Ok...This ought to stir the pot...

[Krooser]

I've been around this stuff a long time. I hung around with my brothers hot rod hoodlums around 1954. We searched junkyards for cars and parts. I got introuble for thinking all those old cars in the yards were "junk" and I "removed" about a dozen shift knobs from 30's/40's cars until the yard boss made me aware that I was stealing his stuff...ouch !

Anywho...

I am thinking it's time to do a pre-assemble on the top end of my race motor so I can order some pushrods. Switching from Mopar adjustables to the T&D's I got with the engine.

I remember a time, not so long ago, where we NEVER measured pushrods on our stock rebuilds or dirt track engines save for the ones where we swapped non adjustables for something else. Never. Ford FE, Cleveland, Mopar, Studebaker even SBC ( I shudder to use that term).

We may have shaved the heads, decked the block and we used the same pushrods even if we had non adjustable rockers. The juice lifters took up the distance. Today that's blasphemy... you would think taking .020 off the heads and deck was a mortal sin (if you believe in that sort of thing).

I do... but I am not afraid my 3rd grade nun, Sister Mary Adolf Hitler, will crawl out of her grave and swat my behind with her 2x6 cleverly disguised as a yardstick. I don't think she cares.

So I figger many these new pushrods that are sold today by the advertising agencies and publicity departments of of Manton, Smith Bros (I DO like their coughdrops), and all the myriad cam grinders that also sell pushrods.

It's kinda like someone using scare tactics to encourage an entire nation (in this case the Gearhead Nation) to use/buy something that may not be needed...huh. I know that is impossible...

OK I have said my piece. Now back to my search for some NOS Duralube teflon engine treatment to go along with the new Tornado supercharger for my air intake.

 

[Professor Fate]

I remember very few custom pushrod mfr.s back in the day-like you say, it wasn't something we worried about. And when I did need a different length pushrod for those 273 rockers, we just scavenged some slant 6 pushrods, knocked the end off, cut them to length, and pressed the end back in... I think they were larger diameter, too... Instant heavy duty, custom length, and basically free.

 

[Krooser]

I'm not saying it's not a good idea...in my case I need a 3/8" pushrod with a little thicker wall for the 400#-ish. open pressure springs I may use.

 

[j par]

I'm not saying it's not a good idea...in my case I need a 3/8" pushrod with a little thicker wall for the 400#-ish. open pressure springs I may use.

What about this new mortal sin of not correcting your rocker arm geometry...
If you don't call B3 racing and have this done your stuff is junk...

 

[mopar head]

About 25 yrs ago I bought a set of milled 390 heads off a machinist, He told me I should check pushrod length. He probably seen my eyes glaze over, didn't have a clue back then, pre www for me.
On decell. pop pop pop pop, I fixed that by always putting it in neutral and using brakes.
Ran strong so I said F it. I`m edge e ated now

 

[Jeremiah (jd)]

It really depends on the lifters and how much preload they require.

There is a time and place for new pushrods.

Trend Performance - About the Company and Founder Bob Fox

It all depends on how things go together. Sometimes you need longer or shorter pushrods. For instance, roller lifters are taller than solids. They also have require more spring pressure. The solid for my black '66 Charger calls for 900 over the nose and 300 on the seat.

If you put together an engine that takes advantage of a t&d setup and you have valve spring pressures that handle stock pushrods t&d rockers are overkill for the application. Solution - buy roller lifters, solid roller cam and....new pushrods! : D

If you are using a juice cam you might find the adjuster out there a ways if the lifters require .045 of preload to quiet things down.

From www.compcams.com

Rocker Arm Adjustment/Lifter Preload
All but a few Chrysler engines were equipped at the factory with non-adjustable rocker arms. Anytime a solid lifter camshaft (either roller or flat tappet) is used, you must also use the adjustable rocker arms and appropriate pushrods.

When installing any high performance hydraulic camshaft, the lifter preload is something which must be considered. Too little preload will result in a noisy valve train, and too much preload will result in tight valves and a poor running engine. Either condition can result in less than expected performance or engine failure. After the cam, lifters and rocker arms are installed and prior to installing the intake manifold, you must check the plunger depression in the lifter. With the cam on the base circle (valve closed) the plunger in the lifter should be depressed .040”-.060”. With nonadjustable rocker arms, you must change pushrod lengths to obtain proper lifter preload. This is a delicate and time consuming process, so if you have any questions, contact the CAM HELP® line at 1-800-999-0853.

 

[Krooser]

What about this new mortal sin of not correcting your rocker arm geometry...
If you don't call B3 racing and have this done your stuff is junk...

Don't need B3... the T&D rockers use shims under the stands to do the adjusting. Simple.

I too radical they will build offset stands.

 

[Krooser]

It really depends on the lifters and how much preload they require.

There is a time and place for new pushrods.

Trend Performance - About the Company and Founder Bob Fox

It all depends on how things go together. Sometimes you need longer or shorter pushrods. For instance, roller lifters are taller than solids. They also have require more spring pressure. The solid for my black '66 Charger calls for 900 over the nose and 300 on the seat.

If you put together an engine that takes advantage of a t&d setup and you have valve spring pressures that handle stock pushrods t&d rockers are overkill for the application. Solution - buy roller lifters, solid roller cam and....new pushrods! : D

If you are using a juice cam you might find the adjuster out there a ways if the lifters require .045 of preload to quiet things down.

From www.compcams.com

Rocker Arm Adjustment/Lifter Preload
All but a few Chrysler engines were equipped at the factory with non-adjustable rocker arms. Anytime a solid lifter camshaft (either roller or flat tappet) is used, you must also use the adjustable rocker arms and appropriate pushrods.

When installing any high performance hydraulic camshaft, the lifter preload is something which must be considered. Too little preload will result in a noisy valve train, and too much preload will result in tight valves and a poor running engine. Either condition can result in less than expected performance or engine failure. After the cam, lifters and rocker arms are installed and prior to installing the intake manifold, you must check the plunger depression in the lifter. With the cam on the base circle (valve closed) the plunger in the lifter should be depressed .040”-.060”. With nonadjustable rocker arms, you must change pushrod lengths to obtain proper lifter preload. This is a delicate and time consuming process, so if you have any questions, contact the CAM HELP® line at 1-800-999-0853.

Can't use roller lifters with the weight I'm running. I get a small weight break with iron heads and flat tappets. We have a wide variety of engines styles from the 600 HP-ish WISSOTA style mod engine I run to a 360" spec motor to 900 HP 11 degree 410" open motors costing $40,000 and up.

I don't know of any rocker arm I would trust besides T&D, Jesel or maybe Crower running 425lbs. over the nose for 50 laps on a big half mile @ 72-7500 rpm. The Mopar rockers that were on it before worked great at 6 grand...

 

[12many]

What about this new mortal sin of not correcting your rocker arm geometry...
If you don't call B3 racing and have this done your stuff is junk...

I agree that there are some who would contend your stuff is junk if you didn’t correct your geometry. But, I look at it as optimizing things. If correcting your geometry was free or a no cost process, took less calculations, who wouldn’t do it? In many cases I’m thinking there are those who are thrifty or miserly when it comes to doing or buying into some things? If it was free, cheap and easy to correct I bet it’d be a different story?

 

[j par]

I agree that there are some who would contend your stuff is junk if you didn’t correct your geometry. But, I look at it as optimizing things. If correcting your geometry was free or a no cost process, took less calculations, who wouldn’t do it? In many cases I’m thinking there are those who are thrifty or miserly when it comes to doing or buying into some things? If it was free, cheap and easy to correct I bet it’d be a different story?

Without question I 100% agree that optimizing your valve train geometry is going to help. I myself opted away from some roller rockers I have to some 273 rockers because the rollers were trying to roll off the end of the valve stem. Now do I want to stack up offset shims or unbolt and disassemble my heads to have them machined? No not really for a daily driver. If it was a drag race effort and not just a bracket car that needed consistency I would be all over getting my geometry maximized...
You know as well as I do that if you don't do things or buy things according to the highly opinionated gurus out here that your stuff is junk. Of course it's only junk in the world of Internet... In the real world nobody calls your stuff junk...

 

[Sterling]

I learned about pushrods early, the first 360 I built with a roller cam. I had a set of 3/8 pushrods laying around that seemed to work pretty good with the Harland Sharp rockers. The first hard pass at the drag strip started popping at the top of first gear. Shut it off, towed back to the pits. Check it out and find the pushrods bent like pretzels. Had to remove the intake and break them to get them out of the heads

 

[Jeremiah (jd)]

Can't use roller lifters with the weight I'm running. I get a small weight break with iron heads and flat tappets. We have a wide variety of engines styles from the 600 HP-ish WISSOTA style mod engine I run to a 360" spec motor to 900 HP 11 degree 410" open motors costing $40,000 and up.

I don't know of any rocker arm I would trust besides T&D, Jesel or maybe Crower running 425lbs. over the nose for 50 laps on a big half mile @ 72-7500 rpm. The Mopar rockers that were on it before worked great at 6 grand...

What is weight break and what class/type of car is this? Wegner Automotive Research in Markesan, WI would be my go to for something like that. Very talented and racer friendly shop.

If you can't run a roller I assume you cannot run Ti valves?

I agree on your choice of rocker arms. Failures occur on an endurance engine that you will never see on a drag engine.

 

[gregsdart]

If I read your post right you race roundly round and run engines restricted to flat tappet cams? Reason for proper geometry- to get the last horsepower you can out of the motor and also be able to rev past the power peak by a bunch so you can run a deeper gear for a harder charge coming off the corner? Also if you run a juice cam there is a measurable difference in different oils of the same weight. David Vizzard has talked about this, and did some testing of oils with different additives that worked better. I only run solid rollercams, so I don't have any info to pass along. But wouldn't it be nice if a guy found another 500 stable rpm than before , so you could run about 8 percent more rear gear? That 8 percent I believe would be a double winner. 8 percent more power multiplication PLUS an 8 percent rpm jump coming off the corner, which puts you up into more horsepower to boot.

 

[Dartswinger70]

I've been around this stuff a long time. I hung around with my brothers hot rod hoodlums around 1954. We searched junkyards for cars and parts. I got introuble for thinking all those old cars in the yards were "junk" and I "removed" about a dozen shift knobs from 30's/40's cars until the yard boss made me aware that I was stealing his stuff...ouch !

Anywho...

I am thinking it's time to do a pre-assemble on the top end of my race motor so I can order some pushrods. Switching from Mopar adjustables to the T&D's I got with the engine.

I remember a time, not so long ago, where we NEVER measured pushrods on our stock rebuilds or dirt track engines save for the ones where we swapped non adjustables for something else. Never. Ford FE, Cleveland, Mopar, Studebaker even SBC ( I shudder to use that term).

We may have shaved the heads, decked the block and we used the same pushrods even if we had non adjustable rockers. The juice lifters took up the distance. Today that's blasphemy... you would think taking .020 off the heads and deck was a mortal sin (if you believe in that sort of thing).

I do... but I am not afraid my 3rd grade nun, Sister Mary Adolf Hitler, will crawl out of her grave and swat my behind with her 2x6 cleverly disguised as a yardstick. I don't think she cares.

So I figger many these new pushrods that are sold today by the advertising agencies and publicity departments of of Manton, Smith Bros (I DO like their coughdrops), and all the myriad cam grinders that also sell pushrods.

It's kinda like someone using scare tactics to encourage an entire nation (in this case the Gearhead Nation) to use/buy something that may not be needed...huh. I know that is impossible...

OK I have said my piece. Now back to my search for some NOS Duralube teflon engine treatment to go along with the new Tornado supercharger for my air intake.

Woulda been cool to go through yards in the 50s,hell i enjoyed it in the 80s and 90s LOL! last time I saw an a body in a yard was 16 years ago or so...now days i watch oold movies to get a gist of what it was like back then Graffitti two lane black top etc. Ill watch movies and just check the cars out in the background. Its strange to me to see the huge boat american cars,with a few datsuns and volkswagens that were around in the early 70s...i was a kid then and i remember tose days buyt i was in elemantary school.

 

[jobrated_man]

i just stick with the flatheads, so don't worry about push-rods. For Pete's sake.

 

[CRUZE 418]

OK, what are T D's?

 

[TT5.9mag]

I think of it like this, my engine needs pushrods, my engine needs a certain length pushrod regardless of lifter type, my engine needs a correct length pushrod. Measure for pushrod length. That’s all.
@CRUZE 418 T&D is a rocker arm manufacturer that makes some very nice high end stuff.

 

[S'cuder]

OK, what are T D's?

T&D Machine Products :: Shaft Mount Rocker Arms Systems (tdmach.com)

 

[nckennyb]

I had a Racer Brown STX21 in a 340 I had in my Duster back in the late 70s which was a flat tappet solid lift cam. It had 0.560" lift but I don't remember the spring pressures. I had rocker arms and pushrods from a 273 in it and never even thought of rocker arm geometry back then. Everything held up to 7000 rpm launches and shifts although I did bend a pushrod when I blew a gear once. I was able to keep moving it up in the hole and applying pressure to get it bent back straight enough to get out without removing the intake. I put a stock replacement TRW pushrod in it's place and it was off to the races again with no problems. Fun days going fast but probably could have gone faster having everything optimized.

 

[K.O. SWINGER]

I had a Racer Brown STX21 in a 340 I had in my Duster back in the late 70s which was a flat tappet solid lift cam. It had 0.560" lift but I don't remember the spring pressures. I had rocker arms and pushrods from a 273 in it and never even thought of rocker arm geometry back then. Everything held up to 7000 rpm launches and shifts although I did bend a pushrod when I blew a gear once. I was able to keep moving it up in the hole and applying pressure to get it bent back straight enough to get out without removing the intake. I put a stock replacement TRW pushrod in it's place and it was off to the races again with no problems. Fun days going fast but probably could have gone faster having everything optimized.

Yes I'm on this vein I just run comp. Magnum push rods and rocker arms that are equivalent to Crane roller golds and shift my 340 at 6500 + a lot and a few miss shifts have put me in God knows how many RPM before my rev limiter days. Never a problem. I can't see the purpose of over 350 lb of open pressure if you're only turn 6,000 RPMs it seems you're over-sprung maybe?my theory is used just enough spring to control the valves and change them more frequently if needed. Oh yeah rev limiter setat 7100 RPMs

 

[Krooser]

What is weight break and what class/type of car is this? Wegner Automotive Research in Markesan, WI would be my go to for something like that. Very talented and racer friendly shop.

If you can't run a roller I assume you cannot run Ti valves?

I agree on your choice of rocker arms. Failures occur on an endurance engine that you will never see on a drag engine.

They use several different engine packages.

I'm running the IMCA modified engine pkg in a dirt late model. Iron block and heads, flat tappet cam...not much else for restrictions. Get a 50# weight break. Not much but it is something.

My engine was in mod thats why I'm using that engine package.

The competition use everything from a 360" spec package to 410" unlimited iron block engines making 850-900HP. The big horses rule. I' m there to compete as best I can before I become worm food.

 

[jacko241]

Back in the '90s I was running late models first on dirt, then asphalt. I put together engines with World Products pre-assembled heads, cast pistons, solid lifter cam, Speedway stock length pushrods and Crane gold roller rockers.
No optimization of geometry, just bolted it together and raced. Turned the engines to 7000 rpm night after night, never broke a valve spring, never bent a pushrod. One engine had 44 features on it before it finally broke a piston.