Do it ur-self 1.6:1 /6 rockers

[Bill Dedman]

http://www.pentastarparts.com.au/store/index.php?l=product_detail&p=811

Even at the favorable currency exchange of $1.32AUS/$1.00US, thats still
$1023.00, holy sniekes !

That is the reason I built my own...

The fact is, turbocharged slants have several things going for them in the area of valve train and camshaft "technology."

First off, the most powerful turbo'd slants I know of (500+ hotsepower,) don't perform well over 5,500 rpm, so, high rpm, and the valve springs necessary to achieve it, just aren't needed. That enables several other benefits: Because there isn't a lot of valve spring pressure, stock lifters,pushrods and rocker arms are all that's necessary. If you want more valve-lift and effective duration, you can always take a set of stock rocker arms (1.5:1 ratio) and modify them, like I did, to get a set of 1.6:1 arms for not a lot of money. See photo:
I used a vertical mill (Bridgeport clone) and a .104" metal-cutting blade to alter mine, (after having them annealed by a heat-treating facility,) then had them t.i.g.-welded . Last step was having them heat-treated back to their original Rockwell-hardness. They were case-hardened a the factory.

They aren't roller-tipped, but this is a race-only engine and won't see a lot of driving miles, so, I think it will be okay.

Because so little valve-spring pressure is necessary (I use Crane 340-replacement springs for their increased-lift before coil-bind,) camshaft life should not be a problem with non-roller lifters if a modicum of ZDDP is added to the oil.

And lastly, instead of a 1.000 rpm, ragged idle like you'd get with a long-duration "full-race" N/A cam, you get a smooth, 450-rpm idle that sounds almost like a stocker.

The benefits of turbocharging a slant six are manifold.... no pun, intended. :cheers:

 

[Killer6]

Lol, well, I dusted this thread off and pulled the cork on it to see if there are any
running yet. As entertaining as it is to read your turbo pimping, I'm primarily interested
in the success rate on long-term use, ratio accuracy arm to arm, and how the oiling to
the adj. was maintained. I have no idea what someone is charging to anneal and re-
harden, but if I consider my time cutting-welding-grinding/drilling/filing and running them
back and forth + that........they had better work......and well!I know abt. Cox bros...

 

[Bill Dedman]

Lol, well, I dusted this thread off and pulled the cork on it to see if there are any
running yet. As entertaining as it is to read your turbo pimping, I'm primarily interested
in the success rate on long-term use, ratio accuracy arm to arm, and how the oiling to
the adj. was maintained. I have no idea what someone is charging to anneal and re-
harden, but if I consider my time cutting-welding-grinding/drilling/filing and running them
back and forth + that........they had better work......and well!I know abt. Cox bros...

I am sorry I don't (yet) have any information as regards ratio-accuracy, lubrication or long-term longivity; all good, legitimate questions.

Maybe I'll have a chance to measure the actual ratio of these pieces before racing season starts. I bought two (actually, digital) dial indicators to mount on the jig I built, for just such a purpose.

But, realistically, as I said, in my case (high boost..... 20# and up,) I don't think the actual ratio, be it 1.58:1, or 1.62:1) will matter much. Just my opinion.

Then, there's the fact that my engine will never see "street miles" (it's JUST a drag race engine) and the lubrication issues that would be significant on a motor that got driven hundreds (or, even thousands) of miles would never be displayed.

I don't KNOW that the annealing process was even necessary... it just seeemed like a good idea, to me. I don't think Aaron annealed his, before he cut them.

Tom Wolfe built a set and ran them with no issues.

The outrageous amount of money asked for the Aussie sets are reason enough for ME to experiment.

 

[Killer6]

Well, I for one wouldn't mind seeing you toss that set on after a couple passes,and get a real
-time mph read to see. Also I would be a bit careful in your comfort level with "avg." HP springs
with the higher boosts. Remember 20#+ of boost times the area of the backside of your int.
valve could easily mean 40-50# of load trying to unseat your valve against say, a 110# seat
load spring. You can do the math so..... also as noted in mopars books, the lift rate is just as
impacting as rpms are to valve/spring stability/ability.
Sadly, I am aware that one of the cox bros. passed away, I am not sure if there will be any
more rockers from that outfit again. I may make that phone call next week if nobody chimes in
with an update...... I don't recall the $ at the time for those, were they at least more reason-
able? I mean, I don't mind dropping the coin for top parts if they perform on par w/my invest-
ment,accuracy-quality-reliability wise.

 

[pishta]

Bill, whats the chance a cast 1.6 shaft rocker could be adapted? Too fat? Never even looked at them in that light.

 

[Bill Dedman]

Well, I for one wouldn't mind seeing you toss that set on after a couple passes,and get a real
-time mph read to see. Also I would be a bit careful in your comfort level with "avg." HP springs
with the higher boosts. Remember 20#+ of boost times the area of the backside of your int.
valve could easily mean 40-50# of load trying to unseat your valve against say, a 110# seat
load spring. You can do the math so..... also as noted in mopars books, the lift rate is just as
impacting as rpms are to valve/spring stability/ability.
Sadly, I am aware that one of the cox bros. passed away, I am not sure if there will be any
more rockers from that outfit again. I may make that phone call next week if nobody chimes in
with an update...... I don't recall the $ at the time for those, were they at least more reason-
able? I mean, I don't mind dropping the coin for top parts if they perform on par w/my invest-
ment,accuracy-quality-reliability wise.

This is not rocket science. I am just one old (REALLY O-L-D) guy, trying to have a good time and embarrass a few Corvettes... LOL!

If I were building an NHRA Competition Eliminator car, and had serious aspirations about setting a national record, I'd be going about it totally-differently, but, my plan is to just see how much bost I can shove into this thing before it blows up (and, it will...) but, I am not totally oblivious to trying to do it "right." For example, you have a really good, valid, point about boost affecting valve spring pressure, and I WILL address that issue, for sure.

But, my advice (and, nobody asked,) is, just build your own 1.6:1 rockers; it really isn't hard at all if you can weld, and if you can't, hire it done; it's not that expensive.

But, an experimental engine with a much-longer duration cam MIGHT work well, and could make the 1.6 rockers a moot point. The potential for mechanical variations on this forced-induction/slant six theme are endless.. We haven't even scratched the surface.

For someone with more smarts than I, EFI is an obvious choice... carbs just don't go well wiith blow-thru, because that was never a part of their DNA...

The best part of this whole exercise, is the rewarding way slants respond to boost, even when a moron like ME fools around with it; It is just SO rewarding.... even in my ignorance.:cheers:

 

[Charrlie_S]

The outrageous amount of money asked for the Aussie sets are reason enough for ME to experiment.

T&D Machine has 1.6 ratio slant six rockers available. Last I heard, about $800 per set.
http://www.tdmach.com/

They are not listed online, you need to call.

 

[pishta]

I looked a the possibility of using a generic crane 1.6 rocker on a slant. It may be possible IF you move the shaft in 3/4 inch, but that only addresses the nose reach to the valve. No telling how the pushrods would fit down there. Plus the shaft is too big anyway. Wonder why they changed the shaft OD when they designed the small block? Slants just a hair bigger. Bill, It must be nice to be retired and have the time! ;-)

 

[mguner]

Anyone ever checked on an old 282 International 6 to see if those rockers were a fit? I know they were a shaft mount.

Part#323727R91

[/IMG]

 

[Bill Dedman]

T&D Machine has 1.6 ratio slant six rockers available. Last I heard, about $800 per set.
http://www.tdmach.com/

They are not listed online, you need to call.

Thanks, Charrlie! That's still a lot of money (to me) but, a lot more like it...

 

[Bill Dedman]

I looked a the possibility of using a generic crane 1.6 rocker on a slant. It may be possible IF you move the shaft in 3/4 inch, but that only addresses the nose reach to the valve. No telling how the pushrods would fit down there. Plus the shaft is too big anyway. Wonder why they changed the shaft OD when they designed the small block? Slants just a hair bigger. Bill, It must be nice to be retired and have the time! ;-)

PISHTA,

Just wait; you'll see... I thought I'd have lots of time for foolishness like this, but, I have found that I am busier then I ever was when I was working a 40-hour week...

You'll see... you'll see! :banghead:

 

[Bill Dedman]

Anyone ever checked on an old 282 International 6 to see if those rockers were a fit? I know they were a shaft mount.

Part#323727R91

[/IMG]

Boy, those sure look like they would work.

Where is info about the shaft-diameter, fulcrum-to-valve-stem and ratio available?


Looks really interesting! Thanks!

 

[emsvitil]

Anyone ever checked on an old 282 International 6 to see if those rockers were a fit? I know they were a shaft mount.

Part#323727R91

[/IMG]

Does it have the oil passages that the slant rocker has?

 

[Killer6]

I looked a the possibility of using a generic crane 1.6 rocker on a slant. It may be possible IF you move the shaft in 3/4 inch, but that only addresses the nose reach to the valve. No telling how the pushrods would fit down there. Plus the shaft is too big anyway. Wonder why they changed the shaft OD when they designed the small block? Slants just a hair bigger. Bill, It must be nice to be retired and have the time! ;-)

All the Mopar V-8 rockers are way too short, and the pushrods(if you're using 3/8 chrome
- moly), are already perilously close to the head near the deck. There is no room for that with1.6 moving them in even closer. That IH rocker looks longer and to be a 1.7?? ratio, i'll have
to check on shaft dia. & oiling provisions/design. 8 bills from T&D don't sound bad if that's thecase, depending on what is included, the PP&R's have billet hold-downs,shaft,spacers etc. sothe extra $230 may involve those items....
You can grind clearance for the p-rods, but I don't think near enuff for a V-8 rocker,not
to mention moving the shaft that much isn't feasable or complimentary.As far as SB shaft
diameter, it shouldn't be too hard to hone al rockers up if they were an opt.

 

[Bill Dedman]

All the Mopar V-8 rockers are way too short, and the pushrods(if you're using 3/8 chrome
- moly), are already perilously close to the head near the deck. There is no room for that with1.6 moving them in even closer. That IH rocker looks longer and to be a 1.7?? ratio, i'll have
to check on shaft dia. & oiling provisions/design. 8 bills from T&D don't sound bad if that's thecase, depending on what is included, the PP&R's have billet hold-downs,shaft,spacers etc. sothe extra $230 may involve those items....
You can grind clearance for the p-rods, but I don't think near enuff for a V-8 rocker,not
to mention moving the shaft that much isn't feasable or complimentary.As far as SB shaft
diameter, it shouldn't be too hard to hone al rockers up if they were an opt.

Sometimes, it's better to just bite the bullet and pay the freight... But, my case is a little different, in its "race-car only" requirements, I can get away with lots of stuff that would not work at all, on the street, such as my brutally-simple ignition system. I tried driving it on the street with that locked distributor-plate and no vacuum advance when I moved the car from my ex-partner's garage to mine, 35-miles away. It used 5 gallons of gas at 50mph on the hiway in that 35 miles. My limited math skills conclude that that's 7 miles per gallon, at a cruise, for a 2,700-pound car. That's just one facet of my "race-only" tune...

But, the rockers can be manually-oiled at the strip, which would not work on the street..... I have no idea what the welding will do to the oil slots that they use to lubricate for street-duty. So, I took the coward's way out and just examine everything every 5-minutes of run time... It's what you do when you don't have much money...:banghead: