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Discussion Starter · #1 ·
Finally measured out the length pushrods I need and Id just like to get your opinion.

Motor is a Ford 302 1971 block which has been decked to 8.200".
Engine has Edelbrock RPM heads and cam with KB115 pistons and crane energizer roller rockers. The original pushrods are around 6.905".

Using comp cams 7702 adjustable pushrod (6.800" standard closed length) I assembled the valve train and positioned the roller travel over the center of the valve stem and get the smallest travel. The travel is about a 0.700" - 0.750" path when the engine was turned through a full cycle. To obtain this tip pattern I wound the pushrod out 4 turns = .200". Therefore I figure my pushrods should be 7.021", thats 7.00" measured + .030" preload minus the 0.009" difference between the checking lifter I used and my actual edel lifters.

So does this sound right!! Ive decked the block, added aftermarket heads and rockers and the required pushrods are longer than the original!

Cheers!

Andy
 

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Discussion Starter · #2 ·
Nobody got any opinion?
 

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What is the total overall measurement of your adjustable pushrod? I have never heard of anyone adding a preload amount before so I would probably use the 7.000" (or 7.050" pushrod.)
 

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Discussion Starter · #4 ·
Hi Dennis,
Measured length of the checking rod is 7.000" (6.800" plus 4 turns at 0.050" a turn {0.200"})

Im adding the 0.030" as Ive used a solid lifter to check geometry but am using hydraulic lifters in the final install, hence I need to added 0.030" to the overall length to allow for the preload I will apply when setting the valve train up.

Hows that?

Many thanks

Andy
 

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On 2006-04-18 12:37, asr427 wrote:
Hi Dennis,
Measured length of the checking rod is 7.000" (6.800" plus 4 turns at 0.050" a turn {0.200"})

Im adding the 0.030" as Ive used a solid lifter to check geometry but am using hydraulic lifters in the final install, hence I need to added 0.030" to the overall length to allow for the preload I will apply when setting the valve train up.

Hows that?

Many thanks

Andy
I have never used the tool that you have, and so I was mostly questioning its accuracy. (I make my own checking pushrod and measure its overall length after determining the best pattern.)

Again, you should be fine with either a 7.00" or 7.05" pushrod, (which is a typical range.)
 

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You need to recheck your setup before you order pushrods. The roller should be at the top of the valve tip at rest (or the base circle of the cam)
Heres the best info Ive found on the subject
http://www.compcams.com/technical/Catalogs/106-07/264.pdf
and this one.
http://www.compcams.com/technical/Catalogs/106-07/265.pdf
Good luck!

You need Acrobat reader to read this. Its free.

_________________
71 Pinto,5.0 Roller block,B303,1.7 Rockers,Crane beehives'68 302 portednpolished heads. Cut n re-welded,coated Must II headers,Rpm Airgap,Holley 570,Msd dist steel gear,Crane HI6
"The MONEY PIT"

<font size=-1>[ This Message was edited by: 71hotrodpinto on 4/19/06 9:38am ]</font>

<font size=-1>[ This Message was edited by: 71hotrodpinto on 4/19/06 9:39am ]</font>
 

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Discussion Starter · #7 ·
Cheers, thats pretty much what Ive got as the roller tip starts intake side on the base and then moves over the centre of the tip to exhaust side at full lift. To be honest it is slighlty more towards the intake side throughout but Im happy that the geometry is now good. Ill rig it up again and take a picture to show the wear pattern.

Cheers
 

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Although I've never checked valvetrain geometry, I always though the method was that the roller tip should be barely towards the intake side at zero-lift, then barely towards the exhaust side at mid-lift, and move back towards the intake side (but be close to center) at max-lift (so in the diagram in that PDF file, it would be 1-3-2 for zero-mid-max lift). This always made sense to me, because it meant that the angle between valve centerline and rocker tip to pivot centerline would be a perfect 90* angle at mid-lift, allowing for near perfect tangential force to be applied to the valve tip. I don't remember where I heard/read that, seems like it was from someone on the board here, but I'd take Comp Cams' recommendation over hearsay, so I guess I heard wrong.
 

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Discussion Starter · #9 ·
Finally managed to get some pics taken.

Pic 1 is with 6.8000" rod and Pic2 is with 7.000" rod.

I think the 7.000" rod looks the best, do you agree?





Cheers

Andy
 

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Pic 2 looks centered and narrow--that's really good.

Is this pattern after rolling the crank over a couple of times?

Be sure to do the exhaust too as sometimes there is a difference in valve length.
 

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Pic 2 looks great.Here's a good article on checking valve train geometry http://circletrack.com/techarticles/4635/ (click on the pictures for closeups)

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1968 mustang 306,stock ported heads,650 Holley DP,weiand Xcellerator intake, Comp cams Magnum 292,[email protected] and 518L,heddman headers,4speed with a 4.11 detroit locker.13.69 at 101 mph.

<font size=-1>[ This Message was edited by: frdnut on 4/22/06 7:00am ]</font>

<font size=-1>[ This Message was edited by: frdnut on 4/22/06 7:01am ]</font>
 

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Discussion Starter · #12 ·
Thanks Guys, only 1 rotation done so Ill check again after 2 rotations and Ill check the exhaust side as well though I remember it being the same when I checked last time, no photo though for the records.
 

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Hey guys, I'm about to go through this proccess also and I have one other question. I am using hydrolic lifters and I do not have a solid lifter to use during the checking proccess. How do you keep the lifter from compressing while you are turning the motor over? If you charge it with oil, will it hold its height long enough to get a pattern before collapsing? Or should I collapse the lifter completly before checking pattern and then add in the lifter piston travel. It seems that it might be hard to measure that accurately. I do have a checking push rod and a dial indicator.

Thanks
 

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On 2006-04-22 07:33, mntmotorrider wrote:
Hey guys, I'm about to go through this proccess also and I have one other question. I am using hydrolic lifters and I do not have a solid lifter to use during the checking proccess. How do you keep the lifter from compressing while you are turning the motor over? If you charge it with oil, will it hold its height long enough to get a pattern before collapsing? Or should I collapse the lifter completly before checking pattern and then add in the lifter piston travel. It seems that it might be hard to measure that accurately. I do have a checking push rod and a dial indicator.

Thanks
Do you have one of the old lifters?

It so you can disassemble it, flip the guts around, add shims, or fill it with JB weld if necessary to hold the disk in place so that it doesn't collapse.

You could even buy a single lifter just for checking--what would you spend, maybe $5?
 

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Discussion Starter · #16 ·
mntmotorrider

I did just that, took an old lifter, took it apart and cleaned it up. I then used washers to pack the plunger at its uppermost position then put the retainer back in. Now when checking it didnt compress. All Ive then done is add 0.030" to my measured rod length to allow fro the preload set with hydraulic lifters.

Hope that helps.
 

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I pumped oil into my lifters through the little hole in the side until it came out the top.It seemed to hold up fine although it was a fairly mild setup I was checking.If you have really stiff springs your probably better with the solid lifter.
 

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I threw the old lifters out long ago. I don't mind buying a checking lifter, but how do you know that it will be the same size with the same amount of travel in the plunger? I even asked my cam supplier, Cam Research, if they had a solid lifter comparable to the hydolics they sold me and they said they did not. The other problem I have is where I live, there's not much available over the counter, I have to mail/internet order everything. I can't be the first guy to install hydrolic lifters with roller rockers, there must be an easy approch to this.
 

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Thanks all, I think I'll try the method with the pumped up lifter first. My springs only have 100# seat pressure. If that dosen't work, I'll hunt up an old lifter somewhere. Do you set the rocker arm poly lock at zero lash or a half turn past zero lash like you do with stock hydraulic rockers?
 

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this is from Cranes sight about preloading lifters with oil.
Do Hydraulic Lifters Need to be Primed with Oil?

Many people mistakenly believe that hydraulic lifters must be soaked in oil overnight and be hand pumped up with a pushrod before installing into a new engine, however this is not necessary. In fact, this could cause the lifter to act as a "solid" and prevent obtaining proper preload. What is very necessary is the priming of the entire engine's oil system before starting up a new engine for the first time. This is done by turning the oil pump with a drill motor to force oil throughout the entire engine. Crane Cams offers oil pump primers for Chevrolet and Ford engines.

Here's the link to the tech page as well, this is how I did my valvetrain.
http://www.cranecams.com/?show=techarticle&id=2
 
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