Why would my motor keep bending and braking pushrods? Its a SBC with a hydrolic cam, heat treated push rods because I have guide plates. And vortec heads. I had to buy +.150 push rods because the rockers would bottom out on the screw in studs with a stock length pushrod. Oil will flow up the push rod just fine so I dont think it is an alignment problem. When I adjusted the rockers I went till the pushrod would not spin anymore and then turned 1/2 turn. Is this right?
I dont. The highest this thing has ever seen is 4 1/2 5 thousand RPM. Its such a light car I dont even touch the throttle hardly and the tires bark.
The Vortec head, as stock, has a limited amount of cam lift capability. Are you sure that your cam is a compatiable with the heads?
I think your method is fine for start up , but I do them again , running . Back off till noisy tight till quiet and half a turn ....Yes its messy , if you have some old rocker covers you can cut the top out .
They are aftermarket heads with big valves but stock runners. They have screw in studs and guide plates. They are rated at .500 lift and I know the cam is under that. Its a mild lunati cam. I think .460-.480. Idle is just barely choppy, lots of va***e. I will check but Im sure there isnt anything touching when the rocker moves through its strokes.
I was thinking that my lifters were going because my rockers seam to loosen up. Not allot just a little slop. Should the rockers always have tension? Should I be able to wiggle them side to side?
The rocker stud bosses might not be cut down far enough and along with the over sized push rods may be causing the slot in the bottom of the rockers to bottom out on the stud at high rpm.
Did you check the length of the push rods to make sure they are not to long ? Also are you using heavier springs ? Did you change the rocker ratio ?
Stock rockers, heavier springs yes. I have a set of roller rockers I bought for the new motor that I can throw on here and try. What is too long mean? What do I look for?
The stock stamped rockers have a narrow slot and with what I mentioned earlier are most likely in a bind if the rocker geometry is way out of whack. The rollers will probably have enough travel to work but the tips may not ride in the center of the valve. Were your heads meant to have guide plates or did you add them? I believe the Vortecs use a self guided rocker and not a guide plate to center the rocker.
Push rod length should be determined by the contact on the valve, by that I mean the contact area should be centered on the valve tip. As the valve opens and closes the rocker arm goes through an arc causing the tip of the rocker to wipe across the valve tip, the average of this motion should be centered. The reason you gave for buying longer pushrods is foreign to me. Another point brought up already, Guide plates, If the heads were stock they might have come with self aligning rockers and round holes for clearance where the pushrod p***es through the head casting. The other possibility would be that they didn't come with self aligning rockers and would have had a tight slot where the pushrods p*** through the head casting, in which case those holes would need to be drilled out by the machine shop that installed the guide plates. Check to make sure that was done. Scrutinize your parts and look for evidence of contact, this will help you ****yze your problem. It could possibly be wrong adjustment, especially if you depressed the plunger in the lifter too far. The static adjustment method I use involves tightening till the up and down play is taken up(not quits spinning) then another half turn. You may have them too tight. But I also suspect the geometry is thrown off by the longer pushrods. P.S. My adjustment method works for me so well that on stock motors I just go ahead and glue the valve covers on before installation.
This happened to me with a BBC. Found out the springs were not compatable with my cam choice. Some machine work and new compatable springs and never happened again. When it did happen I was doing about 2000 rpm on the freeway.
You have answers of all sorts to me. Mild cam you but you say you heavier springs than stock... Why? And most of all do you know exactly why you have longer push rods? Start there. I hear people having install problems like this alot with Vortec Heads way too much trouble. To me your parts are compatable. Figure it out.
Did you select the longer pushrod due to the aftermarket heads, or based on using a stock vortec head? Don't tighten your rockers down as much. Sounds like you might be putting too much preload on them, if as you say you tighten until you can't spin them. As soon as you feel friction then add a 1/2 turn. Alex.
you have to run self alining rockers. was the motor running fine before you changed something or is this a new build? also when your spinning the push rod with your fingers you want oil on them and lightly spin till they stop not dry fingers with a death grip spin lol
Your rockers keep getting loose. Did you break in the cam with the right oil or procedure, might be wiping lobes. I think you adjusted your lifters to tight also. Ive seen many things that can do what your explaining, some have been mentioned allready.
If this is a new build and if any work was done to the valve guides I would look there, especially if it only does it after the engine is hot. Scott...
Here is something else to considerOil is Killing our CarsBy Keith Ansell, President Foreign Parts Positively, Inc. www.ForeignPartsPos<WBR ***le=http://www.foreignpartspositively.com/>itively.com 360-882-3596 <TABLE cl***=EC_MsoNormalTable style="WIDTH: 100%" cellSpacing=10 cellPadding=0 width="100%" border=0><TBODY><TR><TD style="PADDING-RIGHT: 7.5pt; PADDING-LEFT: 7.5pt; PADDING-BOTTOM: 7.5pt; WIDTH: 100%; PADDING-TOP: 7.5pt" width="100%">Oil is Killing our cars Part I About a year ago I read about the reduction of zinc dithiophosphate (ZDDP) in the oils supplied with API approval that could affect sliding and high pressure (EP) friction in our cars. The reduction of these chemicals in supplied oil was based on the fact that zinc, manganese and/or phosphates reduce the effectiveness and eventually damage catalytic converters and introduce minute amounts of pollutants into our atmosphere. A month or so ago I had a member of the Columbia Gorge MG Club bring a totally failed camshaft and lifters back to me that had only 900 miles on them!! I immediately contacted the camshaft re-grinder and asked how this could happen. They were well aware of this problem as they were starting to have many failures of this type. In the past, the lack of a molybdenum disulfide camshaft ***embly lubricant, at ***embly, was about the only thing that could create this type of problem. My customer has ***embled many engines and had lubricated the camshaft properly and followed correct break in procedures. This got me on the phone to Delta Camshaft, one of our major suppliers. Then the bad news came out: It’s today’s “modern” API (American Petroleum Industry) approved oils that are killing our engines. Next call: To another major camshaft supplier, both stock and performance (Crane). They now have an additive for whatever oil you are using during break-in so that the camshaft and lifters won’t fail in an unreasonably short period of time. They also suggest using a diesel rated oil on flat tappet engines. Next call: To a racing oil manufacturer that we use for the race cars (Redline). Their response: “We are well aware of the problem and we still use the correct amounts of those additives in our products”. They continued to tell me they are not producing API approved oils so they don’t have to test and comply. Their oils were NOT the “new, improved and approved” ones that destroy flat tappet engines! “We just build the best lubricants possible”. Sounds stupid, doesn’t it, New-Approved but inferior products, but it seems to be true for our cars. To top this off: Our representative from a major supplier of performance and street engine parts (EPWI) stopped by to “warn us” of the problem of the NEW oils on flat tappet engines. This was a call that the representative was making only because of this problem to warn their engine builders! “The reduction of the zinc, manganese and phosphates are causing very early destruction of cams and followers”. They are recommending that, for now at least, there must be a proper oil additive put in the first oil used on new engines, beyond the liberal use of molydisulfide ***embly lube. They have been told that the first oil is the time the additives are needed but remain skeptical that the first change is all that is necessary. Their statement: Use diesel rated oils such as Delo or Rotella that are usually available at auto stores and gas stations. This problem is BIG! American Engine Rebuilder's ***ociation (AERA) Bulletin #TB2333 directly addresses this problem. I had a short discussion with their engineer and he agreed with all that I had been finding. Next phone call was to a retired engineer from Clevite, a major bearing and component manufacturer. First surprise was that he restored older British Motor bikes. The second surprise was that he was “VERY” aware of this problem because many of the old bikes had rectangular tappets that couldn’t rotate and are having a very large problem with the new oils. He has written an article for the British Bike community that verify all the “bad news” we have been finding. Comp Cams put out “#225 Tech Bulletin: Flat Tappet Camshafts”. They have both an ***embly lube and an oil additive. The telling sentence in the bulletin was “While this additive was originally developed specifically for break-in protection, subsequent testing has proven the durability benefits of its long term use. This special blend of additives promotes proper break-in and protects against premature cam and lifter failure by replacing some of the beneficial ingredients that the oil companies have been required to remove from the off the–shelf oil”. Next question: Now what do we do? From the camshaft re-grinders (DeltaCam): “Use oils rated for diesel use”, Delo (Standard Oil product) was named. About the same price as other quality petroleum based oils. They are not API formulated and have the zinc dithiophosphate we need in weights we are familiar with. From the camshaft manufacturer (Crane): “use our additive” for at least the first 500 miles. From General Motors (Chevrolet): add EOS, their oil fortifier, to your oil, it’s only about $12.00 for each oil change for an 8 ounce can (This problem seems to be something GM has known about for some time!). From Redline Oil: Use our street formulated synthetics. They have what we need! From our major oil distributor: Distributing Castro, Redline, Valvoline and Industrial oils: “After over a week of contacts we have verified that the major oil companies are aware of the problem”. “The representatives of the oil companies today are only aware of marketing programs and have no knowledge of formulation”. The only major oil companies they were aware of for doing anything to address this are Valvoline that is offering an “Off Road 20W-50” and Redline. From Castrol: We are beginning to see a pattern emerging on older cars. It may be advantageous to use a non-approved lubricant, such as oils that are Diesel rated, 4 Cycle Motorcycle oils and other specified diesel oils. Last question: So what are we at Foreign Parts Positively going to do? After much research we are switching to Redline Street rated oils and stocking the Castrol products that are diesel rated. Castrol, owned by British Petroleum, is now just a brand name. This is a difficult decision as we have been a dealer and great believer in all Castrol Products for over 40 years. We have been using Castrol Syntech oil in new engines for about 3 years so the cost difference in changing to Redline is minimal. The actual cost in operation is also less as the additive package in Redline makes a 1-year or up to 18,000 mile change recommended! Yes, it is a long change interval but with lowered sulfur levels and the elimination of lead and many other chemicals in the fuels there are less contaminants in our oil from the fuel, which is the major contributor to oil degradation. We will continue to offer the Castrol products but will now only stock the suggested diesel oils that they produce. Too many things are starting to show up on this subject and it has cost us money and time. Be aware that “New and Improved”, or even products we have been using for many years, are destroying our cars as it isn’t the same stuff we were getting even a year ago. For the cars that use “engine oil” in their gearboxes this may even pose a problem as these additives that have been removed could be very critical in gear wear. We will be using oil specifically formulated for Manual Gearboxes with Br*** Synchronizers. The only oils we are aware of that fit the criteria are from General Motors and Redline. If you have any additional input let us know. We need to let every flat tappet engine owner, i.e.: every British Car owner know that things are changing and we MUST meet the challenge. Oil is Killing our cars Part II Last month’s report on this subject is turning out to be just the tip of the iceberg! Many publications have had this subject of zinc-dialkyl-<WBR>dithiophosphate (ZDDP) covered in varying depths over the last few months. Some publications have even had conflicting stories when you compare one month’s article with their next month’s article! They are all ending up supporting our report. I have had the good fortune to have the ear of quite a few leaders in the industry including some wonderful input from Castrol. We have been very reluctant to “dump” Castrol, as it has been such a great supporter of our cars and industry over the years. Castrol hasn’t really abandoned our cars, just shifted to a more m*** marketing mode. Many Castrol products are not appropriate for our cars today, some still are. Now for the latest report: #1 Castrol GTX 20W-50 is still good for our cars after break-in! 10W-40, 10W-30 and other grades are NOT good. Absolute NOT GOOD for any oil (Any Brand) that is marked “Energy Conserving” in the API “Donut” on the bottle, these oils are so low with ZDDP or other additives that they will destroy our cams. Virtually all “Diesel” rated oils are acceptable. #2 Castrol HD 30 is a very good oil for break-in of new motors. This oil has one of the largest concentrations of ZDDP and Moly to conserve our cams and tappets. #3 Only an unusual Castrol Syntec 20W-50 approaches the levels of protection we need when we look to the better synthetic lubricants. We are attempting to get this oil but will be using Redline 10W-40 or 10W-30 as these are lighter weights for better performance, flow volume, less drag and has the additive package we need. #4 The trend today is to lighter weight oils to decrease drag, which increases mileage. Most of these seem to be the “Energy Conservation” oils that we cannot use. #5 Redline oil and others are suggesting a 3,000-mile break-in for new engines! Proper seating of rings, with today’s lubricants is taking that long to properly seal. Shifting to synthetics before that time will just burn a lot of oil and not run as well as hoped. #6 The “Energy Conservation“ trend was first lead by automakers to increase mileage numbers and secondly because the ZDDP and other chemicals degrade the catalytic converter after extended miles, increasing pollution. We don’t have catalytic converters and the mileage gains are not that significant for most of us. For you science buffs: ZDDP is a single polar molecule that is attracted to Iron based metals. The one polar end tends to “Stand” the molecule up on the metal surface that it is bonded to by heat and friction. This forms a sacrificial layer to protect the base metal of the cam and tappet from contacting each other. Only at very high pressures on a flat tappet cam is this necessary because the oil is squeezed/wiped from the surface. This high pressure is also present on the gudgeon pin (wrist pin) in diesel engines, therefore the need for ZDDP in diesel engines. Second part of the equation is Molybdenum disulfide (Moly). The moly bonds to the zinc adding an additional, very slippery, sacrificial layer to the metal. I found out that too much of the moly will create problems; lack of this material reduces the effectiveness of the ZDDP. The percentage, by weight is from .01 to .02%, not much, but necessary. Latest conclusions: Running our older, broken in engines on Castrol 20W-50 GTX is ok. Break in a new engine for 3,000 miles on HD 30 Castrol. New engines (after break-in) and fairly low mileage engines will do best with the Redline 10W- 40 or 10W-30 synthetic. - </TD></TR></TBODY></TABLE>
Are you usin' those polylock nut deals (the ones with the allen screw in the middle) to hold down your rockers? If so, I had that problem a few years ago. Picked up a trick from a guy I was talking to, he said to get those things to really stay, you have to turn in the set screw and then give the whole nut another little nudge tighter... I'd give it about 3/8 a turn, tighten the set screw down, then give it another 1/8 bump. Never had a problem after I started doin' it that way.
Ok, I have a good base to go out and trouble shoot. I will throw the roller rockers on to make sure the slot is the problem. I will change my instalation prosses too. And they have locks. When I built the motor I bought new aftermarket heads from RHS. Vortec heads with screw in studs, guide plates .500 lift springs, 2.02/1.60 valves and 64cc chambers. I installed them on a fresh stock bottom end. I went to install the rockers and they went all the way down and bottomed out on the bottom of the stud. So I had to buy longer pushrods. I heard that this was normal putting vortec heads on an older block. Do I have to pump up the lifters before I install the rockers maybe? I spin the pushrod between my fingers while tightening my rocker down. When I cant spin it anymore I turn 1/2 turn down and go to the next cylinder(TDC). Should the rockers be a little loose when Im done? I though that the nuts holding the rockers down were comming loose. because they seam to loosen up after running. I used the lube that came with the cam when I put it in. I have driven the car alot but this is the third pushrod I have either bent or broken. the only wear I see is the sides of the pushrods were they rub on the guide plates and its just rubbed the black off. not gouging or real wear.
Sounds like you're over tightening them... You want to still be able to spin the pushrod before you give it the extra 1/2 turn, you just don't want it to be all loose in there. Essentially you're taking all the slack out with that, then the extra 1/2 turn preloads the spring in the lifter. Things shouldn't really be loose when you're done... At least not that I remember, the only engines I've worked on lately are my flathead (no rockers) and my FE (shaft rockers), so they're a little atypical. But since you're preloading that spring, it should be pushing back up on the pushrod, which should make things pretty snug.
To add to that, I was bendin' pushrods like crazy in 351C before I learned the torquing trick thing... The rockers were coming loose so the pushrod was sorta jackhammering the rocker. And 351C's use the Chevy-style rocker setup (you can actually use BBC rockers on a 351C, alot of the ones you buy ARE just BBC rockers, that's why I ran Harland Sharps, they were 351C-specific).
When I had a similar problem it was the cam itself. It wore unevenly and then one pushrod would wander and push at an angle till it bent. Repeatedly.
are they self aligning roller rockers you need these check out the tip http://www.jegs.com/i/Proform/778/66914/10002/-1 unless yours were converted
Self aligning rockers have a groove that the valve tip rides in, and not your problem with the guide plates. When you adjust your lifters all you do is a small prelode and then adjust. the finger spin deal is not really telling you anything. I would back off all your rockers and start fresh. I adjust to the base circle on one cylinder , turn the nut down untill the rocker and pushrod just start to move. Then a half to one turn after that should be good. Do that to all of them and then start it and see if they make noise after running for 5 min.
I doubt the valve adjustment was the problem in the first place and this suggestion sounds a little dangerous, sorry. Spinning the push rods between the fingers and feeling for a slight drag is the generally accepted method and watching for some movement would be far from accurate considering you are only preloading the lifter about .020" with the additional 1/2 to 1 turn after 0 lash.
Also with a hydraulic cam when the rockers are adjusted correctly and the lifter is on the base circle the rocker will feel a little loose but there shouldn't be any play in the push rod just the movement of the spring loaded plunger in the lifter being that there is no oil pressure keeping things solid. Another issue I've seen with RHS heads has been rocker stud bosses drilled off center causing 1 or more of the push rods on each head to bind on the runners but it was with the Pro Action versions not a Vortec head.
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