DO I need shorter pushrods? May 08, 2005, 11:04:19 PM I got the heads on and I'm doing the rocker arms... I had to use .0950 of shims on the 4 rockers that I put on so far. I got them torqued down right and I'm still able to spin the pushrod and have no up and down movement, they feel good but the shims look rediculis... Is this too much? Should I look into pushrods that are 0.050 smaller than stock and shim from there.. I guess these heads are milled more the 0.005 like the seller said...Maybe he thinks 5 thousands is 0.050 seems right since I need a pushrod 0.050 smaller..I'm using the 1.6 svo blue rockers (ped mount) stock length harded pushrods, and the 6037's I bought used.. Quote Selected
Re: DO I need shorter pushrods? Reply #1 – May 09, 2005, 12:12:57 AM might just want to get new pushrods anyway. my buddy put a cam in his motor and just replaced em sence they were the origionals with over 100k on em. and i rember him telling me their cheap. then again, i'v only helped with engine builds, never did a whole one yet. Quote Selected
Re: DO I need shorter pushrods? Reply #2 – May 09, 2005, 01:09:16 AM Properly set-up pushrods will spin but not have end-play. Many a Chevy owner has adjusted the valves until the pushrods were tight, & ruined the engine upon startup because the lifter plungers were bottomed out. Quote Selected
Re: DO I need shorter pushrods? Reply #3 – May 09, 2005, 01:13:23 AM i dont think so,,, wait til you get er started up and let the oil pump and prime the lifters for you. the lifters should eat up that little bit of slack anyway. besides, you should be going back in to recheck the torque after a quick start anyways plus to tweek in any noise on individual rockers while running.it happens all the time,,,, both valves closed and rockers torqued. ,, but,,, the pushrod feels loose as hell. you probably dont need any shims,, the lifters will take up that slack.your only other option is to think for a moment that he did infact only take of .005 instead of .050. If he did take off only five thousandths, then you found your problem.,,no shims needed.mic out the height of your head and maybe compare it to a stock head height.,, subtact the difference and see what you come up with.i know one thing is for darn sure,, if he took off .050 ,, you would have noticed a rather obvious miss alignment when you started to land your intake bolts.,,,(head is shorter on both sides so sometimes the intake needs milled as well to match up)so u got two choices,, find out how much was taken and act from there.either way, id try no shims in either case and they will be tight. If your compression is low all around and lower than you expect plus some backfire,, then shim low to give the pushrod some elbow room. im pretty sure that not shimming will be the case here for you.in installed 289 heads on a 302 shaved down .060 and still got away with factory pushrods even with aftermarket 1.6 steel roller rockers.289heads are a wee bit shorter than the the heads we deal with today on these cars. Quote Selected
Re: DO I need shorter pushrods? Reply #4 – May 09, 2005, 06:43:10 AM Quoteit happens all the time,,,, both valves closed and rockers torqued. ,, but,,, the pushrod feels loose as hell. you probably dont need any shims,, the lifters will take up that slack. You guys are miss reading what I'm saying.. My problem is opposite to this, when the lifters pump up fully It will be worse I would think..When I set the rocker up on the head and tighten by hand. I turn it till the pushrod has no up and down movement and can still spin nicely. Now When I go to torque it down I can see that the rocker is NOT seated on the head. So as your starting to torque it down you can see the valve opening up..If I bolted them down with no shims every valve I did would be open slightly I can see the valve spring compress as I tighten. Yes both lifters are at there correct hieght and I'm setting them up on the correct time in the cam like the directions say.I know I need shims I'm just concerned that I have TOO much shim (0.0700-0.0950 so far on the couple I did) and should be looking into a shorter pushrod Thats why I was thinking of getting a pushrod that is 0.050 smaller than I would only need 0.020-0.045 in shims... (from what I know so far cause I only did a couple valve) I would need to check them all than order pushrods Quote Selected
Re: DO I need shorter pushrods? Reply #5 – May 09, 2005, 08:46:17 AM Okay Nick solved it... I forgot to take the spacer/Ushaped looking thing off my old heads..Now all I need to do is Find Nate today and get the pieces off my old heads Quote Selected
Re: DO I need shorter pushrods? Reply #6 – May 09, 2005, 09:01:44 AM oh,, i did not know your valves were opening. did you forget the rocker guide plates? do you still need shims? Quote Selected
Re: DO I need shorter pushrods? Reply #7 – May 09, 2005, 09:24:23 AM Yeah I'll still need 1 shim Nickyboy says that the guide plate is about 0.060" so it all adds up now.. Plus I was wondering why them shims were so hard to keep straight :) Quote Selected
Re: DO I need shorter pushrods? Reply #8 – May 09, 2005, 05:59:56 PM .Sorry man but it is kinda funny,now that you've solved the problem.It's amazing what we forget when we take apart :D .Hopefully when i do mine i won't forget anything,thankfully i know my heads have not been milled and have been ok'd by the machine shop therefore my bag of shims should not be needed but we'll see.Let us know what she goes like when you GET ER DOOOOOOOOONE! Quote Selected
Re: DO I need shorter pushrods? Reply #9 – May 09, 2005, 11:04:58 PM Hey its been like 8 year since I messed with a valvetrain :lol I was wondering why the freaking shims were so hard to keep straight... lol...when I get her running I'll take some video shots Quote Selected
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