WASyL

hi,

i do need a bit of help. there is an engine:
- 350 stock bottom l-82
- trickflow intake
- 750cfm carb
- 3500 stall converter
- th350 trans
- stronger valve springs
- stock 1.5 ratio rocker arms
- elgin cam e-1165-p:



problem is that stock pushrod begin to bent and finally brake in to pieces mostly on intake side, are stock ones are to week and i need chromoly .080 thick ones ? or i should start to look for other problem ? i have already checked that valves do not hit pistons.

best regards

sofakingdom

iTrader: (1)

What a horrible cam. A generic copy of generically copied copies of generic copies of generically copied copies of generic cam copies from 40 years ago, made and/or sold by every cam mfr in the US except the ones that make "state of the art" cams.

http://www.summitracing.com/parts/sum-1107 for example

You might want to look into getting a decent cam while you have it apart.

Apart from that:

Your problem isn't the push rods themselves; just like, blowing a fuse doesn't mean that your fuse isn't good enough.

More likely, your springs are inadequate (reaching coil bind), or the retainers are hitting the top of the valve guides.

Changing the push rods won't fix it. If you put in strong enough ones that they don't break without taking care of the underlying problem, the only thing that will happen is, something more expensive and harder to fix will break instead. Gotta fix the interference problem.

WASyL

cam will stay in that engine so i need to find solution to this problem. that retainer hitting valve guides might be the thing cause some valve seals are damaged too.
any tips how to chceck what is the problem ?

on monday i can give springs spec.

best regards

sofakingdom

iTrader: (1)

That's truly a shame.

But it doesn't matter, to the issue at hand; a better cam would probably create the same problem, only worse.

If valve seals are damaged, then you've found a SERIOUS problem. Clearly the retainers are hitting the top of the valve guides. There are several possible solutions: longer valves or offset keepers, either of which will require changing the valve spring shims to keep the pressures correct; or machining the guides down.

The springs may still be inadequate though. What part # are they? What is their ACTUAL MEASURED installed height? How much clearance do you have between the coils at full lift?

WASyL

i'll provide this info on monday, thanks for help

best regards

big hammer

if you were bottoming out your springs, there's a good chance that your cam is toast anyway.

RBob

iTrader: (1)

Good possibility that is too much lift for the stock rocker arms. They are bottoming in the slot. If the heads had pressed in studs they would likely be being pulled out.

With the screw in studs the push rods are the weakest link.

RBob.

AlkyIROC

Too many things can be causing the pushrods to be damaged. Pushrods are not "weak" with that setup. A thin walled pushrod with extremely high valve spring pressure can damage pushrods but that isn't your case.

1: Piston to valve clearance. Possible but unlikely with that cam.
2: Coil bind. Cam lift exceeds the compressed height of the valve springs. Valve springs are compressed to maximum and the pushrod is still trying to compress them even more. At max lift, there should be 0.060" between the coils.
3: Stock rocker arms. The slot in the rocker arms only allows so much rocker movement before the end of the slot hits the rocker stud. Alternatives are to install long slot rockers or any sort of roller rockers.
4: Rocker stud boss height. Even if the valve springs don't go into coil bind there's still the possibility that the bottom of the spring retainer is hitting on the stud boss which will damage the valve seals.

With so many things that can cause valve train damage, you need to find out which one is causing the problems. There's a lot more to doing a proper cam swap then just swapping the cam. Since you're damaging pushrods, there's a clearance issue somewhere in the valve train and changing the pushrods isn't going to fix it.

Night rider327

iTrader: (13)

Like already mentioned.. You have other probs. The pushrods are not at fault here. Something is causing this and that something is a "clearance" prob.

The things to check is already been posted. Do you have a dail caliper, spring mic, etc?

You need to check your clearance between top of guide and bottom of retainer, installed height, rocker arm slot to stud clearance.

Also clearance between pushrods and the guide hole/slot in heads/guide plates

If you have guide plates also check to see if they are true and straight. Alot of aftermarket heads has this prob and isky even makes adjustable guideplates to cure it. Cause way valves gets moved on aftermarket heads, sometimes guide plates will sit cocked sideways a tad and pushrod will bind up if thats the case.

WASyL

ok, i'll chceck thase, as for springs this is what i found on the box
install at 1.780"
1.780=115#
1.500=240#
1.250=340#
coil bind 1.150"
(98212) what would reffer to Howard springs: http://www.summitracing.com/int/part...8212/overview/

will wrong lenght pushrods cause this situation too? i'm almost sure thay i have calculated lenght properly but wil have to check that again.

best regards

Night rider327

iTrader: (13)

I wouldn't think it's the springs. I have used those same springs on many engines over the past 10 years. In fact Howards is about the only springs I buy/use anymore.

Unless some out you have them installed at 1.650" or less

sofakingdom

iTrader: (1)

No, wrong length push rods will not cause that.

It doesn't matter what the springs say on the box. What matters is, how they are installed on the heads. The box may say "install at 1.780" "; but at what height are they ACTUALLY installed? 1.80"? 1.76"?, 176"? The box doesn't know that. It is COMPLETELY under the control of the installer. Only way to know is to MEASURE. Which is why I said ACTUAL MEASURED installed height, up above; the box has no way of knowing what the installer did.

What is the ACTUAL MEASURED installed height? How much clearance do you have between the coils at full lift?

How much clearance do you have between the bottom of the retainer and the top of the valve guide at full lift?

You can replace the push rods every day, and twice on Sundays just to be sure, and they will still break EVERY DAY unless you find, identify, and take care of the interference problem that is breaking them.

And also as mentioned, you may already have more serious problems than just broken push rods, if parts have been slamming into each other; the studs may be pulled out of the heads, or the cam damaged. Inspect carefully before "assuming" everything is still OK.

redneckjoe

i ran into a batch of bad pushrods once. they kept breaking under normal driving. i bought a new set and have never had a problem since. not saying thats your problem, but it does happen.

AlkyIROC

Looking at those spring pressures, you should start with aftermarket pushrods but still need to check clearances before starting the engine. A stock valve spring has around 80 pounds on the seat with an installed height of around 1.72" but will also coil bind slightly over 0.500 lift. If the spring pockets have not been modified or extra height retainers/locks used with spring shims to obtain a 0.780" install height then I'd say your new springs are still installed at 1.72".

1.72 install - 0.488 intake lift = 1.232 at max lift.
1.232 max - 1.15 coil bind = 0.082" and that's your intake which you say you're braking.
Exhaust which has a higher lift leaves 0.062 clearance before bind.

You may not have a coil bind issue but it's really close. You still may have the bottoms of the valve retainers hitting the top of the valve guides or the slots in the rockers are hitting the rocker studs before max lift is reached.

It might be something as simple as installing +0.050 valve locks to move the install height up higher and an inexpensive set of roller rockers to keep you from damaging pushrods.

WASyL

by +0.050 valve lock you mean like these ones?

http://www.summitracing.com/int/part...1-16/overview/

are there any cheaper ones ?

as for rockers will these be ok ?
http://www.summitracing.com/int/part...make/chevrolet
heads do have guideplates and screw in studs

best regards

Night rider327

iTrader: (13)

I would not recommend those rocker arms. Too weak IMHO. Also do you have the larger 7/16" rocker studs or the common 3/8" studs? You need rockers for the stud size you have.

I buy most of my valvetrain parts through competition products. Much cheaper.

$13 +.050" 7* locks http://www.competitionproducts.com/V.../#.VEbjcfnF9QE

If you have 7/16" studs I recommed these rockers
http://www.competitionproducts.com/H.../#.VEbkyfnF9QE
I use those myself with .570"/.579" lift cam

Also these are good http://www.competitionproducts.com/H.../#.VEblGPnF9QE

And these http://www.competitionproducts.com/S.../#.VEblMvnF9QE

AlkyIROC

I don't know the diameter of your valve stems but any 7* locks designed for the diameter of the stems that you use will work fine. I thought SBC stems were 3/8"? Maybe it was 5/16". 5/16" locks are not 8mm locks. If you want to switch to better 10* locks, you'll also need to replace the retainers that are designed for the 10* locks.

Those roller rockers are inexpensive and will work but not that exact set. There are other better choices. As mentioned above, you also need to use a set for a 3/8" rocker stud which is probably what you have. 7/16" rocker studs are not OEM. If you had heavy valve springs with around 600# of open pressure, you would consider switching to 7/16" studs and rockers.

A lot of my valve train is Comp Cams components. Springs, retainers, locks, shims, locators and pushrods. I use T&D shaft rockers which is well out of your budget. The set I have is actually sold by Comp Cams but is made by T&D.

sofakingdom

iTrader: (1)

SBC stems are 11/32". Not 3/8", not 5/16", not 8mm, not 9mm. (usually given as .3437" or .3438", or about 8.731mm)

Night rider327

iTrader: (13)

sofakingdom is correct. The SBC valve stems are 11/32", stock and most smaller valve spring sets uses 7* retainers and locks although 10* is an option.

All stock, and most aftermarket SBC heads uses 3/8" rocker studs/rocker arms. 7/16" is an upgrade and only needed with high lift, high spring pressure, high rpm use.

The cheaper full roller alum. body rockers are scary and can fail. If they do fail they send little needle bearings through out your engine. That's why I recommend the ones I do, they are the cheapest good ones.

If you do not need or want to upgrade to a full roller rocker you can grind out the pivot slots some in your stock rocker arms to prevent rocker to stud probs, or buy elongated slot stamp steel rockers. I have used the elgin roller tip stamp steel rocker arms for many years and love them on engines with less than .515" lift

WASyL

still haven't chcecked that install height, will do following week.
But some hypothetical questions.
heads are stock L82 with 3/8 scrw in rocker arms studs, stock guideplates etc. like stock L82 heads does.

1. if AlkyIROC is right will these +0.050 locks on both int/exh fix my problems?
2. Do i need to replace rockers or can i stay with stock ones?
3. if rockers need to be changed which one cheepest i need to get?
3. any other ting i need to look in ?
4. does installing Valve stem seals ss72527 both on int and exh is a good idea or not?

best regards

sofakingdom

iTrader: (1)

Don't worry about any of that yet.

MEASURE your parts.

Then, you'll KNOW where the problem is.

Until then, there is no sense whatsoever into getting yourself into a game of "maybe it's this, maybe it's that, could it be this over here?". That's the way intellectually weak people fail. Don't be one of <contempt> them </contempt>.

AlkyIROC

1: Depends what the current install height actually is. The +0.050 locks are to help adjust tolerances. Shims under the springs can help reduce the install height if the locks increase it too much. There is no simple answer since just swapping out stuff isn't setting up the heads properly.

2: Probably need something different. Stock stamped steel rockers are good for stock cams.

3: Whatever your budget will allow. Any full roller rocker will do but inexpensive does not mean you'll be happy with them.

3?: Since you did a lot of changes, valvetrain geometry should be checked to make sure your pushrods are the correct length.

4: For a street car, valve stems on all the valves are a good idea but realistically, they're only needed on the intake valves. There's never a vacuum under the exhaust valve to suck oil down the valve guide.

Night rider327

iTrader: (13)

You have to measure your parts. Know what to know for sure with out. To play along with your hypothetical game though..

1) Yes, the .050" locks will move the retainer .050" higher up and you will not have retainer to guide probs, coil bind, etc

2) Yes. You have a big cam. Big cams, big valvetrain events do not play well with stock parts. The slot in stock rocker arms are short and will bind on studs with as little as .480" lift

3) Only a rich man can afford cheap parts.. Cheap parts will fail and when failure happens more will get damaged than just the rockers.
I have a proform brand stamp steel roller tip rocker next to me right here than the roller tip broke off of with a .464"/.482" lift cam. Google roller rocker failures and you will see many stories of broke cheap alum. body full roller rockers.

I have ran these myself and feel good recommending them. This is the cheapest I would ever go with http://www.competitionproducts.com/E.../#.VEyDbvnF9QE As you can see they are stamp steel roller tip, not full rollers. I ran a set of those for 6 years with a .484"/.512" lift cam. Then upgraded my combo and gave those to my dad and he has been using them for 4 or 5 years now with about the same lift.

If you want a full roller, alum body rocker.. The cheapest will be $240 http://www.competitionproducts.com/H.../#.VEyEBfnF9QE

Next up $250 http://www.competitionproducts.com/S.../#.VEyEEPnF9QE

Then, the ones I use and recommend $280 http://www.competitionproducts.com/H.../#.VEyEC_nF9QE

4) Like already mentioned check pushrod length, check pushrod to guide plate clearance. If using guide plates make sure you use hardened pushrods as the guide plates will cut through non hardened ones.

5) Yes I would use those seals on both intake and exhaust valves

WASyL

ok from what i have measured with this manual:
my measurements are:
exh 1,700"
int 1,728"
what lock do i need?

and does removing these cups (see pic below, white arrows showing) do any better in this sittuation? they are 0,035"


best regards

AlkyIROC

Those "cups" are to control oil splash. Rarely if ever used with aftermarket springs and yes, they can help get more install height if removed since the spring will press against the retainer and not the underside of the cup.

WASyL

so if i remove splash cups and add + 0.050 lock i will get 1,785exh and 1,813int will that be ok ?

as for rocker arms i want to get these:
http://www.summitracing.com/int/parts/hrs-90070
locks:
http://www.summitracing.com/int/parts/tfs-52400445
and pushrods (from trickflow propably) after chcecking lenght

is that ok ?

best regards

James Sutton

iTrader: (2)

Mine were breaking. Turned out I had covers with metal baffles instead of rubber. Push rods were bumping into the baffles. Installed correct baffles and new push rods, and problem is gone.