Help camshaft trouble

[teddy839]

ok here is the situation i bought a camshaft to replace the stock one in my explorer it is comp cams part no.49-410-8. my machine shop guy (bare with me a second) told me to buy the stock lifters cause they are the same as the ones for this cam so here i sit after about 150-200 miles tapping away like they need replaced. so now that i have learned my lesson where can i get the lifters i need to fix this (for obvious reasons i don't trust the shop i got the motor done at) i tried vanir technologies but they never got back to me on what to do any help i can get would be appreciated.

 

[TDG]

I'm not aware that the lifters are any different from the stock ones, however due to the smaller back lobe on the cam the machine shop should have installed custom longer pushrods to make up for the difference.

 

[SteveVB]

stock lifters are the ones to use.

How do you know it is the lifters? The stock lifters are what you use for the cam, since its a roller cam you can reuse the lifters as long as they are in good shape. Did you check your oil pressure, and make sure oil is getting to the top of the engine?

When you rebuilt the engine did they mill the block and or heads? Did they replace the rocker arms? Did you reuse the stock push rods?

I would NOT reuse the rockers or push rods on any 4.0 rebuild. These parts wear and create decreased preload which leads to valve tap. Hardened replacements are the way to go. Smith Bros for the push rods, and someone makes a rocker that has a hardened cup for the pushrod - I can't remember the name now though. Do a search of the site.

I would check the preload on the lifters- 40-60 thou (.040 -.060- you guessed it .050 preferred), and look for any wear on the rocker arms.

I had to get new custom length push rods when I installed the 410-8 - chrome moly from Smith Bros - they were about $80 shipped I think.

Good Luck.

 

[teddy839]

whoops wrong wordage lol

sorry i meant push rods in stead of lifters i was thinking about how the shop told me the lifters would be able to make up the difference do u have a link for the site to get the pushrods
maybe they can help with the springs also i only have the stock ones from a stock rebuild

grrrr i hate gettting the shaft!!

thanks
teddy

 

[dzk007]

The shaft?

Heck, you didn't get the shaft - you got the ROD !!

Sorry about that, just couldn't resist. Ease up a little on the guy, he was just trying to save you a buck - I think. anyways, it's just a speed bump, drive over it and don't look back.
Also, I'd go back to the guy and let him know how things turned out. Or else he may give someone else the same bad advice.

 

[SteveVB]

www.pushrods.net

The shop was right about the lifters taking up some slack- they are designed to take care of some wear but the amount is limited, and when you use them to compensate for the cam any adjustment for wear is going to be limited. Always check length with cam installs.

You need to measure for new push rods with the lifters loaded .050 - or about the middle of the acceptable range. I used an adjustable pushrod to make my length measurements your shop should be able to figure it out, the procedure should be similar to any shaft mounted rocker arm set up. Smith Bros has a section on their site about measuring, plus a few other decent tech info.

I agree with the above- go back to the shop let them know what needs to be done, ask them if they checked it or not. They should be able to take the measurements so you can have the correct length made up. If they look at you cross-eyed when you mention preload and push rod length then it's time to say "GOOD BYE"


Link: www.pushrods.net