Sonix

iTrader: (1)

I'm building up my 350 now. I'm tightening my rocker arms, and the rocker arm bottomed out at the bottom of the rocker stud before getting sufficiently tight.

Specs:

-350 chev, bored and whatnot
-Isky Z25 solid flat tappet cam. Regular base circle. Normal crane solid lifters
-block is decked about .010". Steel shim gasket. .015" measured deck height.
-416 heads, decked a smidge for flatness. Maybe .005" or so. Stock headbolts. Pushrod slots drilled out 1/2".
- Mr gasket 1076 collarless thread in rocker studs
- El cheapo SA rockers. Normal stock stamped, 1.5 ratio. stock rocker nuts.


Pics are attached. First pic shows #1 exhaust, and how it's completely down at the bottom where the "collar" is. I tightened these down with a .018" feeler gauge above the valve stem, until it was just 'tight' on the feeler gauge. I didn't even notice on that one. I went on to the next one (purely using the EOIC method) so I ended up at #5 intake I think it was, and that's when I noticed I couldn't get to 'snug' on the .018" feeler gauge, and I figured out why. I threw on my cheesy pushrod length checker, and to me that shows the pushrod is a bit too tall, lets call it .080" or so. That's just a side note though.

My calipers are only 6", so my pushrods are approximately 7.8" (measuring tape). They are stock SBC pushrods, crane 3 piece IIRC.

This engine ran fine, and didn't have this problem last year. Changes include:

composite -> shim gasket (call it a .020" difference at best)
camshaft and lifters -> compxe268h to isky z-25
bearings, gaskets, rings, etc.

I know this is probably an obvious one, but i'm really scratching my head on this. Longer valves and pushrods don't make sense since it was fine before.

Thanks

wanta427

Did you just get the heads tapped for the screw in studs? You're calling them collarless studs but it looks like the rocker arm is bottomed on the collar . The other pic with your pushrod checker shows the stud on the exhaust valve sitting way higher than normal pressed studs . I'd say pull the heads off and get the seat for the rocker arm studs machined .100 or so to get your clearance back . I had one of those studs in the garage and checked it against a stock press in stud and the length of the stud is the same to the collar so the collar has taken all your clearance . The pushrod checker shows you could use a longer pushrod but wait and see where the rocker arm travels on the valve . If it's not running off the edge of the valve running centered) it will probably be OK . Roller rockers would be more critical .

Sonix

iTrader: (1)

No, I pulled the studs and tapped them for screw in studs back in the day.

These rockers are just for break in, after that i'll be running 1.6 roller tips.

They call them collarless because they don't have the hex flat there for tightening. They do have this "nub", maybe 1/8" tall, just to seat on the the rocker boss.
You're right though, they are the same height. So then my question is - if I was still running normal rocker studs, should I be at 1/8" clearance there? Is this tiny nub what's ruining my day?

vipershark11

iTrader: (6)

funny thing is i did the exact same thing as you except im using 50/50 1.5 exhaust 1.6 intake but same studs and such. my problem is the damn studs keep unscrewing when i adjust the valves and back them off. other than that my rocker sit about that collar. check spring height and make sure the pushrod length is right too.

Sonix

iTrader: (1)

Yea, mine unscrewed a few times. I filled the rocker void in the intake ports with epoxy, so I can skip the sealant on some, and switch to red loctite. Also, I put a pipe wrench on the smooth part of it and TIGHTENED it down. And i've had them hottanked since, so I think they're pretty well in there now.

Your rockers sit above that collar? How far, what at TDC, or do you remember?

Spring height is nominal, 1.85" or so. I have .050" offset locks on the exhaust. But that shouldn't do anything, since the rocker only touches the top of the valve itself, and that height is set by valve length, and how deep the valves were cut. Pushrods are stock 7.8" length.

This cam has less overall lift than my previous two, so i'm guessing the base circle is LARGER, so the pushrod should be higher all around. I'm assuimg these solid tappets are the same height as hydraulics.

Hmm, I think I just may have to remove the valve train, remove the studs, tape off the engine and touch the bosses with my grinder. D'argh.

F-BIRD'88

Put your roller rockers on and check geometry.

Should have just drilled and pinned the rocker studs.

Push rods appear way too short.
Spring retainer height should be 1.70" to 1.75"

Possible small base circle cam.

Possible wrong lifters in the right lifter box. Non standard push rod seat height.
An .842" solid lifter but not for a SBC. A hydraulic lifter? Check push rod seat on the lifter to see if it compresses or is solid.

Compare push rod seat height to a known lifter (old hyd lifter ok)
look a the pics of my valvetrain. notice the rocker arm nuts. Notice how high the rocker sits on the rocker stud. Stock pushrods, stock rockers.

F-BIRD'88

rocker nuts

My money is on the lifters being the wrong ones.

Sonix

iTrader: (1)

I was going to post two weeks ago saying that they sent me hydraulics instead of solids. They looked just like hydraulics.
I expected them to look like this
http://store.summitracing.com/partde...6&autoview=sku
(not exactly as pictured though...)

I couldn't push the pushrod seat down with my hand, so i'm pretty sure it's a solid. Box p/n was right. They could only be a hair off size in order to fit in that box anyway. They looked the right size (height). Cam looked right size as well.

I couldn't see much on that first picture ? I figured it should sit higher, but I couldn't remember from before. Lifters sit in the bores the same as hydraulics. I figured a small base circle cam or different lifters would be visibly different.

I think for my own comfort level i'll remove the intake and check the lifters here. I'll post back with that info. If they're ok then i'll be grinding the rocker boss down.

Spring height is so high because I didn't put any shims in there. Super light spring force for break in. I'm going to be shimming it up .1" or thereabouts on each side, after break in.

F-BIRD'88

I'm refering to the height of the lifter pushrod seat in the lifter, not the length of the lifter body. compare it to another SBC lifter. I have new comp SBC solid lifters here. Can compare lifter plunger (pushrod seat height in the lifter body.

Sonix

iTrader: (1)

Yea, gotcha.

Ok, had a hydraulic from my xe268, compared height. I just measured from the top, down to a flat spot, since the pushrod "cup" isn't flat enough to get a reliable measurement.
The new solid is ~.030" further down. I don't think that's enough to make a whole lot of difference.

So today I removed all the rocker studs, and ground the bosses down with the ol' angle grinder. Took them down ~.150". Put the studs back in. Now i'm rechecking lash here.
Looks like the rocker-stud 'collar' clearance is ok, but the pushrods are much too short. Looks like the rocker is going to hit the back of the stud. I can elongate it, or I can get longer pushrods.
I have 7.8" stock ones, and I bought a pushrod length checker. I'm going back to my garage right now to scope it out a bit more.

I tried it earlier today and 8.0" seemed to work pretty good, but I thought .200" was a big difference. I went shorter and shorter and checked the marking using a sharpie. I couldn't really tell much of a difference. I was checking it with my 1.6 roller tips that I will be using later.
PS - CNC motorsports rocker arms that are ~$80 are very nice pieces.

I'm going to lash a valve correctly here, (EOIC) to zero lash, then do up a witness mark, and size up a pushrod. Will post back findings.

AlkyIROC

Why? Just install the roller tip rockers.

Looking at that rocker, it's a self aligning rocker. How much difference will a normal rocker or a roller tip rocker increase the installed height?

If it's a hydraulic lifter, once you get zero lash, you can keep tightening the rocker and the pushrod will push into the lifter. If it's a hydraulic lifter, once you get zero lash, you can keep tightening the rocker and the valve will open.

Sonix

iTrader: (1)

It's a solid lifter. oh, I see what you mean though Stephen, a hydraulic will be tightened more than just to the cup. So ok, it's probably the same.

Yea yea, I should have drilled and pinned the rocker studs. That info doesn't help me now though does it?? Hindsight is always 20/20.
I tried drilling the studs on my practice 993 heads, and I couldn't get through the case hardened studs, so I decided to use threaded ones instead - and the rest is history eh?

Some history;
I elongated the pushrod slots to accept my 1.6 RR last year. I had 1.6 non-SA roller tip rockers, and the compxe268. I kept breaking a pushrod. (twice). Then I figured out it had worn a slight part in the slot, so it went off to the side, got stuck, and broke. The cam was fine though *whew*. Because of that, I drilled the slot out to 1/2", and grabbed SA rockers. I grabbed el-cheapo 1.5 normal rockers to get the car running. That's what i've got on there now.
A few months ago I noticed CNC had cheaper 1.6 SA roller tip rockers, less than $100 IIRC. I grabbed those.

For break-in I want to give this engine as much of a fighting chance as I can. That's why the low ratio rocker arms and no shims under the springs.
Ok, going to the garage now for real, to check the witness mark and spec out some pushrods.

Sonix

iTrader: (1)

Ok, so Stephen may have been on to something.
I've attached a pic of my 1.5 stock replacement rocker, and my high performance aftermarket one. Yea, the stock one had such a narrow slot, that any more than stock lift and it's dicey. I could have made it work, but I'd need a very exact pushrod length to keep it centered in the rocker slot.

So, with my nice 1.6 roller tips, any pushrod length would work.
Stock will work, but isn't quite ideal. I think .050" taller would be best, so i'll see if I can find that length for a reasonable price.
I set up my adjustable pushrod checker with my ruler (so i'm about 1/16" accurate) and tried it. I took pictures of each witness mark at each location, but I didn't realize a feature called "digital macro" until the end Normal macro just would NOT focus on it at all! Anyway, I went all the way up to 8", and by that point the witness mark was way over at the end. Just a hair longer than stock seemed to be best as far as looking right from a side view, and most narrow witness mark.

With a sharpie and roller tips it isn't ideal though. Is there an easier method? I'm going to break in the engine on the stand with the stock pushrods, then tackle checking for an ideal length down the road. I need this car running for next weekend so...

Thanks for all the ideas guys

Supervisor42

A thin layer of dark colored moly-sulfide chassis grease also works well.
A side note for future searchers:
Notice how Sonix is actually measuring and checking things and not simply bolting stuff together and wondering why it doesn't run right.
This is what's required to build a high-perf engine that doesn't have problems.
You did slather the rev-lube all over the cam when it was installed, right?
If you did, it should be fine with the 1.6's and unshimmed springs.

Sonix

iTrader: (1)

Yea, I slapped together the engine last two times, but now i'm a little nervous. Good thing i'm doing it this time.

Yep, the cam came with that stuff, so I slathered it on. I used more of it on pushrod tips, lifter bottoms, rocker *****, etc.

I'll be firing it up this afternoon, here's hoping...

2oldFbody

I also have them studs no issues but just a side note.
I also put them in my dads 327 and cracked a stud boss in the
corner by the oil return. Them studs where the little shoulder is,
is a little tapered and acted as a wedge and split the stud boss.

Sonix

iTrader: (1)

Ok, I fired it up on the stand here this afternoon. Got it to run for about 3 minutes.
It stopped snowing for a bit today, so I got half a chance
I filmed it all, but it's a sh**show. It leaked oil from the oil pan, distributor seal, and it leaked coolant into the oil *somewhere*. It's like watching retards f*** here. It wouldn't fire so we were dinking with the timing and carb setup. Hard to watch. Funny, but hard to watch. I've got helpers that I need to remind "lefty loosey, righty tighty" eh?

Pretty slick setup with the garden hose and everything. We reinforced my engine stand for strength too, pretty proud of that part.

Going on a business trip this week, so next weekend i'll go back for round two.
The intake ports in the heads were clean, so I don't think any water/oil got into combustion chambers. I think just the water went into the oil.
I'm going to replace the oil pan seal with a 1 piece rubber, new intake gaskets, new distributor seal (yea, that leaked too...)

Come to think of it, the distributor, and oil pan shouldn't have leaked. Unless it was severely overfull of oil right? Now I must have poured in 6-7L of oil (normal stock replacement pan). I poured in oil, then immediately checked the level, and the dipstick was dry, so I kept adding oil until I could see it on the dipstick = 6 L or so. 1 4L jug, plus EOS, plus half another jug.

Overly full could explain the oil pan leak. But why couldn't I see it on the dipstick? Factory replacement chrome dipstick. Pressed into the block normally. Same as last years part, worked fine before.
Bigger oil filter now though, big napa (wix) one.

Hmm, points to ponder during my road trip. Let me know if anyone has any advice. 60-70psi of oil pressure while running on stand.

Thanks

AlkyIROC

I fired an engine up supported on the oil pan and 2 jack stands just to show it ran for a buyer. No exhaust manifolds. Looked cool and it sold.

I never did get around to building a run up stand although I have everything to do it.

It's a lot easier checking and repairing leaks if the engine is fired up out of the car.

Just like telling your sod layers "Green side up" or the nails with the heads on the wrong end are for the other side of the house when putting up siding.

Sonix

iTrader: (1)

Huh, you sell me this 350 Stephen? A guy down in Ogden ran this 350 on the stand for me before I bought it. Traded him a '76 Buick with running 455 for a Derby in exchange for this very 350.
Yea, i'm tired of putting it in the car and it FRIGGEN LEAKS. Been there, done that, twice. No more. It'll run like a swiss watch before it gets to go into the car now.

:rofl:

Supervisor42

Ain't having a test stand great? Which I must compliment you on. Everything looks great. You even used the right size tire under the fuel can.
Isn't it nice to know if you have to redo the oilpan gasket and intake gasket, you don't have to pull it back out of a car? Haven't wasted any antifreeze, etc.
Find someone to host the video. Remember, childbirth isn't pretty or easy to watch, but a lot of people film it.
I could kick myself for not taping mine (engine not childbirth). I must have run it a dozen times on the stand.
EDIT: you did remember to put a plug in that hose that goes to the P/B booster?

Egg83

Have you already figured out the valve train problem? It appears to me that your pushrods are a bit too short. The rocker arm should sit a bit higher on the stud. The fulcrum point should NOT rest on the "collar" of the stud. Eventually, the valvetrain movement will grind the bottom of the rocker right off in a matter of ten miles. I have seen this happen before on a Chevy 350 build.
You have to remember that the clearances as it sits on the stand are at room temperature. When that motor is working parts are gonna expand and clearances are gonna get tighter. You said that you were getting a pushrod length checker. If so what were your findings? -Bob

Sonix

iTrader: (1)

Yea, I used a vice grips to clamp the hose out of the back of the power brake booster.

Pushrod length checker - Yea, 7.85 - 7.90 would work good. No perf parts stores were open today. Custom lengths are pricey, but Ford 351C pushrods are 5/16" and 7.870" long = perfect. 3 piece ones like that should go fairly cheaply locally.

I ran it for a few minutes on the stand, and now i've partially disassembled it. The pushrods/rockers/studs look ok, with the 7.800" pushrods. I'll probably be able to have the right ones by the time I get back next friday.

F-BIRD'88

I like your engine test stand. You're very creative. It's simple and it works. Hope you don't mind if I copy it and make one for myself.
I think i might do the same thing with my Junkyard Dawg motor project.
It's been sitting on the stand in the garage all winter waiting for spring.
Fire it up and break it in so its ready with all the bugs sorted out before ripping the 400 out of the FireBird.
Have to see if I can dig up some old junk headers or exhaust manifolds for it.

Sonix

iTrader: (1)

Not at all.
Some specs:
You've probably noticed it's the "U" style stand vs the T style. The area where the engine bolts up, we cut off the 1" long tubes, and welded on 6" long sch 80 1/2" pipe. 130A or so with 7014 rod. Those are strong welds there. We welded the "legs" in place, so now it's fixed at that position. Oh well, I only intend on working on SBC's anyway.

Then just took some 1/4" plate transferred holes over from the motor mount "clamshells". Bolted those in place, took 1.5" square tube (.120" wall) and brought it down to the legs of the engine stand. Bolted more 1/4" plate onto the stand. Then welded the squre tube to that plate. Had to size the length of square tube based on the weight of a fully assembled engine. Still wasn't perfect, had to lean on the engine to get it to sag enough to fit in place.
Worked great though. Flywheel fits with those 6" extensions (3" would have worked)..
Leaks are inevitable I think. It's much easier to fix on a stand too. Now i'm just special ordering intake gaskets and a 1 piece oil pan seal.
Is there a "better" intake gasket vs the ones in stock at parts stores? They're a fel pro mcs one? I forget the p/n, but "fel pro 1205" was like speaking greek to them. Had no idea what I was talking about.

forgive the spelling/punctuation. Laptop keyboard is BRUTAL to use.

Sonix

iTrader: (1)

No one in town has .050" longer pushrods.
I special ordered 7.870" pushrods (ford cleaveland length, woohoo) from summit, rush airmailed ($70 shipping on $40 of parts, ouch). The parts will beat me home.

I'm going to check the intake manifold for leaks, and reassemble with a torque wrench on the intake manifold.
Here's hoping.

vipershark11

iTrader: (6)

some of my stud collars say lower than others because of their shape id assume like another person said about 1 wedging in which i had a problem with it cracking mine too. but i got fed up with them loosening while adjusting so i now have screw in studs that are pinned . those are never coming out. but my rocker sit a 1/4 or so above the collar i think a little less but none are even close. also if youre heads have pushrods guide slots on them beware of using 1.6 rockers i had to elongate my holes quite a bit so the pushrods wouldnt hit.

Sonix

iTrader: (1)

Yea, like I said above, mine did rub, so I drilled the rocker slot and used SA rockers.
But yea, I know what you're saying