PLANT PROTECTION

iTrader: (6)

I just slid my new LPE219(by Comp) into my 355 and put the 8,000mi Dynagear timing chain back on with 0 advance. I then degreed the cam, and my intake centerline cam out to 109, spec is 112. I then checked for IVO timing and found it to be 20 as opposed to the spec of 23. I threw those numbers into dyno2000 and it verified a LPE219 with 3d retard will have a IVO of 20. Where do you think I should look? I reused the timing chain from my old hotcam combo because it still felt like new, but that doesn't mean there wasn't a problem when it was new. Thanks for any input.

91Z28-350

What's an LPE219 (by Comp)? Who/what is Comp? The LPE219 (by Lingenfelter) has an ICL of 108 and an IVO of 1.5BTDC @ 0.050". I presume this 20* you mention is ATDC...what cam is this?

PLANT PROTECTION

iTrader: (6)

91Z28-350

That's wild....those specs aren't close to a real LPE219. At 0.020" lift, the LPE219 has a duration of 251 and opens at 17.7 BTDC. The exhaust valve events are quite different too. There's no overlap. That's really wild. This cam is going to make less power than the LPE219, I venture.

The LPE Cam Specifications.

Advance it 4* on install if you like. The cam was ground without a 4* advance, which the LPE219 does have. If you have an infinitely adjustable timing set, you can advance it 3*.

How did you get this? Is it a Comp Cams custom grind? If so, why an LPE219?

PLANT PROTECTION

iTrader: (6)

Actually, looking into it more, the cam is 3° ADVANCED, so my dyno2000 theroy is shot in the ***. I think I better start over and see what I come up with. I asked about the Comp LPE219 last year when I initally bought the cam on Corvetteforum and they said Comp is the new maker of the cam, so I accepted it. I did buy this used from a forum so why knows if it is legit or not.

Firebird90

iTrader: (1)

I had Erson make my 219 cam (Erson and Accel are sister companys)

I also have one from LPE/Accel with the card.

Sorry the pic is big...

91Z28-350

Sorry, PLANT PROTECTION. I wasn't paying attention, got caught up in how different the specs are. It is advanced. You can retard it if you like. It'll just move the powerband. But, it's really wild how the specs are different. I bought a 219 last year from LPE, but I didn't get a cam card. I bought their 74219LP special.

Firebird90, search the forum. Someone posted their 219 cam card and it's alot like the link I posted. It looks like the cam has changed over time. The valve timings changed. That's really strange. I wonder which is better.

PLANT PROTECTION

iTrader: (6)

From what I can tell, both cards give the same valve timing, just at different lifts. So basicly my question is, why did the cam not degree correctly?

AJ_92RS

Yes. Do it again. You're IC that you stated along with the IVO BTDC numbers you stated don't jive.

If the cam is 3* retarded, your IVO would move from 23* to 20* BTDC, which is what you said, but your IC would move from 112* ATDC to 115* ATDC if the cam was retarded 3*.

Are you sure you aren't getting the exhaust valve and intake valve confused? If your cam is retarded 3* then the exhaust centerline would move to 109* BTDC.

Just make sure you're reading from the driver's side of the block, and it's the SECOND lifter from the front, not the first.

91Z28-350

Manufacturing tolerances in the cam. Tolerances in the timing chain. It all adds up. Also, what AJ_92RS stated is dead on. I'm still blown away by the changes to the cam.

Another thing. When you degreed, did you turn the crank backwards if/when you overshot? If so, you're not supposed to do that. There's some slack in the chain and it throws off the reading. You're only supposed to go one way, forward.

That would be my guess as to why it's off by so much.

91Z28-350

Acceld Z's 219 cam card

It's different.

PLANT PROTECTION

iTrader: (6)

Ok, here is what I came up with, checked and double checked.
All figures at .020 tappet lift.
IVO - 15 BTDC
IVC - 53 ABDC
EVO - 59 BBDC
EVC - 9 ATDC
ICL - 109 ATDC
ECL - 115 BTDC
Intake duration - 248
Exhaust duration - 248
Intake/Exhaust lift - .351

EDIT: I just measured intake duration @ .050 and got about 219.5. I'm confused.

AJ_92RS

OK. I'm glad you did it again.

Based on those numbers (which actually jive with each other) your cam is 3* advanced.

If you don't want it advanced that far you'll have to change keyway grooves on your crankshaft sprocket if yours has them.

The only thing is most are in 4* incriments so if you change it you'll be 1* retarded.

And I don't know why you're confused about the 219.5* @ .050". That's what the cam card says the .050" duration is. .5* is nothing to worry about.

In case you didn't know (not to offend you) but duration @ .050" has nothing to do with the Intake Centerline. That number will only change by regrinding the cam.

Hope this helps.

PLANT PROTECTION

iTrader: (6)

Aj, I was confused because my numbers don't match the numbers on my cam card at all, I was thinking that I wasn't sold a LPE219 but then found duration was still correct. My numbers seem to match the specs 91z28 posted here .

91Z28-350

Are there any identifying marks on the cam? Give CC a call and see if there should be. I don't think the cam and the card match at all. It does appear to be an LPE219, so it's up to you to investigate the conspiracy theory if you want to.

AJ_92RS

There's no conspiracy. The bolt holes and locator pin were drilled 3* advanced OR someone didn't install the cam straight up like they think they did.

Seriously, I told you how to fix the problem. There's nothing wrong with the cam you have other than the IC being off a little. It's not going to make or break your engine.

91Z28-350

The valve events are different than on his cam card, as is the duration at 0.020". They don't match. You can advance or retard the cam, that won't change the duration @ 0.020" and the valve events are more than 3* off. Not to mention the overlap is different. These aren't things that can change with a simple advance or retard on installation. The valve events match the specs from LPE, which is different. The specs I posted are the current LPE219 specs, which is all fine and dandy. He has a current LPE219 according to the specs. The current LPE219 is ground 4* advanced. There's less overlap and it seems to be targeted more at lower RPMS than the "older" LPE219. I say older, because I don't know the history between the 2 cam specs listed in this thread. One cam card definitely looks aged, so I call it older, and I consider the specs on lingenfelter.com current.

I agree, no harm will come to the engine. I'd leave it as is, and not retard it.

I mention conspiracy because there are knockoff LPE219 cams that can be had. They are perfectly fine cams, just without the LPE name. It's also possible that the person that sold the cam gave him whatever cam card they could find.

Personally, I'd call CC to find out more about the cam. I've never heard of CC doing an LPE219 like cam, and the specs don't match. It's good to know, but it won't change the cam in hand since it was bought used.

AJ_92RS

What I'm saying has nothing to do with the cam you posted about. I'm trying to help PLANT PROTECTION figure out why his cam is 3* advanced when HIS cam card doesn't show it is. Other than that, everything else matches up.

Perhaps you misunderstood what I was saying based on that. I couldn't care less what cam YOU think he should have, or what the cam specs SHOULD be according to the name of the cam. All that matters at this point is that he degreed HIS cam and and the numbers didn't match the cam card HE has.

Up until now I really wasn't even paying attention to anything you wrote because all you keep doing is dwelling on the fact that his cam isn't an "original" LPE cam.

91Z28-350

Are you on the same thread? Read what PLANT PROTECTION stated.

No. That's what I and PLANT PROTECTION are saying. Nothing matches HIS CAM CARD. I don't know what card you are looking at, but absolutely NOTHING matches except for the duration at 0.050".

No, I didn't misunderstand a thing. You aren't answering his questions, but answering what you think should be the question. I've stated that I don't care what cam he has. All I know is that it DOESN'T MATCH HIS CAM CARD.

Would you care to explain how retarding the cam will resolve his issue? You don't just retard a cam based on an ICL that you think should be right. You should degree and install the cam according to the cam card. The IMPLICATION is that the cam card MATCHES the cam. I'll state this in plain english...HIS CAM CARD DOESN'T MATCH HIS CAM. HE SHOULD NOT ADVANCE OR RETARD ANYTHING BASED UPON SOME ASSUMPTION OF ICL.

I'm "dwelling on it" because the cam he has matches the specs on the LPE webpage. His cam specs DO NOT MATCH HIS CAM CARD.

We're saying similar things and you are being DENSE about it. I've implied on multiple occassions for him to determine the specs of his cam, which he has. To degree a cam, you have to know what you have beforehand. If that's in question, determine it.

1) Would you care to explain how retarding the cam on install would read a duration of 270/270 (based on his cam card) when he degreed it as 248/248?
2) Would you care to explain how retarding the cam on install would make his valve events match his cam card?
3) Would you care to explain how retarding the cam on install would change his overlap?

You don't advance or retard a cam on install because YOU think his cam should have an ICL of 112 or because YOU think HIS cam card is correct for his cam. If I am wrong, PROVE me wrong. Answer the 3 questions.

I don't care what name he has on his cam. I care what his specs ACTUALLY ARE. Do you understand?

I'm quoting his measured events. I suggest you go read HIS cam card.

EDIT: PLANT PROTECTION. Sorry that all this had to pollute your thread. I'm sure you've buttoned up by now, but if you haven't, just leave it straight up. If you want, you can measure your events at 0.050" and get a better idea of which cam card you should rely on. It shouldn't match the other picture in the thread. If it does, however, then something screwy is going on so measure again. They say 3 times' a charm.

It's important for you to identify the cam specs that you have. Ignore the the cam cards for the time being and spec it out as best as you can, then go and try to find the cam card that matches...for your reference, to keep handy. If anything is in question, leave it straight up. Do not advance or retard anything. Do not go off of assumptions. Rely on the manufacturer to have indicated dot to dot is where it should be installed (as if you didn't have a cam card).

AJ_92RS

Easy. I usually always ignore advertised duration numbers. Since one cam company uses .020", one .006", another uses..... get what I'm saying?

Also, I'd suspect he's using a hyd lifter to check the duration figures and didn't use a solid lifter. Am I right, Plant Protection?

How would I guess this? Based on the fact that with the two durations the cam intensity is 29. That's beyond radical. About the only cam with that steep of a ramp angle I've seen is a solid roller.

E.G., the Xtreme series cams that are ever so popular, and specifically the XE268 that is so infamous with CHP magazine has a hyd intensity of 44. My Magnum 280 I have in my '71 has an intensity of 50.

But only experience would tell you to look at something like that. Other than that one thing being wrong, everything else matches up. The duration @ .050" does, the LSA does, the IVO,EVC,IVC, & EVO points do match IF the cam was to truely be installed "straight up".

BTW, that's the experience of doing wrong myself that I'm speaking of.

91Z28-350

I do understand perfectly well. I generally ignore ADV durations unless I know where it was measured. I then use the ADV with the measured value at 0.050 or 0.020 to determine the intensity of the lobe as long as the comparison is consistent. Comp Cams advertises duration at 0.006, so does LPE, so using the 0.006 value for comparison wouldn't be bad. The 219 for LPE is at 0.050.

BTW, if you look at the lingenfelter link, it has a good profile of all their cams. These are measured values of actual cam samples. I suspect LPE would measure them correctly.

That would be bad, yes.

I don't think it's that radical. You need to look at the lifts of where you are taking as the 2 sample points. The LPE219 has a duration of 280/280 @ 0.006". The intensity is a bit more than 29, it's 61. If you're using the 0.020" and the 0.050" for the intensity then are you using that for your XE268 calculation? I'd venture that you aren't and you are using the 0.006" value and the 0.050" value. CC advertises at 0.006" and is spec'd that way. When you compare the intensities, the 2 points need to be consistent otherwise the comparison is flawed.

http://www.compcams.com/Technical/Se...umber=12-268-4

I don't get this part. How do the valve events match if installed straight up? I've plotted it on a 2D chart and tried to advance it 3*, and they don't match up with the cam card that PLANT PROTECTION or Firebird90 posted. Perhaps I did it wrong, but I don't see it. Also, the overlap changed. When you advance or retard on install the basic cam stats, like overlap, don't change, they shift. Please elaborate on how they would match? I'd like to understand how this was derived, if I'm wrong, I'd like to be corrected and understand the proper way.

PLANT PROTECTION

iTrader: (6)

You are, however, the engine has no heads so I figured there would be no plunger movement with only dial indicator resistance. Correct me if I am wrong. Of course, now factor in geometric error. How are you guys calculating cam intensity?

91Z28-350

Take 2 tappet lift points and subtract the duration. You do that for the intake and exhaust lobes separately. All it's doing is, the lower the number, the more aggressive the ramp rate. It's not a full picture, but a decent guesstimate based on limited specs.

Hydraulic intensity is duration@0.006-duration@0.050.
Major intensity is duration@0.020-duration@0.050.
Minor intensity is duration@0.010-duration@0.050.

For the numbers to mean something the tappet lifts need to be at a consistent spot. If you're comparing duration@0.020-duration@0.050, then it's smaller than duration@0.006-duration@0.050. In essence, you can't compare hydraulic intensity to major intensity and expect it to mean something.

I presume AJ was using, for the LPE219 value, duration@0.020-duration@0.050 (your measured 248-219==29) and comparing that to the XE268 duration@0.006-duration@0.050 (268-224==44). The numbers work out to 29 and 44 respectively, but they are meaningless because the numbers were done at 2 different tappet lift points and comparing major intensity to hydraulic intensity.

The value for the LPE219 is actually 61 when using hydraulic intensity (280-219), according to the LPE webpage. I don't know what the duration specs are for the Comp Cam grind (using your cam card) other than the 0.020 and 0.050 durations, but I don't know the 0.020 durations for the other cams AJ mentioned so no direct comparison can be made. A comparison can be made between the 2 LPE219 specs using duration@0.020-duration@0.050. The comp cams one is 270-219, the LPE spec one is 250-219. The LPE one has a more aggressive ramp....in that small tappet lift section.

You really need more data points for an accurate comparison.

AJ_92RS

No no. I came up with 29 as the hyd. intensity based on the 248* duration that Plant Protection got (I'll use "PP" for short ) compared to the .050" duration figures of ~219* that he also got. It had nothing to do with the 270* that CC uses.

And you know what, there is no way in Hades the cam, based on what PP measured, can exist.

.527" lift at the valve (.351" at the lobe) with only 248* advertised duration? No way.

And I have a feeling that the closing events he posted are based on the .050" specs, not .020" advertised.

Something just isn't adding up here and I think that's what's causing all the confusion.

Perhaps you're right and I overlooked a few things while trying to help what he posted at the time and not comparing what he previously posted.

I mean, based on his Intake Center, Exhaust Center, the IVO,IVC,EVO and EVC events compared to the lift of that cam... something has me, as well as possibly you, confused.

Do me a favor and play with your 2D chart and compare the valve events (IVO, IVC, Etc.) when using .006" compared to .020". I think that PP is using DD2000 to calculate his advertised duration. That's what I just did for kicks and grins and came up with the same boggled numbers he did. The problem with that is DD2000 uses .006" when you enter the specs as "Advertised Duration" figures. You can't use it to check advertised specs @ .020"

I could sit down with a pencil and calculator and figure it up, but I just got done arguing with a used car salesman about a car that evidently has gold bars under the seats somewhere. I'm tired now.

91Z28-350

Yeah, I figured that, and mentioned it.

Why not?

http://www.lingenfelter.com/instructions_cam.htm

scroll down to the bottom, it's a cam LPE measured (not advertised numbers, but measured). This is the late model LPE219 that I referred to. The CC one PP has, I have no clue about.

The advertised duration is 280/280, not 248. PP measured 248 at 0.020", not 0.006" so you can't make a direct comparison to other numbers floatin around out there which normally use 0.006" or 0.004" if you are Crane Cams.

I don't know. PP said it was 0.020" and they match almost exactly to what's on the LPE webpage.



Exactly. At this point, I'd say button it up, dot to dot + 1 rev. If not, pull the cam and have it measured if you're REALLY interested about it.

I'll get to it tonight, and I'm using the pencil and paper method.

Yuck, any normal person would.

AJ_92RS

You know what. I just realized that I did compare the .020" specs with the .050" specs to get hyd. intensity. That’s the wrong way to compare.

I just did a friend’s XE274 for him because his cam card said he had 274*/286* but had the lifts both at .490" instead of .487"/.490" as advertised. I guess I still have .006" in my head.

Other than that, his cam (my friend's) matched his card exactly.

I think there are too many cam cards on this page and I got corn-fused and looked at the wrong one???

PLANT PROTECTION

iTrader: (6)

Now that we're all on the same page...

The front of the motor is buttoned up so it is staying as is. I do have a few lingering questions though, I want to walk away from this either knowing that I did or did not degree this cam correctly. Was it ok to use a hydraulic roller lifter instead of a solid while degreeing a headless engine? Does my cam exist, ie, is it possible to get the .020 numbers I pulled or was I in error somewhere? Also, it's good to see that this thread stayed civil, it could have turned out much worse. Thank you both for your insight.

Mkos1980

iTrader: (8)

I think there is something wrong with my 219 cam. I installed it dot to dot and i am getting MASSIVE valve chatter at 3000+ RPM.s I accually have to run the base timing at a -5* in order to stop the chatter. I'm going to be degreeing the cam soon to see whats up. I've taken a ton of timing away in the chip with no results and also added fuel with no results. Its so loud I cant even hear the motor.