Thoughts on Crower Adj. Pushrods [Archive] - Classic Cougar Forums

: Thoughts on Crower Adj. Pushrods



twyluh
April 1st, 2008, 09:34 PM
So I measure my stock 390 pushrods; 5/16" shaft with 3/8" ball ends; and They are just a little bit long (9.62"). This I believe is contrbuting to my low vacuum and longer valve overlap.

So finding a 3/8 ball ball pushrod in the 9.4-9.5 inch range is difficult and it has come down to Crower Adj pushrods for hydraulic cam and non adjustable rockers.

I was kinda worried about using an adjustable pushrods in a motor but I bought one with a 3/8" shaft and 3/8" ball ends and it seems quite stout. (plus I'll only have about .100 inch of thread exposed)

I am thinking about going with a set of 16 (7000 series). These rods are made specifically for ford FE.

Anyone have any thoughts on this?
The plus is, if I go to roller rockers, I can just buy new cup tips for all the pushrods instead of having to get entirely new pushrods.
Also I can dial in the exact correct length and lifter preload for ever valve.
I am worried about spending alot of money on a custom set of pushrods, or just a nice set of non-adjustable and I get the measurement wrong...

Royce Peterson
April 2nd, 2008, 07:35 AM
The adjustable pushrods are heavy. They will cause you to have other problems, like valve float at a low RPM and broken pushrods.

You can get a set of pushrods made in any dimension or length you want here:
http://www.pushrods.net/

Smith Bros will ship the next day.

If you plan on roller rockers you should just wait until you have the money. You will need custom length pushrods for best results with the roller rockers too. Typically I end up getting pushrods that are .100" longer than stock when using Harland Sharp or Erson roller rockers in an FE.

twyluh
April 2nd, 2008, 09:40 AM
I've been reading about how heavier pushrods are not always bad even though lighter would seem better. (less weight in the valve train)
I've read some tech articles about how lighter pushrods can deflect and a 3/8" or larger pushrods can actually show a 15-20 hp gain over a thinner 5/16" (lighter) pushrod since there is less deflection.

Royce Peterson
April 2nd, 2008, 12:28 PM
Tyler,

Heavier does not mean stronger. The adjustable pushrods are weak even though they are very heavy. They are intended to be used either to determine proper length or as a problem solver for a car with a collapsed lifter or a worn out valve tip.

Dr.Art
April 2nd, 2008, 12:50 PM
listen to royce he is 100% correct

twyluh
April 2nd, 2008, 02:22 PM
Royce do you not reccomend the comp cams roller rockers?

Royce Peterson
April 2nd, 2008, 02:42 PM
I found them crudely made and difficult to set up. A friend bought a set and the holes for the rocker shaft had too much clearance which caused him to have to order oversize rocker shafts to make them work. Also the pushrod cups dig into the area next to the adjuster. You have to grind away the underside of the Comp rockers to give enough clearance without binding. Also some of the rockers did not have the oiling holes drilled that squirt oil into the pushrod cups.

The end support stands are really bulky and would not fit inside LeMans rocker covers. We had to grind away on both of the end supports and also the inside of the valve covers to achieve enough clearance. Just too much trouble.

When you are paying several hundred bucks for a set of rockers it should be reasonable to expect them to work with a minimum of screwing around.



Royce do you not reccomend the comp cams roller rockers?

428cougarguy
April 2nd, 2008, 02:56 PM
Royce, I'm thinking of purchasing a set of FE roller rockers within the next few months...The application would be a 1969 Cougar Eliminator, C6 auto, 3.50 posi, 428 CID engine, 30 over, with reworked 390 heads with larger valves, dual plane intake, and hooker super comp headers. Hoping to get around 450 HP out of it. What valve train components would you recommend? Thanks!

69LMN8R
April 2nd, 2008, 03:05 PM
I also highly recommend Smith Bros. pushrods. Had a 6500 rpm (in the lights) 429 in a '80 Capri and broke a pushrod about once a month (Ford Motorsport Hardened for guide plates for Lunati solid lift cam). Tried a couple of others with basically the same results. Switched to Smith Bros. and went two years without another problem. Also used Harland Sharp Roller Rockers during the same time period without a failure. Changed valve springs once a year (100+ passes) checked valve lash once a month or so and had a trouble free valve train.

Art
April 2nd, 2008, 03:35 PM
They are just a little bit long (9.62"). This I believe is contrbuting to my low vacuum and longer valve overlap.


I believe you're barkin' up the wrong tree....

twyluh
April 2nd, 2008, 04:30 PM
I believe you're barkin' up the wrong tree....

Well then what would the longer pushrods be doing? excessive lifter preload if they are just a shy to long?
according to comp cams..

"
Q. How do I adjust my hydraulic lifters (non-adjustable valvetrain)?
A. When installing a hydraulic camshaft or lifters, or new rocker arms, it is necessary to establish the correct lifter preload in order to ensure great performance and long engine life. Insufficient preload will cause excessive valve train noise and wear. Excessive preload will cause rough idling and low manifold vacuum, and can even lead to severe engine damage. With a non-adjustable valvetrain, proceed as follows:"

I have had those syptoms and have no vacuum leaks and mesaured the pushrods to be a shy too long. What else would contribute the low vacuum? I switched camshafts to a magnum 270H and I have no vacuum leaks.

Royce Peterson
April 2nd, 2008, 09:25 PM
Have you measured how far the plungers are being depressed (aka "lifter preload")?

Something like .050" - .100" is appropriate for Comp Cams standard hydraulic lifters. The Magnum Series lifters are only supposed to be depressed .010" - .020".

Royce Peterson
April 2nd, 2008, 09:28 PM
I am a big fan of Harland Sharp roller rockers and hardened rocker shafts for FE. I also use Precision Oil Pumps end rocker supports and rocker spacer kits.

http://www.supermotors.net/getfile/582271/original/mvc-081f.jpg


Royce, I'm thinking of purchasing a set of FE roller rockers within the next few months...The application would be a 1969 Cougar Eliminator, C6 auto, 3.50 posi, 428 CID engine, 30 over, with reworked 390 heads with larger valves, dual plane intake, and hooker super comp headers. Hoping to get around 450 HP out of it. What valve train components would you recommend? Thanks!

twyluh
April 2nd, 2008, 09:49 PM
Have you measured how far the plungers are being depressed (aka "lifter preload")?

Something like .050" - .100" is appropriate for Comp Cams standard hydraulic lifters. The Magnum Series lifters are only supposed to be depressed .010" - .020".

Royce from the Comp cams site:
"
COMP Cams® High-Energy™ lifters will require .030” to .050” preload. The more competition-oriented hydraulics lifters, such as the Pro Magnum™ series will require only .002-.004” preload, which will typically require a dial indicator to set correctly.
"
And then I called Comp Cams cam help line and they suggested .020"
to .040" of preload, emphasizing that .030 was ideal.
When I measured the depressed length of the rods on the base of the cam, it was a little more than .100". I used a flat and sharp razor blade to score marks in the pushrods, from the measuring instructions in the Comp Cams installation guide.

Art
April 2nd, 2008, 11:47 PM
Royce from the Comp cams site:
"
COMP Cams® High-Energy™ lifters will require .030” to .050” preload. The more competition-oriented hydraulics lifters, such as the Pro Magnum™ series will require only .002-.004” preload, which will typically require a dial indicator to set correctly.
"
And then I called Comp Cams cam help line and they suggested .020"
to .040" of preload, emphasizing that .030 was ideal.
When I measured the depressed length of the rods on the base of the cam, it was a little more than .100". I used a flat and sharp razor blade to score marks in the pushrods, from the measuring instructions in the Comp Cams installation guide.
Another way to kill some of the preload is to shim underneath the rocker stands even though using a shorter pushrod is preferred.

Stay away from the adjustable pushrods, way more trouble than they're worth.

Too much preload will prevent the valves from closing, too long a pushrod won't have any effect on valve timing.

I always use a dial indicator to set lifter preload. Set it and forget it.

dfwcatsclub
April 3rd, 2008, 12:45 AM
So I measure my stock 390 pushrods; 5/16" shaft with 3/8" ball ends; and They are just a little bit long (9.62"). This I believe is contrbuting to my low vacuum and longer valve overlap.

So finding a 3/8 ball ball pushrod in the 9.4-9.5 inch range is difficult and it has come down to Crower Adj pushrods for hydraulic cam and non adjustable rockers.

I was kinda worried about using an adjustable pushrods in a motor but I bought one with a 3/8" shaft and 3/8" ball ends and it seems quite stout. (plus I'll only have about .100 inch of thread exposed)

I am thinking about going with a set of 16 (7000 series). These rods are made specifically for ford FE.
These are in stock http://store.summitracing.com/partdetail.asp?part=TFS%2D21419500%2D8&autoview=sku

twyluh
April 3rd, 2008, 10:53 AM
These are in stock http://store.summitracing.com/partdetail.asp?part=TFS%2D21419500%2D8&autoview=sku


Yea but those have 5/16" tapered ball ends, not 3/8" ends.

I think I will use that one Crower adjustable pushrods to dial in exactly how much shorter the pushrods need to be and I'll try a shim pack to see if that helps my vacuum until I get some roller rockers.

Royce Peterson
April 3rd, 2008, 11:30 AM
That sounds like a good plan.

Honestly though if all the lifters are depressed the same amount and it is less than .100 it should not have any effect on your vacuum.


Yea but those have 5/16" tapered ball ends, not 3/8" ends.

I think I will use that one Crower adjustable pushrods to dial in exactly how much shorter the pushrods need to be and I'll try a shim pack to see if that helps my vacuum until I get some roller rockers.