Rocker install
Printed From: CorrectCraftFan.com
Category: Repairs and Maintenance
Forum Name: Engine Repair
Forum Discription: Engine problems and solutions
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=24797
Printed Date: October-07-2024 at 10:59pm
Topic: Rocker install
Posted By: Jllogan
Subject: Rocker install
Date Posted: February-05-2012 at 10:10pm
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I just bolted on my new gt40p heads and am reusing my old rockers, lifters and rods. Do I need to check the rocker to valve clearance? Is it possible I may need different length pushrods? Do I need a lifter compressor tool to check the clearance between the rockers and valves? ------------- http://correctcraftfan.com/diaries/details.asp?ID=5792&sort=&pagenum=1" rel="nofollow - 1986 Ski Nautique 2001 |
Replies:
Posted By: Gary S
Date Posted: February-05-2012 at 10:25pm
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Justin you need to check your http://www.cranecams.com/pdf-tech-tips/hydro-lift.pdf - lifter preload ,this is just one way to do it. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1711&sort=&pagenum=1&yrstart=1966&yrend=1970" rel="nofollow - 69 Mustang HM SS 95 Nautique Super Sport |
Posted By: Jllogan
Date Posted: February-06-2012 at 11:59am
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ok, the ford power manual described a technique using a lifter compressor tool. In that crane desription they just torqued them waited, made a mark and took the torque off and measured the change. Correct, seems much simpler. ------------- http://correctcraftfan.com/diaries/details.asp?ID=5792&sort=&pagenum=1" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: TRBenj
Date Posted: February-06-2012 at 12:29pm
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So long as youre not shimming out the wazoo, you should be fine with your rocker to valvestem geometry. Thats one of the advantages of a non-adjustable valvetrain. If you want to check it, then color the top of the valvestem with a sharpie (prior to installing rockers) and roll the motor over a few times- the rocker tip should wear the marker off roughly in the center of the valve stem. Too far off to the top or bottom would indicate less than optimal geometry.
I didnt read Gary's link to the Crane instructions, but here is the http://www.compcams.com/Technical/Instructions/Files/COMP4-116.pdf - Comp version on how to adjust lifter preload. Make sure you read the non-adjustable valvetrain section. Get some rocker shims- a kit is about $10. Measure each lifter individually- I had variations of up to .060" between rockers. If you have to shim any more than .090" to reuse the original pushrods, then you may want to consider new (shorter) ones. ------------- |
Posted By: Jllogan
Date Posted: February-06-2012 at 12:35pm
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yes, I was wondering about the shims. I have no shims now, I just took the stock rockers, rods and lifters off the old heads and put in the new. In the same order and piston position of course.
I am also correct in thinking that the only way to reduce the preload if it is too high is to get shorter rods. Right? Those comp directions are the same seems to be the way to do it. ------------- http://correctcraftfan.com/diaries/details.asp?ID=5792&sort=&pagenum=1" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: TRBenj
Date Posted: February-06-2012 at 12:42pm
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To reduce preload, you either need to shim the rocker or get shorter pushrods.
If everything is installed now, then go around and mark your pushrods (make sure the cam is on the base circle when you do this) and then pull everything off and remark and measure the difference. ------------- |
Posted By: Jllogan
Date Posted: February-06-2012 at 1:16pm
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ok I will go mark everything, by base circle you mean on top of compression stroker? Valves closed?
To increase preload I will need to get longer rods, right? just ordered a shim kit. ------------- http://correctcraftfan.com/diaries/details.asp?ID=5792&sort=&pagenum=1" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: TRBenj
Date Posted: February-06-2012 at 1:24pm
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Yes, cam on base circle = valve closed.
Yes, to increase preload you would need longer pushrods... but this scenario is unlikely unless youre installing a new factory head, and even then, the stock pushrods *should* be ok. When you install used or remanufactured heads, theyve usually been resurfaced- so all else being equal (reusing all the same parts), lifter preload would increase by roughly the same amount as the material removed (~.020-.030"). ------------- |
Posted By: Jllogan
Date Posted: February-06-2012 at 1:44pm
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gotcha, thanks tim! ------------- http://correctcraftfan.com/diaries/details.asp?ID=5792&sort=&pagenum=1" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: lakedog55
Date Posted: February-08-2012 at 10:55pm
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Justin,
If you do not mind let us know how the install went, Hopefully how much better it runs, I am getting ready to bolt on a pair myself soon as I can hide 350 from the wife for a freshen up on the pair I have. I was wanting to know if you can feel the difference. Mike ------------- Lakedog55 |
Posted By: Jllogan
Date Posted: February-15-2012 at 11:17am
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ok so I need some more advice here. I followed the instructions and giving and I noticed that according to the scribe marks they were pretty consitently measuring around .090. So too much preload so I was put .060 shims in and started noticing after the shims were in when the valves were closed the rockers were real loose.
I can spin the pushrod and actually then I noticed I could rock the rocker back and the pushrod back down by hand. Is this normal? am I doing something wrong. When I took them off the old heads they were not this loose. Thoughts? advice? ------------- http://correctcraftfan.com/diaries/details.asp?ID=5792&sort=&pagenum=1" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: TRBenj
Date Posted: February-15-2012 at 11:42am
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Sounds like you did something wrong. 0.090 - 0.060 should have left you with a preload of 0.030 (just about perfect). If you could spin the pushrods and the rockers were loose, then you had none at all.
Im also surprised that you had consistent preload across all the valves. Like I said before, mine varied up to 0.060 between valves. (I shimmed from 0.030 to 0.090.) Sounds like you need to start from scratch and re-measure the preload on each lifter without any shims. ------------- |
Posted By: 81nautique
Date Posted: February-15-2012 at 11:51am
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are these new lifters? They may need to be pumped up and try again. tightening the rocker down with out oil pressure can force the oil out of the lifter. Do you still have the intake off, if so pull lifters out one at a time, submerge in a can of oil and pump them up using a pushrod. Reinstall and see what happens.
There's a point where you have to trust your measurements, if you have confidence in them then button it up and fire it. You'll know right away if they're loose but my guess is they will pump up and be fine. Easy enough to check again after you get some oil pressure in the engine. You could also spin the oil pump with a priming rod and check again but if you trust your measurements just fire it up. ------------- You can’t change the wind but you can adjust your sails |
Posted By: Jllogan
Date Posted: February-15-2012 at 11:55am
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no these are not new lifters. There was a little inconsistency, they were mostly .060 a few .030. No double shimming yet anyway I only got one side done. The intake is on so no oiling them now.
So if they are too loose they will clatter/ make noise? How will I know. I know my measurements are consistent I was using a straight edge etc and I made sure both valves were closed all the way. I had one rod with no preload, it was the same before and after I torqued down the rocker. I guess I will need a longer pushtube. ------------- http://correctcraftfan.com/diaries/details.asp?ID=5792&sort=&pagenum=1" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: Waterdog
Date Posted: February-15-2012 at 12:37pm
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The one with no pre-load, maybe a collapsed lifter? ------------- - waterdog - http://www.correctcraftfan.com/diaries/details.asp?ID=3896&sort=&pagenum=2&yrstart=1978&yrend=1978" rel="nofollow - 78 Ski Tique |
Posted By: Jllogan
Date Posted: February-15-2012 at 12:56pm
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well it goes up and down fine. ------------- http://correctcraftfan.com/diaries/details.asp?ID=5792&sort=&pagenum=1" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: 81nautique
Date Posted: February-15-2012 at 1:17pm
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all I'm suggesting is that if you had to shim that much than when you tightened then down the first time and took your measurements without any oil pressure in the engine you may have pumped the oil out of the lifter. Again if you trust your readings fire it up, worst case is you have some lifter noise and you need to repeat the procedure. Once you pump the lifter out the plunger will still return to the top but it's hard to get a good read on them because they are soft until oil pressure returns.
This is fairly simple so don't overthink it, I would fire it up and you'll know right away. If you've shimmed all worse case is you'll have a little noise, too tight and you'll have a bad idle but I don't think that will be the case. If you're not sure just check them again after you run the engine a few minutes. I also don't like the scratch and measure deal so I use a dial indicator with a magnetic base and get real numbers. ------------- You can’t change the wind but you can adjust your sails |
Posted By: Jllogan
Date Posted: February-15-2012 at 1:21pm
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good advice alan,
Ill push on then, just wanted to make sure I wasnt making a big mistake. I will say that is probably what happened as they were stiff at first but after some turning over and what not things got real loosey goosey. ------------- http://correctcraftfan.com/diaries/details.asp?ID=5792&sort=&pagenum=1" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: 81nautique
Date Posted: February-15-2012 at 1:52pm
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This is why I love stud mount adjustable rockers!
By the way a quick tip for finding tdc on all cylinder and the way I do mine is to get the motor on TDC of #1 on the compression stroke. Then mark the balancer with chalk or white toe nail polish if that's your bag at 90 degree intervals. Measure your pushrod length at #1, then rotate the motor in it's correct direction 90 degress or a 1/4 turn to the mark on the balancer. Go to your next cylnder in the firing order and that cylinder will be at TDC, do this 6 more times through the firing order and your done. ------------- You can’t change the wind but you can adjust your sails |
Posted By: Jllogan
Date Posted: February-15-2012 at 1:55pm
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ahh very clever good advice. Thanks!, I just kept cranking and watching the valves open and close to figure out where they were, probably the hard/long way. ------------- http://correctcraftfan.com/diaries/details.asp?ID=5792&sort=&pagenum=1" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: eric lavine
Date Posted: February-15-2012 at 9:08pm
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i always like to keep the cordless drill in the distributor hole to keep pumping up the lifters, its a 5/16's hex to prime the pump, pretty much a sure hit so the lifters dont bleed down, even though they really shouldnt ------------- "the things you own will start to own you" |
Posted By: Jllogan
Date Posted: February-16-2012 at 12:29pm
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good thinking eric, since my engine was apart there is no oil at all in these lifters so thats probably why they bled down. Also I turned it over several times. probably should get some oil back in there. ------------- http://correctcraftfan.com/diaries/details.asp?ID=5792&sort=&pagenum=1" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: slmskrs
Date Posted: February-16-2012 at 4:52pm
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Okay, so I'm a number of steps behind and I'll need to read through the procedure several times as I don't yet know where the shims go, where you are measuring, etc. So I'm sure I'll be asking lots of questions.
But, can someone please explain to me about the drill in the distributor hole and how to pump oil that way? First, I want to make sure the lifters are all full when I do my measurements and adjustments (shims as needed), and secondly, if this is somehow running the oil pump and I can pump oil through the engine while off, that would be great (I could do that just before reinstalling the distributor and firing it up). ------------- Gordon '97 Ski Nautique, GT40 |
Posted By: 81nautique
Date Posted: February-16-2012 at 5:11pm
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slmskrs,
This is what you want http://www.summitracing.com/parts/SUM-901012/ - oil primer You attach it to a drill and place it into the distributor shaft hole, spin with a drill and it pumps oil through the engine. Go slow at first because you can send oil flying with a fast drill, you don't need much rpm to get the oil moving. Yes it is used for the exact reason you suggested, pumping oil through the engine before a cold startup. Doesn't matter if the engine is new or just hasn't been run in a while the purpose is the same. ------------- You can’t change the wind but you can adjust your sails |
Posted By: slmskrs
Date Posted: February-16-2012 at 5:25pm
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Thanks. Ordered. How does it work? Is it turning the oil pump (don't know how that is possible)? ------------- Gordon '97 Ski Nautique, GT40 |
Posted By: eric lavine
Date Posted: February-16-2012 at 5:26pm
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if you dont want to purchase one, you can use a long 1/4' extension with a deep well 5/16th's socket electrical taped to the extension. the extension will chuck up in the drill ------------- "the things you own will start to own you" |
Posted By: 81nautique
Date Posted: February-16-2012 at 5:34pm
When you get it compare it to the base of the dist shaft below the gear and you'll see it's same. It simply drops into the top of the oil pump in place of the dist. (you'll feel it drop in and engage)and you turn it with the drill so YES you are spinning the pump without turning the motor over. ------------- You can’t change the wind but you can adjust your sails |
slmskrs wrote:Posted By: Bri892001
Date Posted: February-16-2012 at 5:34pm
Normally the camshaft turns the distributor shaft, which in turn, turns the oil pump. Now, with this distributor out, you are putting in this tool, and attaching it to the oil pump, where the distributor shaft normally goes. And, instead of the camshaft spinning the distributor shaft, your drill is spinning the tool, which will turn the pump. It's kind of like when someone has a cardiac arrest, and the surgeon reaches into the chest cavity and squeezes the heart by hand to make it pump 
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Posted By: Jllogan
Date Posted: February-16-2012 at 6:02pm
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hahah what an analogy!!!
the shims go under the rockers to lift them up, this relieves some of the tension from the lifters when the valves are shut. Just google rocker arm adjustments or preload and read up on the idea. You dont want too much or too little. ------------- http://correctcraftfan.com/diaries/details.asp?ID=5792&sort=&pagenum=1" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: slmskrs
Date Posted: February-16-2012 at 6:13pm
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Aha! Now I get it (I didn't realize the pump was rotated by the distributor). What direction does it rotate (does the drill go clockwise or counter clockwise?). With right hand rotation engine (looking at the front of the engine and facing the stern), which way is the drill supposed to turn?
And on using shims, what part of using shims makes this non-adjustable? I would think that non-adjustable would mean they are auto setting, etc. and you shouldn't have to do anything. Instead, it just seems to be a painful way to adjust.... ------------- Gordon '97 Ski Nautique, GT40 |
Posted By: Bri892001
Date Posted: February-16-2012 at 6:37pm
| Actually, no matter what the rotation of your engine, RH or LH your distributor will turn the same way, which is.... hold on, I got to find that, it just came up recently. |
Posted By: Bri892001
Date Posted: February-16-2012 at 6:41pm
| Ok, just found it. As viewed from the top, the distributor always turns counter-clockwise. |
Posted By: slmskrs
Date Posted: February-16-2012 at 7:53pm
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Thanks for checking. So I now know to run the drill in reverse. :-)
I'll ask later how the distributor only turns one way regardless of crank rotation..... I saw that before but don't know why (just like I didn't know the distributor turns the oil pump....). ------------- Gordon '97 Ski Nautique, GT40 |
Posted By: 8122pbrainard
Date Posted: February-16-2012 at 8:50pm
Left or right hand gears on the cam shaft. It's also why you need the proper gear on the distributor to match the rotation of the engine. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: Jllogan
Date Posted: February-17-2012 at 12:54pm
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also the reason they are non adjustable is because once they are set they are set the only way to decrease preload is to shim or get shorter rod, only way to increase is to get longer rod. if everything was 100% new hypothetically you shouldnt need shims just bolt them on. The problem is when you get remanufacter things etc, they grind down the heads etc so that makes the distance between the lifter and the rocker shorter, increasing preload, thats why you often have to shim.
The adjustable rockers have a stud and nut you torque down. Its a little tricky at first but now that I have done it got some good advice its no big deal. ------------- http://correctcraftfan.com/diaries/details.asp?ID=5792&sort=&pagenum=1" rel="nofollow - 1986 Ski Nautique 2001 |
Posted By: slmskrs
Date Posted: February-18-2012 at 3:39pm
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Okay, I'll be bolting on the new heads today so this is next. A few questions (I've read the other references (Crane and Comp) as well as what is in the manual. Honestly, if I had read this in more detail before tearing into the engine, I would have thought twice and maybe had someone else do it. The only other car I've adjusted the valves was my first car (anyone remember Datsun), a 4-banger with adjustable valves. These non-adjustable rockers seem to be a major pain, and if I do it wrong, I can't just pop the valve covers, I have to take the exhaust manifolds back off as well as the plenum. My retired auto mechanic friend (ski club member) thinks I shouldn't have to worry about it (it will be fine without shims or different push rods (even though I said that since these are remanufactured heads and some has been milled (he says probably no more than 10 thous). I haven't seen what the shims look like, but the method of measuring seems inexact at best. I don't have a dial gauge. So, questions:
1. What do you use to scribe a small enough mark on the push rods so you can see and measure the difference? 2. Can I measure the difference with calipers (I assume I can get to the marks with them but haven't tried yet (standard calipers used for ski fin adjustments)? 3. Some of the docs I read said that you need to let the lifters bleed out before measurements, but above in this thread people were talking about collapsed lifters due to no oil so needing to pump them back up (or put them in a can of oil). I'm not planning on taking my lifters out so was going to use the drill oil pump driver to pump everything up (which I just got yesterday). Now I don't know which is the correct method. Anyway, I'm nervous about the preload measurements / adjustments at the moment. I still have to finish cleaning the head mating surfaces of the block (that's going slow) and put the heads on first. So I have a little time to continue to worry about valve adjustments (in addition to concerns about having to tear back into it again due to leaky gaskets or some dumb mistake). I think I'd better take a breather so I'm going to run out and get a ski ride in with a ski buddy (which will get me pumped up to get back onto it---and by that time, you guys will have given me a bunch of additional info and/or slapped me upside the head...... :-) ------------- Gordon '97 Ski Nautique, GT40 |
Posted By: Dizzwah
Date Posted: April-14-2015 at 10:36am
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How did you go with the preload adjustments? Reason I ask is that I too was installing some (reconditioned) GT-40P heads last weekend and I used the dial indicator method (which is different to the crane cams and OEM service manual). What had my buddy and I scratching our heads a little was the variability in time it took for the lifters to bleed down and get an accurate reading. We did all the Intakes valves by turning the engine until the Exhaust just began to move and then tightening the Intake bolt by finger until the pushrod began to not spin freely. We set up the dial indicator, torqued to spec and waited anywhere from 5 sec to 5 mins for the lifter to bleed down. Our initial concern was that the soft lifters were bad, as after doing all the intakes some of the first few felt very sloppy. But after turning the oil pump they all came back rock solid. Is the variability in bleed down common/acceptable? How do I know if I have a bad lifter? It didn’t seem to correlate with any particular cylinder or location (as I thought maybe the oil had drained from the higher ones first). Some threads say to prime the oil system first, others (like the comps) say not to as it takes longer to bleed down to get an accurate reading (I'd still be in the garage). On the hard lifters, after torqueing they might compress 3-5 thou, then after 5 mins they are at 90-100 thou. The soft ones compressed immediately and stayed steady. Does it matter that they were inconsistent? ------------- '93 Sport Nautique - from dismantling comes true understanding - |
Posted By: TRBenj
Date Posted: April-14-2015 at 11:10am
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Please re-read this entire thread from the beginning, I think you may be missing the point of the exercise. You do NOT want the lifters to bleed down while measuring preload. A good before/after comparison depends on the lifters staying pumped up. What changes is the rockers. For a non-adjustable valve train: 1. Install primed lifters, pushrods and torque down rockers to spec. 2. Make a mark on the pushrods relative to some fixed reference point (cam must be on base circle, ie, valve closed) 3. Remove rockers and see how much the (primed) lifter pushes it back up. Re-mark pushrod relative to the same reference point. 4. Measure difference between marks. If not in spec (.020-.040), shim or adjust pushrod length as necessary. |
Posted By: slmskrs
Date Posted: April-14-2015 at 3:53pm
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That is way too hard of a process. Take a look at my post in this thread: http://www.correctcraftfan.com/forum/forum_posts.asp?TID=25151&title=pushrods-shimming I documented the completed head replacement procedure; if you're interested, email me and I'll send it to you. The pushrod process I used is VERY fast and worked flawlessly. I've put several hundred hours on the heads since the replacement and it works perfectly. Gordon ------------- Gordon '97 Ski Nautique, GT40 |
Posted By: Dizzwah
Date Posted: April-14-2015 at 8:50pm
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OK, fair call. After re-reading the Comp cams and Crane cams guide I think I had it arse backwards.  The method is to torque all bolts first and then "wait a few minutes, allowing the lifters to bleed down". Then measure the preload by loosening the bolt and allowing the rod to rise. I was going from a raised position and torquing down...therefore having to wait for each lifter to bleed to neutral position. Sometimes you just get too wrapped up and can't see the obvious. Thanks Gordon, some tips in there should help me shave a few hours off the task  ------------- '93 Sport Nautique - from dismantling comes true understanding - |
Posted By: slmskrs
Date Posted: April-14-2015 at 10:31pm
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Dizzwah, I sent you a private message with my step by step that I wrote up when I replaced my heads. Sounds like you are close to being done so may not be of much help. But sent it just in case. ------------- Gordon '97 Ski Nautique, GT40 |