I figured for sure you'd come back with some .145 wall, double-taper, polished tool steel pushrods that cost like $600.

You got off way too easy.

 

Yeah, ha ha! Terry Manton could have upsold me some but he is a genuine person! He mentioned that I didn't need the tool steel option (if I remember correctly) unless I got to like 700# spring pressure. He was rattling off information and questions faster than I could process it!
I tried a rough check and did a comparison on my comp cam pushrod checker for overall length. I set it to between 10 1/3 - 10 1/2 turns which is what we averaged between intake and exhaust. I then locked it down at that length with electrical tape. I will still take it to a machine shop for proper measurement. With adding 0.040 preload I measured 7.39" by using two bolts stacked end to end with a nut that I adjusted to get exact length. I then measured the two bolts seperately with my 6" caliper. This roughly compares to the 7.36 using the comp checker. I will give you the final accurate result tomorrow!

 

What are your spring forces?

 

They are 150# close & 450# open I am almost positive from what TEA told me.
Comp Cams recommended 135# close & 400# open springs for my cam when I called their tech line.

 

Update - got the adj. pushrod measured at a local machine shop this morning.
The overall length ended up being 7.330".
When I add my 0.040" lifter preload that gives me 7.37" pushrods.

If I would have gone by the comp cam pushrod guidelines I would have ordered 7.36" with the same 0.040 preload.

I will be calling Manton this morning and placing my order!

 

See post 15.

It's not that one was wrong or right...it's just using a different form of measurement. If you ordered a Comp pushrod for example, 7.358" would be correct...Manton wants overall length, and 7.375" is correct for that. Either way you'd get the same length part.

 

at our level whats the big benefit in running a big fancy schmancy 3/8 pushrod vs the standard comp hardened .080 wall pushrods 7.550 length in my case

 

It's kinda like when you sit down at a restaurant, and order a glass of beer...the waitress asks if you want the 16oz, or the 24oz.
Does anyone ever order the 16oz?

Oh, pushrods. Yeah...you want them as stiff as possible. They do deflect in operation , and minimizing that deflection is good. Good for better valve control, good for high RPM stability, good for reducing valvetrain harmonics.

Adding stronger valvesprings, larger-heavier valves, increasing pushrod length, increasing RPMs, are all things that will cause a pushrod to deflect even more.

Of the various ways to combat deflection (stronger material, thicker wall, bigger diameter)...Increasing diameter (by far) makes the most difference.

There's nothing inherently "wrong" with your .080" wall 5/16" chromoly pushrods, they are a definite improvement over stock...but they are kinda like that 16 oz beer...pretty good, but not the best when you have the option to go bigger.

Simply put, run the biggest dia. pushrod you can fit, and enjoy a more stable valvetrain.

 

hmm...ill have my valvetrain out this weekend and im putting a fresh set of springs on...im going to check again my pushrod length with my comp checker...then I'll give TEA a call and see if the TFS 215s always had enough room for the 3/8 pushrod or this is a recent thing. Im running comp 850 16 lifters thats why my pushrods are so much longer...i like to see .040 of preload
how much were the 3/8 pushrods Verne?

 

TEA TFS heads made in the last 9 months or so were machined for bigger pushrods. The rods I got were about $10.75 each plus shipping.

 

The 7.37" Manton pushrods with 3/8" .095 wall and 5/16" ball ends are ordered and will be delivered on Friday!

 

Cool deal.

Like I said, hope to make it up there Sunday. (Assuming you'll be wrenching on it).

 

Hey have a good trip and don't drink too much beer at the cruise-in! I will let you know for sure what day(s) I am working on the car - may have a cookout on Sunday but if that happens I will wrench some on Monday.

 

damn...i bought mine like 14 month ago or so

 

previous to 9 months ago did they say what was the maximum dia pushrod you could run on a TFS 215?

 

I have not done this myself but the feedback I have gotten from several people is that Terry Manton's 11/32" pushrods have been working in most unmodified heads (unmodified for larger pushrods that is). While it doesn't get you to 3/8, by my calculations the bending stiffness increases by over 50% from a 5/16" 0.080" wall pushrod of the same length.

 

Here are some pictures comparing the 3/8" Manton pushrods to my stockers....

 

Nice looking part. Terry made me a special 11/32 OD with an over bored end so I could remove the ball end and adjust the length to make sure it would fit. His pushrods are beautiful.

 

measured mine today...kept getting different measurements on the intake and exhaust...not sure if its due to my large duration split (8 degrees) or what...lobes are same intake and exhaust LSL lobes 620 623 lift intake and exhaust...duration 235 243

heres the measurments i took with my checker 7.4875 intake at zero lash 7.500 exhaust at zero lash

bore of my TFS pushrod hole per my fancy measurment (stuck different size 1/4 inch drive sockets in till i got a snug fit then used the calipers) was .450
with a the following pushrods you get this clearance:
5/16=.3125 .450-.3125=.1375/2= .0688" clearance on either side of the pushrod assuming pushrod is centered in bore
11/32=.3438 .450-.3438=.1062/2=.0521 """""""""""""""""""""""""""""""""""""""" """""""""""""""""""""""
3/8=.375 .450-.375=.075/2=.0375................................. .......
yes i have the clearance assuming all is centered but we all know as a rocker works it pushes and pulls the pushrod away from and toward the valve as it works its motion

Im going to bet i only have room for a 11/32...

Talk with Terry "the man" Manton today....just the OD change of the 5/16 pushrod to a 11/32 increases strength by 50%...he only stocks 1 wall thickness of 11/32 rod and its .120 wall this increases strength by an additional 9-10% so if I go to a 11/32 manton 3 piece pushrod it will be approx 60% stronger than my current comp magnum 5/16" .080 wall chromoly pushrods

now if i could run a 3/8" you damn well better believe i would...its lighter than the 11/32 120 wall model due to only having a .080 wall yet 2 times stronger than the .080 wall 5/16 model

so as Y2Kvert puts it...i dont get my 16 oz glass of beer and i cant get my 24 oz....my motor should be satisfied with the 21oz glass of beer haha

now the question is what length should i go with

now i understand Manton wants overall length and this supposedly is different from gauge length...but when i measured roughly the 7.500 length i came up with by the gauge reading...i stood it up on end next to a scale and sure enough lined right up with the 7 1/2 inches
im thinking 11/32 7.540" .120 wall 3 piece pushrods this by my calcs should give me .0525 intake preload and .040 exhaust preload assuming measurements were correct...currently running comp magnums 7.550 (this offered 5/8 to 3/4 turn of preload, does that sound right then for my measurents?)

random question...if i compress a cylinder with air and it shoots it to BDC (all plugs are pulled and im changing valvesprings) which cly will be TDC easy access cylinders for pushrod measuremend would be 4, 6, 1, and 2 which cyls would have to be at BDC for those to be TDC

Thanks for the help guys...hope i have one stable *** valvetrain after this swap

 

Did you have a valve train issue with the 5/16"? Curious to know.

3/4 turn is (1.25 X 3/4)/25.4 X (2.7/1.7) = 0.058" per my calculations. 5/8 turn is 0.049".

Overall Length is approximately 0.017" shorter than gauge length. Do you have an 8" vernier?