I just got back from vacation and have not brought myself to sitting in the garage in the heatwave going on in the midwest. I still need to purchase the pushrods for the engine.

I do not have a pushrod checker, but I still have the pushrods from the original L48. Can I install one of those pushrods and turn the engines a few revolutions to make sure the rocker is situated correctly on the valve? My thought was that if I could do this and it matched up, then I know I need the standard length pushrods.

 

I don't want to sound like a grump but i have posted this too many times. Try a archive search but a checking tool is very cheap ($10) and the comes with instructions. Easy job using the checker tool but very difficult using the adjustable p-rod method. Believe me use the checker and in 5 min your done, then order the correct p-rods. BTW yes, u will need 1 of those stock p-rods to measure with. But go ahead try the adj p-rod and you'll need a solid lifter (the exact length of the hyd lifter) also, then pack a lunch because you'll be rotating the eng all day.

Good luck,
cardo0

 

Where can I get a pushrod checker? None of the regular chain auto parts stores seem to have them.

 

http://store.summitracing.com/egnsea...40&D=%2D108240

Here's the one that I used when building the 406..

http://store.summitracing.com/partde...1&autoview=sku

 

So is that one different that the adjustable pushrod method that cardo0 was referring to?

If I use one of those, does it come with measurements on it? I don't have anything that will measure the length. My micrometer only goes up to 6".

 

IMHO there's no harm in doing the mock-up with the stock pushrod to see where you're at. You need to ensure that the rod is straight, either by rolling it on a surface plate (a 1" thick piece of glass works) or chucking it up in a drill press to see that it spins true.

This is ultimately not a precision measurement - you're looking to see that the rocker tip gets no closer than 1/3 valve tip diameter to the edge, and is about in the middle at 1/2 lift. "1/2" and "1/3" is not .0001.

During mock-up, we're not just checking pushrod length, but also coil bind, rocker clearance, etc.

The checker that Cardo0 is referring to is something like this:

http://store.summitracing.com/partde...9&autoview=sku

I agree it's a quick check on pushrod length (really quick ) but the rest of the mock-up checks are still required. That's why I generally choose to install light springs on #1 and do all the checks with an adjustable pushrod. It's more work...but you're checking everything you need to and can quickly make changes to get it right. As noted, you do need a pair of mechanical lifters that have the same installed height as your hydraulics.

Overall, it's a critical check that you must do...but unless there was significant cuts made on the block and head (more than a .003 - .005 cleanup cut) then you're not likely to have a problem.

 

I don't know what cardo0 is refering too.. I just know that I used the adjustable pushrod and it worked great for me.. I used a regular tape measure to measure the length of the adjustable pushrod (after figuring out of what adjustment would work best). Turned out that the ideal was between 7.70 and 7.80 pushrod length. Ended up buying the 7.80 inch pushrods as they were in stock.. 7.70 and 7.75 would also have worked..

 

the adjustable pushrods that comp sells have graduations so that you don't need to measure them; can't anyway due to different end types. would imagine that all brands are graduated . . .

 

Sorry for the late reply DG. Like Mr. billa has said its not an exact science and the objective is to keep the rocker tip off the edge of the vlv tip - that would cause side loading on the vlv stem and premature wear.
All u use to measure with is a feeler gauge - well when using the checker tool that is. Consider the hyd lifter pre-loand and then u can imagine how your going to measure this with an adjustable p-rod. But if u try it please share your experience here.

Another item is once u receive your new p-rods don't be surprized if they are little long or short. My Trick Flow rods measured a few thou " longer than the size that was even lazer echted on the new p-rods. But since using them i looked at the wear pattern on the vlv tip and its right where its suppose to be. So don't over scerutinize here (a rare exception).

BTW i saw in your previous pix u are running Sportsman II heads. I like the World Products heads too but am using the smaller Torquers. I had mine pocket ported and the shop unshrouded the vlvs also.: : This is a major improvement on these heads for not much money and I wanted to recommend it to u before the engine goes in the car. The port porting wakes up an already good head (30hp maybe/possibly).

Well hope this helps ya',
cardo0

 

I measured the stock pushrod from the L48 and it was right at about 7.78. I then put a new lifter, the stock pushrod and the rocker arm on the engine. I tightened it to zero lash, then 1/4 turn. I looked at the position of the rocker tip on the valve. It was slightly on the off center. I rotated the engine until that valve opened and watched how far the tip went across the valve. It travelled across to the valve to virtually the exact opposite position on the other side of the valve. I did this a few times just to confirm.

As far as the heads go, these heads look to have some minor porting and polishing on them. They were cleaned up pretty well by the machine shop.

 

One tip I have seen is to use a sharpie and color the tip of the valve black. Then set the rest of the valve train up for that cylinder. Rotate the engine through for a couple of rotations and check the valve tip. It should have rubbed the black off where the rocker will ride the valve. You can then judge whether or not the rocker is riding the valve in the correct position.

 

Yep, I do the same thing but with Prussian Blue.