Hey all, I was planning to put a set AFR heads on, and was pretty confident that I'd be able to do it myself until I read about having to measure for new pushrods in order to assure they are the correct length. I contacted AFR and asked if they could recommend a pushrod length based on using the stock cam, and 165 heads. They told me that the measurements had to be taken at the time of installation. Has anybody done a headswap on their 94 GT, and measured for new pushrods, or done the swap with measuring? Thanks for your help, Rob
Never had to measure for custom push rods but they make adjustable length rods you can purchase to find your desired length. Plus there is various how-to videos on Youtube. Good Luck.
AS Doc already stated you can get an adj pushrod. Install rockers and tighten to spec, make sure rocker is centered on vlv, adj pushrod as necessary. Remember to rotate the engine through a couple revolutions to ck for minimal movement on the vlv.. You could install the origional pushrod to ck for location. but do you really want to put old used pushrods in a new build?
Why are you swapping AFR heads and not upgrading your camshaft? Also measuring pushrods is easy get the trick flow measuring tool and read read read and watch videos and you'll find its sounds scarier than it is
Thanks for the responses guys. I'd like to stick with the stock cam for various reasons. AFR showed good results with the stock cam. I'm also concerned about driveability issues, and dyno tuning requirements. I also like the idea of keeping the power in the lower end, as it's just a weekend cruiser and occasional road trip car. So in most cases when performing a head swap, you guys have measured pushrod length? Cheers, Rob
I used stock length with my AFR heads but it is good to check. I used one of my stock pushrods to check and was happy with the mark it made so I bought hardened pushrods the same length.
Thanks again guys. I guess I'll read up as much as I can on the subject. Hopefully I'll be able to pull it off. Cheers, Rob
Yeah.... Unless he has some lightweight checker springs, which are hard to get a good read on the valvetip, he needs to disassemble a few hydraulic lifters, remove the plunger and spring, install a stack of washers, put the clips back in and reinstall the lifers, using them with the adjustable length pushrod to dial in pushrod length...
i made a solid lifter out of a stock one just by flipping the plunger, seemed to work okay but it's been a while now since I did it.
You can do it by flipping the plunger. You also only need to make one, you can just do the intake valve, then exhaust valve. Use your old compressed headgasket to get an accurate reading. If you don't use a solid checking lifter, the valvespring will compress the hydraulic lifter because you'll have no oil pressure to keep them pumped up. You can use the checking springs... but its hard to get a good witness mark with those. You'll also want a set of digital calipers to measure whatever length you are happy with on the adj. pushrod and order that length. It really isn't hard to do this, just a little bit of a PITA. If you have an old lifter, a checking pushrod and a sharpie you can do it pretty quick.
The pushrod length checked that doesn't have the length listed on the side. Depending on your engine when you order your checker ( it's minimum and maximum length) the instructions with it tells you how much length each turn is and you just count how many turns you made and add that to the minimum length and well ah! Checking pushrod length isn't hard. You can buy a lunati solid lifter for like 3-5 bucks saves time but you can make a solid out of a Hydraluic using the methods listed above. Here's a link http://www.carcraft.com/techarticles/116_0401_setting_pushrod_length/?__federated=1 showing how to check your pushrod length and it explains it very well! Let me know if you have any other questions I'm more than glad to help you figure it out!
