I was a little concerned with the close proximity of the pushrod to the tube on my engine,
so I did some homework about pushrods.
Currently the engine has 3/8" straight 4130 pushrods, and after checking the lift with and without the heavy springs,
it seems there is enough flex to lose .035" of the lift.
So I have two problems: flex and interference. Problem is that to fix the flex problem will cause more interference.
The answer seems to be a tapered pushrod with better heat treatment.
This is nothing new, as I have used the Autocraft taper pushrods before
but not with these springs(620lbs) and rocker ratio(1.6).
Also the Autocraft pushrods are only 5/16" on each end,
and in the length I want, the don't begin their taper immediately.
And yes, you can buy some pushrods that will work, but you know me. I can make them exactly how I want them, and use the tips that I have already.
The material is 1/2" 4130 chrome moly tube with a .156" wall thickness...very strong.
Apparently, pushrod stiffness is more important than the weight gain. Some say that pushrod weight, and any weight on the lifter side of the valve train, is not as important to valve control, as weight on the valve and retainer side of the rocker arm.
[ Edited on 31-3-2006 by dangerous ]
[ Edited on 20-11-2006 by dangerous ]
dangerous ·
After hacksawing the material about 1mm too long, I can face it to length in the lathe, and drill the ends
to give 4 thou interference on the tips.
The rocker end will have a ball end for adjuster clearance, but the lifter end only needs a radius end.
The ball type end is an auto craft part, while the fat radius end is out of a very cheap 3/8" pushrod that I found at a swap meet.
But before the ends are fitted I will taper turn the outside diameter to provide pushrod tube clearance.
dangerous ·
In this case, the lathe tailstock was adjusted off centre by.100" to get the taper I need.
I have roughed it down to within 1/2mm of its finished size before heat treatment,
so that I can check the fit in the engine. I fitted the tips to this one, and checked the fit is OK.
So now I can send it to Rene in Adelaide (Volksy hell-guy) for hardening to increase the material's stiffness.
The finished size will be done when I get them back, and will be 8.5mm on the rocker end, 12mm in the middle,
and 10mm on the lifter end.
Rene will harden them to 42 rockwell C, which is about 180 000 psi tensile strength. He is the best for this stuff.
Only the tubing is heat treated, the tips are already hard, and will be fitted when the tubes come back.
dangerous ·
How is this?
[ Edited on 27-1-2006 by dangerous ]
A 1200 is slow ·
They are some nice pushrods!!
Would you consider making some for other people, and if so , how much$
dangerous ·
The reality about a project like this is that it is only cost effective if you make them your self.
To be viable as a money maker you have to remember that the tubing is just under $200.
Then you have the cost of the ends(?).
Heat treatment I would guess at $100,
and of course labour to make them.
Suddenly you have a set of pushrods that cost about $700!
The best of the pushrods you can buy for Volksies, like Berg or Autocraft are less than half this.
Most engines can use the basic Scat or Berg 80000psi deals for under $150 (3/8" chrome moly).
BTW 1200's are cool. Mine ran 20.95 et @ 62mph.
[ Edited on 28-1-2006 by dangerous ]
A 1200 is slow ·
Yes I know they would be expensive,like you said, the material is not cheap then heat treating and labour....it does add up to a lot.
But a set of Manton(?) tapered ones like the ones you have made would not be cheap either.
Your ones look a lot stronger than anything else on the market for volksies, and personaly I dont trust chinese quality "chrome-moly" that all the other ones are made of.
Yes 1200's are cool!..........and slow too!
dangerous ·
This one Simon!
humpty ·
Cheers Dave..... Thats some good looking work there... I can appreciate the effort your putting in here.... Awesome stuff!
lliszabailey ·
dangerous wrote:I was a little concerned with the close proximity of the pushrod to the tube on my engine,
so I did some homework about pushrods.
Currently the engine has 3/8" straight 4130 pushrods, and after checking the lift with and without the heavy springs,
it seems there is enough flex to lose .035" of the lift.
So I have two problems: flex and interference. Problem is that to fix the flex problem will cause more interference.
The answer seems to be a tapered pushrod with better heat treatment.
This is nothing new, as I have used the Autocraft taper pushrods before
but not with these springs(590lbs) and rocker ratio(1.6).
Also the Autocraft pushrods are only 5/16" on each end,
and in the length I want, the don't begin their taper immediately.
And yes, you can buy some pushrods that will work, but you know me. I can make them exactly how I want them, and use the tips that I have already.
The material is 1/2" 4130 chrome moly tube with a .156" wall thickness...very strong.
Apparently, pushrod stiffness is more important than the weight gain. Some say that pushrod weight, and any weight on the lifter side of the valve train, is not as important to valve control, as weight on the valve and retainer side of the rocker arm.
[ Edited on 31-3-2006 by dangerous ]
[ Edited on 20-11-2006 by dangerous ]
Hi just wanna ask about the rocker arm you told what is the brand you are using on that part? Is it OEM? I'm planning to buy a Omix Rocker Arm but I'm not sure if that brand is a good quality so that i will gonna spend my money on some useless parts
BeetleBug ·
Nice,
Over here we`re buying HD ALU pushrods from either JPM or Skinne Racing. They weigh 65gr (with ends) and are tested with K800`s and "old school, crazy high spring pressures"
The best thing about them apart from low weigh is of course that you do not need to adjust you valve lash every now and then and of course the silence.
Turbo54 ·
How much are they?
T54
dangerous ·
Just so people are aware, this post was started in 2006.
My new pushrods will be a lot thicker than those because of the 1.7 rocker ratio and 1000lb springs.
Just did an initial check with light test springs and there is .762" lift
I think Aluminium pushrods are a great option for a lot of applications,
just not mine.
BeetleBug ·
Dangerous;
What are you`re goals with you`re new engine? HP and ccm? Lift is very close to 20mm - big valve - high spring ratios - big results 🙂
dangerous ·
Hi BeetleBug
engine is 2699cc with 82 stroke and 102.36mm bore.
Aiming for mid tens eventually.
Best so far weighing 805kg is 10.93@122.
using Pauter heads.
New heads are CD that I have been working on and off for 2 years
dragvw2180 ·
!000 lb springs !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! wow !!!!
Dave why so much if you are going to run titanium valves ? Mike
dangerous ·
Hi Mike,
I dont think I need that much,
but even now with 620lbs and .690" there are small signs that i could do with a little more pressure.
When ordering my valves and springs,
Roger crawford said this is the way to go.
It is a sort of compounding issue actually.
When stepping up from the 1.6 to 1.7 rockers,
the extra spring required, is amplified back onto the pushrod,(1.7x),
and so this needs stiffer pushrods.
Stiffer pushrods mean heavier pushrods,
...which need more spring.
dragvw2180 ·
Hey Dave,
I know that everything you do is cutting edge and I really enjoy reading of your progress, you are a very open person and willing to share your knowlege with us all , thanks . How much airflow will you gain by lifting more than 25% of the valve size or is it that you are trying to keep it flowing at your best lift for a longer duration by over lifting the valve ? The reason I ask is that when I flowbenched my heads they did not gain much airflow beyond 25% of the valve head size. I know your heads are WAY better than mine were and you know what and why you do everything. I just like to learn, Mike
dangerous ·
Hi Mike, most of the heads I have done keep flowing more air the higher you lift the valve.
It normally levels out around the .700 mark but still climbs a little.
This particular time I have changed the seat angle , which supposedly allows mor flow in the +.600 area,
so it will be interesting to see what the flow bench says.
Even if the flow levels out, there is still an advantage, because the valve will spend more time at the higher flow numbers.
Mind you, if the engine is too small, or can not see the RPM needed to make use of the additional air flow it may just lose performance.
The only head that I saw loose flow at higher lift was a Ford 351 cleavland.
but once the seat was sunk into the chamber so as to have it about .060" wide top 30 degree,
it made a night and day difference.
dragvw2180 ·
The flowbench I used was a Superflow 110 when I did my Superflow 48x40 heads, but I am getting older and more senile so I probably remember it wrong ,hhahahaha
dangerous ·
New material has arrived!
vlad01 ·
just whack them straight in Dave 😂 they'll fit perfect.
dangerous ·
Sides ·
Holy cr@p... that's huge !!!
(and a little voice in the back of my mind goes "heh... that's what she said"... 😉 )
dangerous ·
Just got them back from hardening,(Thanks rene'!),
and fitted the tips and polished the outside.
Red arrow is 1/2" and yellow is 3/4".
66brm ·
How do you go with pushrod tube clearance with those? Looks like they would almost fill the tube restricting return oil flow.
dangerous ·
Pushrod tubes are 32mm/27mm with 25 inside....heaps of room for drain back.
pete wood ·
They look awesome. 👍
Got 2 questions...
1. how much do they weigh compared to the usual hipo pushrod?
2. if they don't bend, what else will break?
dangerous ·
pete wood wrote:They look awesome. 👍
Got 2 questions...
1. how much do they weigh compared to the usual hipo pushrod?
2. if they don't bend, what else will break?
1. 350 grams (not sure what weak pushrods weigh for comparison?)
2. nothing I hope!
STIDUB ·
#2 - best answer ever 👍
im looong overdue for a visit to yours db, have stuff sitting here waiting for a chance to get down there, free friday?
dangerous ·
yeah Friday OK, ring first, you know the drill!
dangerous ·
pete wood wrote:They look awesome. 👍
Got 2 questions...
1. how much do they weigh compared to the usual hipo pushrod?
2. if they don't bend, what else will break?
I just weighed some other pushrods for comparison.
Remembering that
mine are 350g,
stock is 39 grams,
Thin wall 3/8" cromoly 63g,
Thick wall 3/8" 85g,
Autocraft tapered 72g,
CB Manton tapered 107g.
So mine are over 3 times the weight,
thus the reason for the 1000lbs springs.
mactaylor ·
any way of taking more weight out of them dave?
HappyDaze ·
Did you weigh the pushrods FULL OF OIL? I tried it [many years ago], and was surprised at the results! Because of the weight of the oil, I plugged the holes in the [tapered chrome-moly] pushrods, and oiled the [needle roller] rockers before each race. The oil-surge on corners helped a bit, as it was a circuit car. Never had a problem,
dangerous ·
mactaylor wrote:any way of taking more weight out of them dave?
I am sure I can turn the large diameter down a little,
but for now I will see how they hold up,
and influence the rest of the valve train.
dangerous ·
HappyDaze wrote:Did you weigh the pushrods FULL OF OIL? I tried it [many years ago], and was surprised at the results! Because of the weight of the oil, I plugged the holes in the [tapered chrome-moly] pushrods, and oiled the [needle roller] rockers before each race. The oil-surge on corners helped a bit, as it was a circuit car. Never had a problem,
I normall plug all the pushrods
and just have one exhaust with a 1mm restricter.
This is to supply oil to the valve springs for much needed cooling.(according to the spring manufacturers)
BeetleBug ·
How do you plan to keep your heads where they should be with that spring pressure?
ian.mezz ·
yeah is it just me or do they look toooooo biggggg 😊
If a rocker breaks the push rods will shoot out like a small missile.😊🤪😊
or the extra weight and load will loose HP 🥲
dangerous ·
ian.mezz wrote:yeah is it just me or do they look toooooo biggggg 😊
If a rocker breaks the push rods will shoot out like a small missile.😊🤪😊
or the extra weight and load will loose HP 🥲
Yes that is correct.😂
Some times you have to sacrifice some things to get reliable goals.
Like money , you have to sacrifice some to make some more.
When I find an aluminium grade that can handle around 600lbs times the rocker ratio of 1.7(1020lbs),
I will be able to run a lighter spring,
and still run the lift(.750") and rpm that I need.
But for now,
these pushrods should handle the 1700lbs that the rocker will transfer back to the pushrod.
HappyDaze ·
ian.mezz wrote:yeah is it just me or do they look toooooo biggggg 😊
If a rocker breaks the push rods will shoot out like a small missile.
Hey, he's got a name to live up to❗
Dangerous, nothing to worry about, provided that your Public Liability insurance is adequate.😂
BeetleBug ·
There are many ways to skin a cat and I believe 350 NA hp is possible with our engines with the right combination. Also without having to take the engine apart after every run.
It will be interesting to see the end results.
Best rgs
BB
mactaylor ·
what about two piece pushrods double taper?
BeetleBug ·
Or what a about a cam design that makes the job easier? With a incorrect cam design you can use the strongest spring in the world... and still experience problems.
For example: a comparison between Pauter vn011(left) Raptor (middle) and Shawn Geers' wildest grind (right) Which one will make the job easier you think?
cnfabo ·
hhmmmm, middle?????
66brm ·
I'm guessin either geers or pauter, the ramps on the raptor look almost parallel, meaning high valve speed and potential for less control
cnfabo ·
66brm wrote:I'm guessin either geers or pauter, the ramps on the raptor look almost parallel, meaning high valve speed and potential for less control
🤪 andrew , you have not read much about johanes have you...start searching...:🤓
Craig Torrens ·
dangerous wrote:
pete wood wrote:They look awesome. 👍
Got 2 questions...
1. how much do they weigh compared to the usual hipo pushrod?
2. if they don't bend, what else will break?
I just weighed some other pushrods for comparison.
Remembering that
mine are 350g,
Wow...my steak I had for dinner tonight weighs the same as your pushrod.......they certainly are 'meaty' 😂😂
BeetleBug ·
All the cams was considered for a 2.9l NA street/race engine with MS230 heads that are slightly modified and flows 320cfm in 25" of water with manifolds. Valves are 49.6mm (intake) and 38.6mm. The Raptor will utilize the full potential of the heads. At 8mm lift they flow 205hp, 10mm = 230hp, 12mm = 268hp. Less spring pressure = more power, less heat and more rpms. Sorry for bringing this excellent thread from the topic.
pete wood ·
^ drool.
Johanes, if I ever get to put together a serious ACVW motor, it will be full of your parts. 😏
BeetleBug ·
OBS OBS:
Please note that I`m not Johannes and I`m not involved in his company JPM (Johannes Persson Motorsport) in any way. I am however a firm believer in what he is doing and making and I`m using his products in my own builds.
Best rgs
BB
dragvw2180 ·
The JPM heads are a really nice update of the CE or Superflow heads and for the street I cannot think of a nicer head, but for what Dave is doing I think he has superior heads. On his engine cooling is not an important factor so the cooling fins they added are not a benifit. Also I would question the stiffness of the casting when bored out for the 101 mm cylinders and the compression , let alone adding 6 studs to them. In order to get the airflow Dave is looking for would require alot of welding and reshaping of the ports also. After reading all the posts Dave has written and enjoying them, I know he put alot of thought into everything he does. The only thing I am suprised about is that he has not built his own billet heads yet, but these are close. Mike
LIFE IN THE LOW LANE ·
Don't put naughty thoughts in his head lol
reub ·
HAPPY BIRTHDAY to DAVE❗
Dak-A-Tak ·
Are Facebook , working on your heads will be a fine Birthday ( have good-one mate) . Doing a wally with that facebook pic of
yourself 🙅