Push Rods

[orgnl70]

I am building a 390 Fe motor with Edelbrock cam and lifters. Using stock rocker arms. My problem is the lifters use a 5/16" ball and the rockers use a 3/8" ball.
No one seems to have one listed. Any suggestions?

[blykins]

Easy-peasy.  Call trend or smith brothers, depending on which side of the country you are.

I do that combo all the time.

[My427stang]

I haven't seen a mismatch on the Performer cams and lifters, are you sure there is an issue, or are you using an odd combo of lifters?

FYI - totally agree with Brent, easy to buy custom pushrods, but might be as cheap or cheaper to run a stock style pushrod with a matching lifter, especially if it's a mild one

[Falcon67]

X2, get with Brent on the length and configuration you need and he can get you parts with very decent pricing.

[scott foxwell]

Unless it's an OEM replacement lifter it's most likely going to have a 5/16 cup. Most people don't even realize this and run 3/8 ball pushrods or if buying aftermarket like Comp, run 5/16 ball in both ends. ONe way or another it's going to be wrong. We use Smith Brothers and can order pushrods any way you like.

[My427stang]

So I just went outside and measured a set of Comp 834s and a set of old stockers out of a 71 360.

Both had a pushrod seat diameter of .340.  5/16 is .3125, so it seems like these anyway are made for 3/8 as if you sunk a 5/16 ball it'd be sitting on the bottom and likely wear both the lifter at the hole and sharpen the pushrod over time.

I do not have any Comp 832s to see how they are made differently, but I suspect the small block and 385 series maybe a bit different and some companies try to cheap out without using the correct lifters.

We just ran into something similar on a 67 GTO 400 HO, stock rebuild done by previous owner, but noisy lifters and when we went in it had poly locks.  As far as we can figure out, the previous owner used Chevy lifters, which have both a lower cup height and a lower oil band height.  He tried to make up the cup height with adjustable valve train, but the oil band was actually coming slightly out of the bottom of the llifter bore on the base circle.  No adjustment will let that hold oil LOL 

[scott foxwell]

So I just went outside and measured a set of Comp 834s and a set of old stockers out of a 71 360.

Both had a pushrod seat diameter of .340.  5/16 is .3125, so it seems like these anyway are made for 3/8 as if you sunk a 5/16 ball it'd be sitting on the bottom and likely wear both the lifter at the hole and sharpen the pushrod over time.

I do not have any Comp 832s to see how they are made differently, but I suspect the small block and 385 series maybe a bit different and some companies try to cheap out without using the correct lifters.

We just ran into something similar on a 67 GTO 400 HO, stock rebuild done by previous owner, but noisy lifters and when we went in it had poly locks.  As far as we can figure out, the previous owner used Chevy lifters, which have both a lower cup height and a lower oil band height.  He tried to make up the cup height with adjustable valve train, but the oil band was actually coming slightly out of the bottom of the llifter bore on the base circle.  No adjustment will let that hold oil LOL

Comp's FE pushrods are 5/16. I guarantee you their Ford lifters are all the same parts. The 832 and 834 have a different seat height but other than that I bet they are the same lifter.

[scott foxwell]

Comp 834 lifter. Top of the radius measures just under 5/16.



Notice the wear pattern around the top of the radius. This lifter had a factory 3/8 ball riding in (on) it. This is out of my 390.

[Barry_R]

Some lifters have a "chalise" profile on the inner cup with a variable radius profile which can accept a 3/8 or a 5/16 ball.

I have Trend make my custom stuff and they do a 5/16 one end and 3/8 on the other to any length you desire.

[My427stang]

Here is a pic of a Comp 834 with a slightly different wear pattern, I think the cup looks slightly different but hard to tell exactly.  I wonder if Comp changed them at some break point to reduce cost?

I don't have a way to measure radius, but the top of the cup is larger than 5/16 and the 3/8 pushrod sits a little deeper, so I'd have to assume it's a different seat

[scott foxwell]

I'm going to look at all 16 lifters when I get home. I'd bet a dollar to a donut that I'll find a few like yours. You can see the 3/8 ball still isn't sitting "full radius like a Ford factory lifter.
In the end I'm not sure how much difference ot makes with most of this stuff. Not really enough spring pressure and load to cause any excessive wear and the pushrod isn't going anywhere. Solid lifter or roller with some spring pressure and I wouldn't want to point-load the pushrod ball like that.

Ford lifter;

[My427stang]

I'm going to look at all 16 lifters when I get home. I'd bet a dollar to a donut that I'll find a few like yours. You can see the 3/8 ball still isn't sitting "full radius like a Ford factory lifter.
In the end I'm not sure how much difference ot makes with most of this stuff. Not really enough spring pressure and load to cause any excessive wear and the pushrod isn't going anywhere. Solid lifter or roller with some spring pressure and I wouldn't want to point-load the pushrod ball like that.

Ford lifter;

Pretty wild that the range of "good enough" is so wide with the aftermarket manufacturers.   

[scott foxwell]

I'm going to look at all 16 lifters when I get home. I'd bet a dollar to a donut that I'll find a few like yours. You can see the 3/8 ball still isn't sitting "full radius like a Ford factory lifter.
In the end I'm not sure how much difference ot makes with most of this stuff. Not really enough spring pressure and load to cause any excessive wear and the pushrod isn't going anywhere. Solid lifter or roller with some spring pressure and I wouldn't want to point-load the pushrod ball like that.

Ford lifter;

Pretty wild that the range of "good enough" is so wide with the aftermarket manufacturers.

It's unfortunate, that's for sure.

[gdaddy01]

oh no , something else for me to check . I put comp 270s kit in my 1961 hp and used the stock push rods , did not even think to check this . ass u me nothing . been running about 12,000 miles , I should have a wear pattern by now , lol

[scott foxwell]

oh no , something else for me to check . I put comp 270s kit in my 1961 hp and used the stock push rods , did not even think to check this . ass u me nothing . been running about 12,000 miles , I should have a wear pattern by now , lol

If it ain't broke...