out fast. About 15 minutes per stone for me.
As far as polishing the ports goes, I'm not worrying about it much on this head I'm doing. A quick pass with the stones to smooth down all the rough casting, and that's it. The exhausts I'm doing a little smoother than the intakes, but the intakes are now very smooth compared to stock.
I also wouldn't worry about the intakes being too smooth and messing up the fuel/air mixture. The inside of the stock aluminum intake is about as smooth as it gets, and it came like that from the factory.
Depending on which cylinder you're looking at, you have about 10 to 16 inches of intake manifold ahead of the 3 to 4 inches of port. Plenty of ram effect to get it all through.
Since I'm doing this head cheap, I'll be using the stock size valves and camshaft. Don't know how much additional power I'll make doing it like that, but we'll see. I'll be posting a new topic on it when it's done and running.

[speedy]

I would like to use the mopar bigger valves but 42.50$ a valve !!!! I can rebuild the hole motor for less than that .the valve length is 4.687 but try to find specs". on other valves to use in this application.Im looking for a 1.5"exhaust and something around 1.740 intake.now i can show you millions of adds for this size but what is the length 'stem and how many grooves for the keepers.I have seen other valves as low as 2.95 $ so if you shorten it and cut new grooves its about the same price .I paid less money on my 360 heads .Im running out of options. I took a lot of meet out of the bowls and ports the /6 head was really restricted im sure it will wake this old dog up. MOPAR MUSCLE did a build up on this motor in my opinion was terrible no back yard mechanic goes out and buys a 1100.oo$ preped head for a /6.WHY!!!AND why would you buy 9to 1 pistons when can mill the head .090 with no problem.and most of all put it in a full size short bed (TRUCK) . that rag is getting on my nerves with all their trailor Queens and 10.000 mile cars .Drive the cars thats what MOPARS are made for especially when i see a 68 69 roadrunner with puney hub caps and no miles. common grandma didnt buy this car to go to church on sundays with a HEMI and a 4speed.Well you can see this valve problem has got me pritty tic off especially after putting about 150hours in the head .

[DartGT66]

The price of the valves is disgusting. I woudl have installed bigger valves in to my engine if the price wasn't so high and hadn't I been in such a hurry to really concentrate on the subject. Now I know I really should have done that. I know people have used other valves in the /6, maybe polys? Anyway, you should find a correct length replacements to keep things cost worhty. But it's actually nice to notice first hand that building a /6 isn't cheaper than building a V8. And an all out /6 performance is about the same as that of a bone stock 2-barrell 360, except that the /6 needs XXXX rpm converter and 4+ gear ratio to perform.

[Tim_K]

Speedy:
Have you been to www.tailfins.com? That is a slant six web site. It was recently re-engineered. They lost a lot of good tech articles in the process, but the last time I was there, they still had all their 'Slant Six Racing News' articles. Some wild tech stuff in there. Check it out.

Valve prices ? I have a lot to say there. I called Mopar Performance's tech line a year ago to tell them of the 'misprint' in the parts catalog, what kind of person would pay $42 a valve ? And why didn't they sell them as a group of 12 to do a whole engine at a better price ? They didn't really have an answer, I'm sure they didn't care. I told them what they could kiss of mine with prices like those. Well, I don't care about their profit margins or costs, I'm NOT paying $20 per valve, much less $42!!! They can keep them at that price. I'll go elsewhere for mine. And they aren't even all that much bigger than stock valves! 1.625 vs. 1.70 intake, and 1.375 vs. 1.44 exhaust ? Why bother ? Same thing for the ported head. Sorry, the 'sucker' line is over there. I'm in the 'people with at least SOME brains' line.
On the tailfins.com site, you'll find many good stories. One of them shows how a guy fit 1.88 intake and 1.50 exhaust valves in his /6. I think they didn't take much work to do, maybe a notch in the cylinder wall or something.
I thought about how to put big valves in my /6. I thought of small and big block valves. 318 valves would be great, but they are different length stems. If a longer valve were cut down and had new lock grooves machined, you'd have to re-harden the valve tip. Or maybe use lash caps. I don't think there's any cheap way out, but there are gains to be made in hp with big valves.

Now let's talk about the 2 recent /6 buildups in magazines.
The Mopar Muscle article was o.k., I liked reading it, but I questioned pretty much everything they did. They tried to make it sound like they got a whole lot more power, but they really didn't. I was happy to see a slant six article, but was very unimpressed with their results. It seemed like they had a whole lot of money to spend and were more interested in making a pretty truck than a fast one.
The Car Craft (Chevy Craft, Camaro Craft) article by Matt King was an example of total incompetence in my opinion. They didn't use a Sure-Grip? They had an inadequate fuel system? Gee, I wonder why it didn't go any faster! They tried to save money by not cutting down the head much so they could re-use the stock pushrods ?!?!?! Almost no increase in compression with a bigger cam (which they didn't even list the specs of, I think it was a 276 degree Clifford cam, judging by the valve lash specs they DID print).
We need someone good, like Rick Ehrenberg at Mopar Action to do a good /6 buildup. I'm sure he could show us how it's done. If one of the magazines would cover the costs, I'd be happy to do one myself!
Yes, I agree that even a built up /6 would have some trouble beating a mild 360, but wouldn't it be cool to race someone off a stoplight in his Phord or Shivvy or Jap car, and beat him with your SLANT SIX ? Some people where I work have wanted to see my engine because they didn't think a /6 could sound cool (exhaust). They saw the aluminum 2 bbl. intake and headers. No chrome. That was too much for them. Freaks everybody out, and there's more to do yet. Wait 'till I can burn tire out of the parking lot with the /6!

[This message has been edited by Tim_K (edited January 11, 2000).]

[Dr. Righteous]

I share your interest in the Slant6. Its a very cool and almost bullit proof motor.
BUT my take on slant6 performance is alittle different. Because it only occupies one side of the engine compartment, a turbo setup would be easy to plumb in.
There is plenty of room to work and modify the exhaust manifold to accept a turbocharger. What do you think?

[Elwenil]

Good call Dr. I'd swear I remember one of the Mopar mags doing a feature on a turbo'd slant 6. I'll have to look through my stacks of mags to see if I can find it. Anyone else?
~Elwenil~ ~.\|/.~

[340king]

You are right on. I have seen one of these beasts. The guy did all the work himself and had the combo nearly worked out when he wrecked the car. If I remember right he used the turbo off a 2.2l and boosted the gate. I can call his dad and find out if you're interested. His setup was a real low buck deal. It really worked well as he dusted many v-8 powered cars with it.

[DartGT66]

Actually turbo charging was my original plan, but since I was forced to rebuild the engine in a hurry, I chose the traditional route. Didn't have the time to build the header for the turbo, or the money at the moment, the rebuild cost pretty much itself. Turbo gives great power for everyday driving, perhaps I will put turbos to my RB in the future.

[speedy]

Well i called ramchargers 'mancinis and a couple other places today ,no luck trying to find any valves,so i emailed cliffords to see if they could help . I was looking into that turbo combo and this is a great idea.The bone yards are full of 2.2 turbo's around hear im vary interested if 340KING could provide some more info i would greatly appriciate it.And Tim K i been checking out tailfins for some time now pritty (Kool) IN their tech line #7 they have a picture of a turbo /6 i think it was 386 h.p. Now that would ROCK.I seen the 2.2 push 300 ponies so i bet that combo on the /6 would be worth an extra 100 to 150 H.P.And still get good GAS MILAGE.It sounds like my winter project may last till spring!!:O YA' TIM have you had any problems with your headers or header 6 in 1 or 3 into 1 ? You Know DOUG Dultra has that split manifold for duel exaust i bet you could run one into the turbo .I really don't know that much about them so i better read up as much as i can on this .I'm glad to hear i'm not the only person out hear to beef up a /6.But im the kind of person that would try to get more power out of a lawn mower .

[Tim_K]

Speedy:
To answer your header questions, I have been using Clifford Performance STREET ROD headers on my '71 Valiant's /6. They are a dual design, 3 into 1 for the front 3 cylinders, and 3 into 1 for the rear three. The two halves are seperate from each other. They've been on my car for a good 3 years and about 67,000 miles, driven in all types of weather, and they've worked very well for me. No rattles or leaks. My original system was a full dual 2 inch setup. Both pipes came off the headers, down and alongside the transmission, both on the drivers' side (THIS WAS A 4 SPEED TRANS.!), and the right side pipe crossed over, behind and under the driveshaft. Dynomax Super Turbo mufflers and auto parts store 340 Duster tailpipes, with 18" extension pipes, since I wasn't using chrome tips. The only tight spot was where both pipes had to go past the trans. crossmember. It fit around the clutch and shifter linkage fine. The dual Super Turbos sounded ok, but after about 10,000 miles, they started to get loud. If you had to haul anything with the trunk lid open (tied down with rope) the resonance would blow your brains out!!! Finally, after about 3 years, one muffler was rotting out pretty good.
I took this opportunity to redesign the whole system. Now, 2" pipe comes off each header collector, goes down to beside the torque converter (more or less) where they reverse-Y into a single 2-1/2" pipe with a new Dynomax Super Turbo muffler. This sounds much better and is quieter than the dual system. I made the effort to minimize restriction in the single system by using 2-1/2" pipe like a 273-4 barrel. Only complaint now is that the 2-1/2" pipe is kind of a tight fit between the frame rail and gas tank, but that's a minor point. I'm much happier with the H.P. single system. I would have liked to put a Flowmaster muffler on, but it would be kind of embarrasing to have a car sound that cool and only run mid 18's.
Oh yeah, you only asked about the headers. OK. When they were in my other car, a '72 Valiant (the 4 speed car) it had manual steering. No clearance problems anywhere. When that car's trans. crossmember finally rusted out and collapsed, I transferred everything over to a twin car '71 Valiant. Motor, radiator, exhaust, 8-3/4" rear, EVERYTHING. Except now a 904 trans. This car has power steering. The headers will rattle against the steering box at 1 small point if you put the car in Reverse. Here's how I cured that problem.
Taped a small piece of sheetmetal over the P.S. box at point of contact, to avoid sharp edge. Have friend put car in Reverse, hold brakes on and tach at 1500 rpm to load headers against box. Remove air cleaner. Take a 2 foot long piece of 2 by 4, hold edge against top of rattling header tube. Take 8 pound sledgehammer in other hand, and WHAM! WHAM! WHAM! the 2 by 4 a couple of times. Result? A nice, clean, neat, small ding in 1 header tube. Not much of a dent at all. No more rattle, problem solved.
Since I was using a factory aluminum 2 bbl. intake manifold, the mounting tabs had to be ground down slightly for proper alignment on the head along with the headers. Not much, just a few small repairs. Not even all the tabs had to be touched.

The last time I looked, I think Dutra wanted something like $400 a set for those split header / manifolds? I don't remember. I paid $180 plus U.P.S. for my brand new, good quality, fully mandrel bent and welded up set of headers. I got my money's worth a year or two ago.

[speedy]

TIM K i was looking at those same headers im glad to hear you haven't had any problems with them but i thought they cost around 350$ .I was wondering what you did about the heat riser coming off the manifold.I found a guy on the mopar web that used 1.88 and 1.50 valves .he said that most people are using 1.72o or 1.75 int. and 1.5 or 1.6 exh. he said he thinks the intake came off a 383 and the exh. came off a 340 or 360 . He's got a build up on his motor at www.DEVILDUSTER.COM.Well i still haven't recieved a email from cliffords to confirm anything as of yet.I'm going down to talk to my machenist tomorrow i'll let you know what he has to say. YOU know those half inch round sanding disk for your drummel you slide them on the rubber and tighten the screw on the end boy talk about a mirrer finish .all so you can take the rubber off.you can buy this stuff they call scrubby's sometimes you see this matterial on one side of a sponge red.brown.or green.take a pair of sizzors cut out about 5 or 6 pieces the size of a bottle cap then put the screw threw the middle of all 6 pads then screw it back on the drummel .MAN this works great and cheep too.(hard shine)in the ports.

[Tim_K]

Speedy:
When it came time for me to decide what to do about the heat riser that operates the choke, here's what I did.
I eliminated it. I now operate the choke like this:
I found a very light throttle / kickdown return spring about 3 inches long. I hooked one end over the fuel line at the front of the BBD carburetor. I then hooked the other end to the linkage on the side of the carb. where the old heat riser hooked up. I adjusted the spring by stretching it until it had just enough tension to pull the choke plate shut when you open the throttle with the engine turned off. When you start the engine, the vacuum pull-off opens the choke fully. It is all automatic, I never touch anything. Only thing to remember: If you go to start the motor when it is hot, and forget and pump the gas pedal anyway, the spring will snap the choke shut and you will flood the engine. Then you have to pull the air cleaner, hold choke and throttle open, and crank it until it starts. I only did that a couple times before I learned.
As for hot air to the carb. , here's what I do there.
I run it with no carb. heat all year except in winter. It will run very badly with no carb. heat in cold weather. I went over to the local hardware / home center store, and got 4 feet of 4 inch aluminum flex tubing. Like that stuff you connect to the exhaust of a clothes dryer. It has a wire in it to keep it round. I squeezed together 3 or 4 inches of one end, then hose-clamped them to the #1 and #2 header tubes right in front of the collector. I reached into the air cleaner, where that wire goes through from top to bottom to open the hot air door, and bent the wire so the door was always partly open. I ran the 4 inch aluminum duct into the main inlet of the air cleaner (Super Six unit). Poked small hole in between 2 of the wire loops for extra airflow. The engine immediately ran great all winter with its new hot air system.
When I got my headers, I paid $180 for them. I got them directly from Clifford, not some other dealer. That was over 3 years ago. Don't know what their prices are like today.

[speedy]

tim k. i went down to the mach, shop yesterday and the guy said to bring the head down and he said he would have no problem finding over size valves to fit .i told him i would like the head milled .060 ,ALL new valve guids ,harden seats.3 angle valve job ,new springs,check for cracks,new valve stem seals,and assembled.He said it would be rite around 500 dollars.I think thats not a bad deal considering the mopar preped head cost 1100 and thats with smaller valves . BUY the way that was some pritty good idea's for the heat riser. i'm thinking about making a box under the manifold and piping in 2 3/4 inch lines from the headers into the box from the bottom and using the butterfly from the old exh. manifold .Do you think i will have the room im not sure if the headers would be in the way.sorry i didn't write back yesterday i was Christmas shopping for 9 hours and lived to threw it.MAn their are some real #@$%$^&$% out shopping this year.

[Tim_K]

Speedy:
Make sure the valves that guy finds have the same length as stock slant six valves. I'd like to find out what oversizes are available, and from where. And from what other engines.
500 dollars sounds like a lot of money, but I guess if he does it right, it's probably worth it. I don't think there will be much room under the intake for any kind of heating box. I didn't use one last year, and the car ran fine. I was thinking about routing another one of those aluminum flex hoses from the rear header to under the carb and kind of just wiring it in place, but I don't think I'll need it.

[speedy]

Tim K. from what the the guy at UNITED AUTO parts told me that cliffords selles a adaptor to take the place of the heat riser.I'm not sure how it workes but i know you pipe it in from the headers . i guess thats why he quoted me a price of 300$$.But i would rather pay 180 and pipe it in like you did.I don't have any idea what valves he'S going to use but i will let you know as soon as i find out!HE said he mite have to use a Phord or Chebby valve .

[Tim_K]

Speedy:
While reading my latest issue of Mopar Muscle, one of the articles had a picture of some Ferrea valves, and it says Ferrea will make custom valves. I'll call them today and see what they say about /6 valves, maybe something like a 1.80 intake 1.50 exhaust with stock length stems, maybe a smaller diameter stem. I'll let you know what I find out.
*ALSO* - yesterday, I posted my 50th response, thereby promoting me to full Moparchat Member from Junior Member. Hooray for me. Too bad there aren't higher levels to shoot for.

[Tim_K]

speedy - I found out that Ferrea Valves (954) 733-2505 can make pretty much any valve we want. Price range of $28 to $34 per valve, depending on how much machining has to be done. They say they have valve 'blanks' to start from, and make valves to your specs. Different stem lengths and diameters, tulip or nail head, valve diameters, you name it, they claim they can make it. That would cost about $400 for a complete /6 engine set. In order to cheapen it up a bit, I wonder if stock /6 intake valves could be cut to 1.50" (from 1.625") and be made into exhaust valves?
Even at $34 per valve, I'd rather get them made MY way than pay $42 to M.P. for barely oversize valves!

[speedy]

TIM-K great job on the 50 i read your speedo posting excellent job that idea about the use of the intake valve for exh. i was thinking about that myself as a matter of fact .BUT you know that's a diferent type of valve i think it would work i bet it would flow better ,even if it was ground to 1.550 that's only .035 off the seat, i don't think thats enough to hurt the hardness .plus the older valves should be harder anyway the only thing this would affect is the seat .it mite sink in the head ferther but that would be better anyway isn't PRO a machinest maybe he might know.I posted more INFO on YOUR VAVES POSTING

[panic]

IMHO try to use valves with minimal tulip (10-12 degree underhead angle, 3/8" stem to head radius) for best results. Also "pro-flo" (stem diameter reduction in bowl area to 5/16") is probably a good idea. Donovan (310 320-3772) has made excellent custom stainless valves for me in the past, but $$$, will do anything you want.

[340king]

Well, I just talked to the father of the guy I told you about in the previous post. He said that he used the 2.2l turbo like I told you, but went quite a bit farther with it. Here's how he did it.

First, he had installed a very large cam, which he still has, from MP I'm told. Then he built his own exhaust for the turbo. He ran the engine in an '80's D100 truck. He started with a stock carb and worked with it for a while. The engine ran fine, but stock carb size was insufficient to support the turbo draw.

He always ran a water injection system with the turbo to avoid detonation. A lack of water killed the pistons on one particularly hard pass.

Anyway, he upped the anti when he manufactured his own manifold and ran Datsun mechanical fuel injectors from a 240Z. One set wasn't enough, so he put two sets on the thing. While it was running, it really made some awesome power. Now I know this is probably way beyond anything that you may want to do, but I think you could use his initial setup and run a larger carb and get by just fine. I can get his name and address from his dad if you like and e-mail you with it.

He is now driving an '85 caravan with a 2.2l turbo engine stuffed in it.

[speedy]

340king i think im goimg to stick with a carb till next fall i sunk alot of money into my other Duster plus i need to do some more reserch on that but i'm sure some of the other guy's would like to know .Panic, could you explain this in more detail for me i'm not sure how to go about this with the stock intake valve.I went back into the exh. ports open them up some more big difference i had a exh. manifold off a 74 duster and port matched it about .100 more on width and about .060 on the long side .i believe this was the largest exh. manifold they made on the /6.im going to use the same headers TIM-K USED.O YA tim if you look at a 83 84 318 on the exh. manifold on the drivers side theirs a heat sheild to pipe in hot air to the air cleaner, that should fit close to the the head on one of your header pipes you could probly use a 318 air cleaner also that should creat enough heat to take the place of the heat risor .

[speedy]

tim-k i need your help i was mesuring up the intake ports on the head and compaired them to a aluminum manifold 1 barl carb and their's a big mismatch . the one im going to use is on the car super six 2barl .any way the manifold is .130 smaller on the short side and .120 on the long on all six runners.now does my super six have larger runners on the manifold if not should i open them up to match?PANIC thank you for the e-mail

[DartGT66]

You should port match the intake manifold to the head.

[Tim_K]

Speedy:
I haven't checked the intake manifold gasket surface for port dimensions yet, because it is still on the car. When I change heads I will give it a quick going over if it is much smaller. But if it is smaller at the end, it is probably smaller all the way back to the carburetor, so I don't think it would help much to flare out the ends. When I got my replacement head and intake gaskets, I used the intake gasket to measure and mark the ports for boring out. The intakes needed a little, 1 long side and 1 short side, but the exhausts needed all 4 sides to be ground out to match the gasket.

[DartGT66]

According to an old mopar performance catalog matching the intake ports to the size fo the ports in the heads is worth 5-10 hp. In my case, a '80 2-barrell intake and head there was no big mismatch.

[speedy]

DARTGT-66 i wonder if the 79 is the same intake?I know the aluminum one barrell i have can be opened up, but i gasket matched the ports plus their was a approx. a .200 to .250 taper choking the first 1.5" of the port on the intake and exh. so after i straitend that out and blended it all in it was way off ,but i think this will make a large gain in flow .i wonder if theirs a diference between the m-1 and the super six besides weight .But i can see how you could pick up 5 to 10 hp or more no problem, i was wondering did you open the ports on yours ?

[DartGT66]

In my case the ports were the same size, so I didn't have to do but minor matching.

[Speedy#1]

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