Just to jump on the bandwagon: check and recheck everything when installing high performance parts and then have someone else check it!

Rich - who has also graduated the "School of Hard Knocks"

 

It would be interesting to know what springs those are. When I ordered my 306 cam I was told it was either dual springs which need the spring seats on the heads machined or beehives. There was no single spring option other than the beehives. I also get the impression that you didn't buy these parts new so how many miles are really on them?

 

Does all this geometry and measure apply when you are just installing 1.6rr's GMPP rr's w/ LT4 springs/Locks/Retainers and a set of new hardened stock size pushrods from comp cams? on a stock cam/bolt on car.

I thought setups like this required no measuring etc...?

 

Yes. Any time you change---you check. We're not talking a major undertaking here. As long as the springs will accommodate the lift of the RRs with the required amount of margin, as long as you get the proper quides for your Non-SA RRs along with the hardened PRs, and as long as the length of the rods are correct for the best geometry---you are good to go.

But....you still need to check the geometry even though it may seem that nothing needs changing. So since you already have the stock PRs---even though they are not hardened. You can check to see whether your RRs on that pot are hitting the valve stems correctly, i.e, from the first 1/3 of the valve stem to the 3rd 1/3 of the valve stem and back and in the middle of the valve stem and not off to the side. You also check to see that the PRs are not rubbing on anything. I.e. this preliminary check will tell you if you need to take the next step which would be to get an adjustable PR to see the exact length needed for the best geometry.

My initial guess would be that getting the stock length hardend rods will do the trick, but don't assume anything when it comes to geometry. If you order the wrong sized rods, you might have trouble returning them or at least bear the cost of shipping, handling, etc. and have to wait for all this. So by doing the initial checking you save time and money. By not checking you risk the integrity of the valve train and perhaps the possiblilty of losing an engine.

Even if you go ahead and order the stock length PR, you still need to do the checking---so why not do it before you order them.JMHO

 

I just don't understand the point of checking the stock pushrod length when you are ordering the stock length again? I could see if you were going NON SA and new lifters/cam but w/ stock everything else?

 

My bad: I assumed----something you shouldn't do. I.e, when you say you are getting "hardened" push rods, I "assumed" that you are going with Non-SA RRs, since you don't really need the harded rods if you are not going to have guide plates, since the purpose of the hardend rods is so the quide plates don't erode the surface of the non-hardened rods.

But...again, since you are switching to RRs, you really should, for piece of mind, if nothing else, slap one of the RRs on and using the stock rods that you already have and check how the rollers contact the valve stem. Which usually requires nothing more than a marking pen to mark the valve stem and see where the roller contacts the valve stem. Voila!

Should'nt take but a few minutes. BTW, if you're concerned about the extra couple of minutes to check it out, I would think that it would be somewhat inconsistant with your willingness to pay extra money for hardend rods when your current rods would work just fine with your SA PRS.JMHO

And, don't "assume" that eveyone who offers advice here follows their own advice. It's kinda like " this is technically and reasonably how things should be done" even though I didn't or probably wouldn't bother doing it.

But wouldn't you rather have someone offer good advice rather than tell you not to worry about it because it's "probably" alright.

Finally: putting higher ratio RRs in to increase the lift is kinda like putting a cam in with a higher lift. I.e. you can very easily keep the stock rockers and just go with a cam. Bottom line---either or both change the lift. So why not make sure the change in the lift---a little or a lot---doesn't screw up your geometry.

Ur car, sup 2 u.

 

Oh...and wherefrom I speaketh: When I first bought my new 97SS, the first thing I did was get 1.6RRs. As a Newbie, and without the benefit of this site, I bught some hardened stock plus .050 prs, cause they went with the RRs in the AD. I. e., I "assumed" that the RRs needed the longer PRs. Well the next thing I did was have a cam installed and the heads ported. The next thing that happened was I spun a bearing probably because a bad install and the next thing that happened after installing a new short block was to drop a valve when my RR beat the hell out of my keepers, ruining the SA RR and dropping valve and kissing the piston. Was really lucky that no damage occured since I shut it down at once.

But after looking over the situation, my NEW mechanic determined, among other things, that my PRs were too long and the geometry was off. So I ordered new stock length PRs (I did, however get the hardened ones,even though I didn't need them with the SA RRs----just felt like it.

Bottom line, I apparently did not need longer PRs and I would have known that if I knew enough to check the geometry when the 1.6s, cam and head were installed. And since my first mechanic didn't bother checking the geometry, I damn near had to buy another short block---that would have made 2 new short blocks with only 7500 miles on the car.

So in my case even with the RRs, cam and heads, my stock length was the correct length. But to assume w/o checking can be a costly adventure.JMHO

 

Thats where it gets messey. I have a 96 so apparantly they are not hardened from the factory so people say to go out and get hardened ones even when upgrading to just SA. If there isnt a problem w/ re-using the stock ones I will do it...

 

If you are mot using guide plates, do not get hardened PR's. They are more brittle than non-hardened. They are NOT an upgrade if they are not needed for use with guideplates.

Rich

 

See: Krause just saved you some $. Now you can get some of those Patriot springs with the titanium retainers--good to 600 lift (for your future cam) or use the saving to buy some more goodies.

 

I had the "hardened" factory pushrods as well. They went about 4000 miles before they we junk.

Pushrods are cheap.

 

If you are running a mild cam, most any PR will do. If you are running a lot of cam (with the requisiite spring) something more than stock replacement quality is needed. Manton is a great source for PR's. They have a whole range (from ~7 all to way to $30+ per) and can tell you which you need and supply them in any length in a day or two.

Good people to deal with.

Rich

 

When I installed LT4 springs and CC 1.6 Promags I had to change from the stock 7.200" rods to to 7.050" rods to maintain correct geometry. Before I did this I lost a valve because I was stupid.

 

That couldn't be farther from the truth. The last thing you want a pushrod to do is flex, and thats what stock ones will do, or the cheap hardened ones. The chromoly pushrods are the only ones that belong on a car with aftermarket springs.

 

I don't think you have the slightest idea of what you are talking about. Of course, you don't want PR's to flex. But hardening has nothing to do with whether they will flex or not. The reality is, all PR's DO flex. Stiffer, is better. But stiffness and brittleness are not the same thing.

Rich