Fresh engine, wiped cam? Tick? (new pics added)

[myasylum]

O.k. Stupid question. I just went out to my car and realized that I can only have one lobe "base circle of the cam". When one is down the other is one the way up. Is that fine?

Also... The rust (or whatever it is) looks worse because it's a close up picture. Just from looking at it with you eye, it doesn't look that bad. If you run your finger across it it feels smooth all the way across.

Could this simply be possibly because of a bad break in?

 

[mopar340dave]

its just flash rust,,,it's a whopping .0001" deep, not a problem as long as it stays soaked in oil...but the lobes appear to be shot.

I agree that you don't have to rebuild the engine.

 

[mopar340dave]

you can get both lobes for a cylinder on the base circle at the same time. just rotate the engine slowly until both lifters are bottomed out.

This should help you understand what you are dealing with:
http://image.chevyhiperformance.com/f/18049893+w750+st0/0905chp_04_z+lobe_separation_angle+chart.jpg

 

[myasylum]

Which am i measuring? The lifters? or the shaft to the shaft pedestal?

I can get the push rods tight just buy turning the screws on the shaft! their isn't much left to tighten either. (or so it appears)

I'm sorry? I'm feeling really dumb here!

Also, I checked for a price on my cam, and the price went up $35.00!! Just on that one cam though (of course!). I wonder if I should go one bigger then?

 

[mopar340dave]

at this point, back your bolts out until the pushrods will rattle a little when you wiggle them...in other words, not seated snugly...then 1/4 turn of the bolts at a time, check for the pushrods to "seat" in the lifter and rocker.
at this point, measure the gap between the rocker shaft and the pedestal.
It should be very little...less than .050" for sure.

.050" is 1/2 of 1/10 of an inch

 

[Cudafever]

I'm sorry guys but i don't see anything wrong with the running surfice of then lobes......can't see the vary back one but they look good to me!

How about a close up of the running face of the lifters....so we can see a good ware pattern of then.

Am i missing some thing here!....... don't see damage to cam

I have seen coating put on cams that look like the rust, every say it its.

 

[inkjunkie]

problems probably stem from the very start.....perhaps this should have been mentioned????
http://www.forabodiesonly.com/mopar/showthread.php?t=87827

 

[mopar340dave]

If you have a spiral bound notebook or the package backing from rtv thats made of thin cardboard they all seem to be .027"-.030" thick. you can cut 4, 1" squares in them, punch or cut a 3/8" hole in them and then install two under the shaft at each hold down point...you will then have accomplished a poormans check of your pushrod length.

If they are now snug, your pushrods are a little too long and you need to shim the shafts up to compensate or replace the pushrods with the correct length...shims are cheap but the new pushrods are the right way to fix it. Shimming the rockers up will slightly change the geometry at the valve tip...in your app this is probably not an issue. This is far more important in a high lift app.

If they are still a little bit loose, remove one piece of cardboard from each bolt and resnug them. If the pushrods are now snug, your pushrods are the correct length.

 

[myasylum]

What are you using to measure the gap? will a feeler gauge fit in there? EDIT-sorry Mopar340Dave... you answered my question ask I was posting this

Inkjunkie- that is why I mentioned if improper break in might cause this.

and now Cudafever sees nothing wrong with the cam? oh boy? I think I'll start fresh again tomorrow.

Thanks a lot guys! You rule!

 

[myasylum]

O.k. I have this cam now... (that they increased the price on)

Brand Lunati
Manufacturer's Part Number 60403LK
Part Type Camshaft and Lifter Kits
Product Line Lunati Voodoo Cam and Lifter Kits
Summit Racing Part Number LUN-60403LK

Cam Style Hydraulic flat tappet
Basic Operating RPM Range 1,800-6,200
Intake Duration at 050 inch Lift 226
Exhaust Duration at 050 inch Lift 234
Duration at 050 inch Lift 226 int./234 exh.
Advertised Intake Duration 268
Advertised Exhaust Duration 276
Advertised Duration 268 int./276 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.494 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.513 in.
Valve Lift with Factory Rocker Arm Ratio 0.494 int./0.513 exh. lift

Could I get one step higher for a cheaper price? This is a stroker motor too.

Brand Lunati
Manufacturer's Part Number 60404LK
Part Type Camshaft and Lifter Kits
Product Line Lunati Voodoo Cam and Lifter Kits
Summit Racing Part Number LUN-60404LK

Cam Style Hydraulic flat tappet
Basic Operating RPM Range 2,200-6,400
Intake Duration at 050 inch Lift 234
Exhaust Duration at 050 inch Lift 242
Duration at 050 inch Lift 234 int./242 exh.
Advertised Intake Duration 276
Advertised Exhaust Duration 284
Advertised Duration 276 int./284 exh.
Intake Valve Lift with Factory Rocker Arm Ratio 0.513 in.
Exhaust Valve Lift with Factory Rocker Arm Ratio 0.533 in.
Valve Lift with Factory Rocker Arm Ratio 0.513 int./0.533 exh. lift

 

[mopar340dave]

you should not see a wear pattern that goes wide at max lift. That is where the taper of the cam is most obvious.

If you could measure a brand new or any good used flat tappet cam you would find that the fwd edge is taller than the aft

~rotates lifter/pushrod to prevent excessive wear
~makes cam thrust fwd

yes, improper break-in can cause this.

the pushrod length check is not hard, but if you don't have the tools you have to get creative.
do you have a dial caliper?


~edit~update~
The above in italics is not completely right, acording to David Vizard.
It appears that the lifter to lobe interface will vary from lifter to lifter. I'm gonna have to take a close look at this, but I'm thinkin that the offset and taper counter each other and the oil pump/disributor drive gear are what give the cam its fwd thrust.

 

[mopar340dave]

your factory rocker arms are always less than spec and never identical, it seems, so your actual lift at the valve will be lower than the cam spec says...but just a little.

when you turn the engine over with the rockers bolted on, look at your springs at max lift....you need to be sure your springs are not binding or that the reatainer isnt hitting the valve seal/guide. If they (the valve guides) were not milled down a little from stock height, they also may be your problem.

 

[Cudafever]

If we were taking about a roller cam then that patter would be weird....But it a flat tappet(Hyd) and that ware pattern, on the cam lobe is how the lifter is able to rotate.

Would really like to get a close up pic's of the face(were the cam lobes rubs on it) of all the lifters..................

 

[myasylum]

I have pics of the lifters on Page 2. I can post more, but I think I'm tried for the night.
I can post more tomorrow. I really do appreciate you help!

 

[mopar340dave]

spring bind pics along with 1000 words...give or take a couple hundred...

http://cranecams.com/?id=5&show=faq

cudafever, check pg 2 post 23

some of the circles are where they belong, some are not and it looks to me to be an eratic and too wide pattern on the cam

http://www.forabodiesonly.com/mopar/showthread.php?t=94693&page=2

 

[Cudafever]

Ya i saw then, but we need to see the pattern or should i say ware patterns of the lifters.....some of then you can't see

didn't you say this was a stroker eng? If so, and you do decide to replace the cam......I would step up to the 60404 cam!

 

[myasylum]

Yes, it is a stroker engine... but another thing I worry about is that it has a Eagle cast crank. I have heard they suck, so I kind of fear pushing to much.
Also like I say... Would the stock rockers be o..k with the 60404. I just thought maybe that would be to much lift?
Oh also with that cam they recommend dual springs! They do on the one I have now as well. I just found a single spring with a comparable spring pressure to the dual spring they recommend.

I'll post closer pictures of the lifter tomorrow.

mopar340dave- I'll be reading that for sure! Thanks!

 

[Cudafever]

spring bind pics along with 1000 words...give or take a couple hundred...

http://cranecams.com/?id=5&show=faq

cudafever, check pg 2 post 23

some of the circles are where they belong, some are not and it looks to me to be an eratic and too wide pattern on the cam

http://www.forabodiesonly.com/mopar/showthread.php?t=94693&page=2

I agree, but i don't thing that it is at to the point of failure it look like the crown of the lifters is intact, but can't tell for sure.

I just don't thing this is were the noise is coming from...........I do suspect, as u do that the lifter preload is, at least, some of the problem

Yes, it is a stroker engine... but another thing I worry about is that it has a Eagle cast crank. I have heard they suck, so I kind of fear pushing to much.
Also like I say... Would the stock rockers be o..k with the 60404. I just thought maybe that would be to much lift?

I thing the biggest question is retainer to guide clearance in other words it may have to much lift.........something to worry about after we find the cause.....

 

[mopar340dave]

I think its a 318, no?

 

[mopar340dave]

yeah, I agree, thats why I suggested just havin the cam reground/polished out by lunati or a capable shop and just replacing the lifters.

The mopar valvetrain mos def appears simpler than it is. Once ya build a couple and have to work little issues out, ya start seeing what to look for.
The stock style set-up, with all the right pieces, including some roller rockers, can really rip some serious rpm and hp....above about 7500 rpm gets expensive though.
The stock rocker gear is perfect for your setup.

I wish I had the web when I was 19! LOL

 

[myasylum]

360

The lifters are flat. A lot of it is lighting, and the camera set at Macro. It seems to pick up a lot more. You cant really notice the swirls without looking for them.

Would having the cam ground be cheaper then a new one? I'm sot sure if I can find a place to do that around here??

 

[Cudafever]

360

The lifters are flat. A lot of it is lighting, and the camera set at Macro. It seems to pick up a lot more. You cant really notice the swirls without looking for them.

Would having the cam ground be cheaper then a new one? I'm sot sure if I can find a place to do that around here??

If you put a straight edge across then you will find that they are NOT flat and are not sapost to be they have a slight crown.....when the crown goes......the cam fails!

 

[mopar340dave]

I think I would send it back to lunati, after talking to them, of course.

They may hook you up. It's part of a huge Corp. now.
Tell them your sad story, they might do it for shipping!
Ask them if these are the best lifters for your app or if they reccomend another and tell them you'll buy another set. Ya might get lucky. Be real nice and tell them clearly without gettin off subject. You could write it down like you are going to a meeting, because you are.
They like word of mouth so hooking you up is like cheap advertising....tell them you talked to us all about it. It's worth a shot.

and send them your pics, too

 

[mopar340dave]

cudafever is right about the lifter face.

it is not perfectly flat...the very center is protruding slightly...

this is way better than I could explain it...this guys been to more than just the school of hard knocks!!! If you don't know who he is, you should. Click here and you will:
http://www.enginebuildermag.com/Article/1232/vizards_view_avoiding_flat_tappet_cam_and_lifter_failure.aspx

Taper and Crown
In reality, there is no such thing as a flat tappet cam and lifter. The lifter has a crown on it, typically between .050? and .100? radius. This runs on a cam profile, which is tapered across its form. The cam profile itself does not run centered on the lifter but is offset to one side. The combination of this offset and the cams taper and the lifter crowning causes the lifter to rotate. At the end of the day it is the lifter rotation (which considerably reduces the rubbing speed) that saves the situation from a sure disaster.
To make sure that the system works as it should first measure each lobe on the cam you intend to install and check that it has at least one thousandth taper across the lobe (1.5 to 2.5 are typical). For a Chevy the largest dimension should be toward the back of the cam. On any others the largest dimension should be on the side of the profile that runs toward the outside of the lifter diameter.Next check the lifters. It's unlikely you'll find one wrong, because quality control on these items is very high. But you can make a quick check by just putting the face of two lifters together and holding the pair up to the light. This will quickly establish that the crown exists.
The type of lifter you choose can also be instrumental in extending the life of the valve train. More expensive hard face lifters as supplied by most cam companies are well worth it, especially if you're building a big block Chevy, which is more prone to lobe and lifter failure. And be aware that many cam companies offer a cam hardening service, which is also well worthwhile.
The lifters you have do still have a crown, it appears, but the visible wear circles are all different. That does not mean they are bad. The pic does not show them well enough, but the wear circles do appear to be minor.
The article (David Vizard) suggests that a minimum of .001" taper is required for a used cam....

 

[Cudafever]

Thanks for the link, all way enjoyed any thing from David Vizards.