high ratio rocker arms

BCOWANWHEELS

Well-known member
since classic inlines is all but gone guess I,ll try to find out what was the intended application for the 1.65 rocker arms hopefully adjustable also who could make the aluminum roller rockers Harland sharp ? also does anybody know the pushrod length with the cupped end and its application. my engine is a 4.1 250. although I,am new to ford 6,s I already miss c/I business
 
I,am working on some rocker assys. called my old Chrysler hemi rocker shaft rebuilder and he thinks he can fix us up with anything we might need. gonna talk more to him tomarrow so the ball is rolling. he also builds aluminum rockers for any engine . always good to talk to old friends. he kidded me youmust be desperate going from a fuel 392 to a 250 ford 6. we laughed....
 
That would be sweet. I'll definitely be excited to hear what he thinks
 
I have designed an extrusion die for some Slant 6 roller rockers, so making one for these small 6 rockers wouldn't be a problem. Just need a fairly consistent demand to pull the trigger on doing one for them.
 
everybody except those who rebuild total stock engines wants custom rockers. I don't want to step on anybodys toes as CHRIST would not be in it . but I want 1.65 rockers that are adjustable preferably irn or alum don't really matter also but I,ve brought serveral items into production for different applications for 3 decades. I,am retired now and really don't want to go thru this for several reasons but I,am gonna because I want a set for my engine. pushrods isn't a problem, hard chrome rocker shafts isn't a problem. theres gotta be a real close if not right on match to the rockers . example fe rockers,292-312 rockers etc. as far as cams if you,ve got a good core isky will regrind your to your spec,s and you,ll know your cam isn't china junk. that's my plan on it. I guess 255 pistons so I don't have to cut head or block down /or not as much.
bob

p/s always open to thoughts or suggestions and if anybody is going to buy this closed business out please contact me so I don't mess you up. ......
 
Yella Terra was the manufacturer of those I think.
You might have to look to the Aussies for them now.
 
Hi Guys count me in for a set of adjustable roller 1.65 rockers, I too am building a 250 for all out racing. Let us know. Yella Terra rockers are just too expensive. Thanks Randy
 
Hi Guys count me in for a set of adjustable roller 1.65 rockers, I too am building a 250 for all out racing. Let us know. Yella Terra rockers are just too expensive. Thanks Randy
 
Hi Guys count me in for a set of adjustable roller 1.65 rockers, I too am building a 250 for all out racing. Let us know. Yella Terra rockers are just too expensive. Thanks Randy
 
Hi Guys count me in for a set of adjustable roller 1.65 rockers, I too am building a 250 for all out racing. Let us know. Yella Terra rockers are just too expensive. Thanks Randy
 
Hi Guys count me in for a set of adjustable roller 1.65 rockers, I too am building a 250 for all out racing. Let us know. Yella Terra rockers are just too expensive. Thanks Randy
 
called my rocker guy and he asked if we could persue this after the new year starts so I agreed.. gotta go with the flow
 
What you want is full roller rockers the other at the fulcrum.
One drawback of the yella-terra.s are the size of the fastener that bolts them to the mounting bar.
A real plus would be 7/16" fasteners.
SI industries will make a longer valve to allow the use of 1.7" installed height valve springs, so valve lifts can exceed .525" valve lifts & allow valve springs to allow the higher & faster rate of lift, but still maintaining short duration to enhance low & mid-range power.
 
I,ve used si for all my valves for years-decades. I,am not going to persue anything but 1.6 or 1.65 preferably adjustable but non adj. might be the only route. we,ll see. I,ll keep everybody informed. possibly we could do a group order ?????????????? who knows. anything to bring cost to a minimum. I just want a set of rockers for my engine. all else is a plus
 
I'm sure you'll get enough responses to make it worth your while. And I know that with you background, you'll get good economies of scale.


I'd go for 1.73 or 1.80:1 if it were me. Its just advice, not manadatory. But it is based on 38 years of research which I started when I was seven. (I had a father with a 78 hp 138 six, and a 145 hp 225 six, and a grandad with a 165 hp 245 six. I got together all the info on the engines, and started a quest for I6 enlightenment).

I'd like to add that just recently, I found quite a number of mistakes in engine flow analysis, and some wrong details regards to what works for our engines, but basically I've been right for the wrong reasons on what works with the log head small sixes as a consequence.


Basically, the 1976-1987 cross flow and 1988-1998 Single over head cam 200/3.2 and 250/3.9-4.0 engine like 270 degree at lash and above cams with as much lift you can get in between the pistons and head. That's 530 to 560 thou safely. With proper induction (4-bbl or efi), you then get easy 265 hp as a 200/3.2, and 315 hp with a 250/3.9-4.0. Only these cams get any reasonable performance gain over the compromise less than 270 degree cams. Witn more aggressive cams in the over 300 degree range, power can go up to 300 and 350 hp respectively.


The less adept breathing of the non cross flow log head can use a 275 or greater cam with 470 to 490 thou lift, obviously limited by valve to piston contact, and they need it to give even 235 and 280 respectively for 3.126 and 3.91 stroke 200/250 engines(4-bbl or efi). With 310 degree cams, you get a flatline due to induction restrictions, but its possiable to get into the 265 to 315 hp range with a low peak flow head if you do some simple carb repositioning. .

At those durations, peak lifts, those 1.73 or 1.8:1 rockers show a good increase in off the seat lift rate, and really allow better hydraulic roller cams to be used as well. Biggest performance boosts come from proper induction, and the non cross flow can really flow really well if you can grind out the inlet runners, and remove the big bends that single carb instillations produce. There is so much scope for the non crossflow engine if the intake fuel distribution is taken care of.

The sawn off log intake flows of Fast64ranchero, JTturbo, and 67Straightsix have been matched by Paul Knott with his 280 hp 170 small log six. So 165 to 185 cfm at 28"H20 is enough to make well over 280 hp easily, and with the right intake mods, a 1.73:1 rocker ratio will do well for even a 200 six.

You can follow the normal process of copying the Australian practice, but the work Dave Bennett at Perfectune did it was to consolidate the engineering parts, so the 1.65:1 rocker is a Ford V8 part reworked for the non cross flow six. It uses GM Holden 186S pushrods, and a number of parts to make it all work.

As such, it is a compromise. When used on the FE, the same rockers dial in as a 1.73:1 rocker ratio roller.

From a purely simplistic angle, the design team that made the Falcon engine a 1.5:1 lever arm rocker could have just as easily made it 1.73:1 just like the 1958 FE (and later Boss 302/ Ford 335/ Big Block 385 engines).

That small six team was bascially the same team that designed the 1958 FE.

To make 1.65:1 in 2015 lookes a little short sighted when we are now aware of just how much the engine needs more lift.


The rocker shaft is unsupported for the exhaust valves, and could ideally use a drag race style FE style rocker solution.


There are 1.8 and 1.9 rockers as well, used in canted valve OHV V8 small block race engines.


And the valves could be made usefully longer (5.16" tall verses 4.78") to use modern conical valve springs.


The whole pre cross flow head is in need of work to drag it kicking and screamng into the 21st century.


And roller lifters are an easy inclusion with just a Mike1157 style block modification. The way Mike did it was to drill 2" holes, but you can fly cut a bunch of horizontal slots with much less impact on the block, and make space for the lifter ties or 5.0 EFI style spiders.


Traded off against the cost of an intake, an alloy head, and the carb limitations of one source of air fuel dispersal, the log head can save you a bunch. Proper 1.73:1 rocker arms, a roller cam, lifters, and the bare mimum to get it into the tight non cross flow block, a high rev kit will awaken the non cross flow.

Following the historical rules of an ex Ferrari Italian engineer who later did in line sixes after V12's, I've gotten the log head intake flowing the way it should with just 4-bbls of carburation.
 
Gotta keep it as simple as possible, the less custom parts the better. there are tons more small budjet people than high budjet people. yes a person could engineer all of this out but only a very small few could / would actually afford to buy it where as a modest setup would be more attractive and purchased by the masses. there is a extreamly limited market for hi-po parts these days.. jmo
bob
 
BCOWANWHEELS":2caf99ko said:
since classic inlines is all but gone guess I,ll try to find out what was the intended application for the 1.65 rocker arms hopefully adjustable also who could make the aluminum roller rockers Harland sharp ? also does anybody know the pushrod length with the cupped end and its application. my engine is a 4.1 250. although I,am new to ford 6,s I already miss c/I business

:banghead: The early 1980's had Perfectune make alloy extrusion rockers braded as Yella Terra. These Australian rocker arm use:-

1) a differernt lifter (302 Windsor/Cleveland hydraulic lifters), with
2) General Motors Holden 1968-1970 model year (Monaro/Kingswood/ToronaGTR) 186S pushrods.
3) The system uses a variation on the early adjustable valve gear.
4) Since its an extrusion, its not as strong as a traditional steel rocker arm can be, and there is evidence that roller tips are of no real benfit.

Look at Chevy's modern small block...they don't have roller tip rockers, but do have long rocker ratios.


If you wanna copy backward late 60's thinking, go for it.

For the cost, you could design proper 100% US components for a lot less, and get a 1.73:1 rocker ratio.



If you want to use early 80's tech, and late 60's parts on a 50's designed engine to beat all the work that Ford Australia overturned with a 1.73:1 rocker ratio 1976 cross flow, that's your business.

I'm telling you that on an engine that breaths as badly as the 250 does, you need every thousanths of rocker arm movment and duration.


In the case of removing 125 thou of lift by putting in a zero deck 8 cc dish 255 piston...that won't help you amke power.

I'd presonally use the hugh 1/8" piston short fall for more valve lift, and forget about ideal zero deck heads. Do you want a proper 560 thou potential valve lift with 1.73:1 rockers that needs only 325 lift at the lobe, or 490 thou lift that almost hits your pistons, and too much compression?



You need more lift, more duration, more piston to valve clearance, and a more constructive approach to building power. Ford in Australia was using 1.73;1 rocker ratio sixes in 1976, and longer conrods in 1998, and that's why a little 4 liter engine can shut down a good 5.0.


In 1969, little 245, 250 and 265 Hemi engines with 1.7:1 rocker ratios were taking out 302's and 351's for 11 years in sedan racing.
 
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