pmotts

Mark,
Good luck finding your problem.

Ken,
Your tool has worked perfectly for 3 of my GT's and two of those were confirmed using the WSM method. I guess me and dozens more were just lucky and Mark K's is right...

Cheers,
Jim

PorKen

These two statements are contradictory.

You don't know if the block/gasket/head combo you have has the same measurements between the crank and cam centers. Using the WSM method, if the centers are farther apart that stock, it will advance the timing, closer will retard. What you do have is stock cams in a stock head, which the 32V'r measures, irrespective of crank/cam center distance.

My S³ with ignition tuning and X-pipe can make 316 rwhp on the dyno, but it has smaller valves, smaller ports, no headers, stock size exhaust tubing, and no e·RAM(s).

You have accurately created a reading using the WSM technique which is flawed. You do not know if the crank/cam centers are stock. You measured the plunge reading with an engine that had had no oil pressure to pump up the cam chain tensioners. The chain may have been tight because the cams had rotated apart from valve spring tension.

People keep telling you they have verified the plunge readings with the 32V'r, but you don't seem to hear them.

The only independent way for you to be sure is to use a degree wheel and dial indicator to find the lobe center, then set the timing to the degree spec, as was done with Dennis' engine. And/or you can use the 32V'r, which is a degreed indicator of stock cam timing.

(Bill's video of Dennis' engine rebuild)

mark kibort

Jim, I dont have any issues. Ive timed the car out at where the WSM says they should be timed. Im sure there could be differences in what im seeing vs what everyone that Ken has worked with have seen. Could be due to the mismatched parts, I dont know. The point is, Ken has made a buncy of assumptions and statistically insignificant tests. Sure, I would bet the next stock S4 that he tests (or someone tests using the 32R), would show a good correlation of the lifter depression method vs the tool. The point here, is how many cars has he tested? How many variations of advance vs retard on the cams relative to the intake or exhaust has he done? a total of 5 -10 cars?
How many 928s were made?? why do I see such a difference?

The point now is that he has now told me that the exhaust is more important than intake. (verified by that little blirb a post or two ago) Now, the list is full of contraditions, and very few know my real objectives here.

The objectives are to have a dependable engine that doesnt brake the transmission. my goal based on those that have broken, is near 400rhp. Many have urged me to get bigger valves, CF intake, etc. I dont need the extra power for my racing (now anyway.) If i do, i can bolt it on later and return the stock Holbert heads to the original short block.

If the way I have timed the cams is more advanced than I have intended, which is near equal to how the holbert cams were orginially set, big deal! I prefer to have a lot more torque down low, as that will increase my average HP used in racing, mainly based on my desire to short shift a bit with this new motor. currently, im at 260rwhp at 4500rpm to 305rwhp at 6200 to 6600rpm.
Kind of an average of near 280rwhp. I can get a MUCH better average by an engine the expected increase of torque in the mid range. Either way its just not that big of a deal. based on my compresson numbers, how the car feels, and soon to be seen, dyno runs, I will know the answers to how sucessful this new engine and its set up will be. until then, its ALL speculation with some data point indicators.

mk

mark kibort

ken, i would venture to say that the tensioner has little to nothing to do with the cam timing. Rember, the tensioner is on the "Non-pulling/tension" side of the chain. meaning the diistance will never change on the cam sprockets, but the slack side could rattle. Kind of like gear changing mechanism of a bicycle. if you lost the derailer, the distance of the top of the sprocket on the pedals will be directly tied to the rear wheel and will not change. similarly with our tensioners. the are designed to keep "Tension". take the tensioner out, you might skip teeth and have vibration, but if its under load, the distance is fixed by the chain link profile and sizes. if the valve springs were holding tension on the "tension" side, then it would be pressing the sprocket teeth to the rear part of each chain link and that wasnt the case. the chain only got lose on top if i rotated the crank backward a degree or two.

anyway, the way i have it set up, the intakes are correct. If what you are saying is true, then my exhausts are off by 6 and 3 degrees to the advance. thats pretty substantial. I have an idea to check this via total valve closing indication with compressed air. I did this already, but the lifters had not been pumped up with oil and the results were inconsistant on the exhaust, but not the intake. It could have proved you are right, but the duration number was way off too, so the test wasnt valid. If i can get the same duration value as well as close or open position, this might be a good indication of what i have.
If we had solid lifters, this would be a piece of cake test!


mk

atb

What was the thickness of the cometic gaskets used?

IcemanG17

Mark
I'm sure you can find the missing 50hp between yourself, this list and Doc Brown.....

My 1st thought was some type of fault related to knock sensors, hall sensor or something else that causes the EZK to default and retard timing, which also makes sense with the "gain" of torque you got on the bottom?

Knowing you run stock brains...why not try a new set of brains with the custom shark tuned chips? I'm also guessing that the spanner didn't show any faults? Or just take the brains out of Joes and try that?

mark kibort

That idea kind of confuses me. I thought the retarding of ignition timing gives you more hp at the high rpms? Bill was mentioning that the WOT switch causes about 9 degrees retard, and then the knock sensor can cause another 9 degrees. (18 degrees retard potential if you have a knock?)

Im also confused as his car with little changes, has gone from 475rhp to 505rhp back down to 475rhp.

mk

PorKen

These statements contradict each other.

When the chain is untensioned, as you rotate the engine with the crank bolt, the exhaust cam retards the intake cam until all the slack in the chain is taken up. In order to achieve the WSM plunge reading on the intake cam, the exhaust cam has to be advanced versus the crank.

The amount of crank retard to loosen the chain shows in part how much advance error you can expect with your readings.

If you measure with the dial indicator now that the tensioners have oil in them, you will find your readings have changed.

Correct. Enough to lower the TQ and HP peaks by ~600 rpm, and raise the dynamic compression so you will have more chance of knock retard.

Dennis Wilson

MK wrote

"I prefer to have a lot more torque down low, as that will increase my average HP used in racing, mainly based on my desire to short shift a bit with this new motor. currently, im at 260rwhp at 4500rpm to 305rwhp at 6200 to 6600rpm.
Kind of an average of near 280rwhp. I can get a MUCH better average by an engine the expected increase of torque in the mid range. Either way its just not that big of a deal. based on my compresson numbers, how the car feels, and soon to be seen, dyno runs, I will know the answers to how sucessful this new engine and its set up will be. until then, its ALL speculation with some data point indicators."

Mark,

I seem to remember a thread where you wrote a book trying to convince me this wasn't correct. Change of heart or did you read the article?

Watch that valve lash.

Dennis

LT Texan

what were the readings? (did I miss that?)

AO

Another data point here,

When I had my GT motor out last winter, I timed the cams per the WSM and double checked with PorKen's tool. The tool appeared to be very accurate.

mark kibort

ken, No there is no contradiction. Think about what you are saying. the cams are tied together with a chain, but the tensioner part is on the opposite side of driven side of the sprockets. meaning it DOESNT MATTER if there is slack in the chain on that side, ONLY on the side that is being driven the chain comes to rest on a flat pad that doesnt move. its straight accross to the othe sprocket. If you think about it, you will see that this doesnt effect cam timing. there is no slack on the chain on the driven side. the slack is on the tensioner side, OPPOSITE to the driven side. notice how the tensioners are upside down on one side????
Thats Why!!!

I did another test today that might interest you:

Cold compression this morning, 190psi driver side. 190psi passenger side. Hmmmmm equal. i did it again. same results.

Then, i went on my speed run to get some 60-100 times with the new engine.
AFRs were good based on the narrow band. When I got back from the run, the engine was real hot. 180oil, normal water. compression: 210psi, on the driver side and exactly 210psi on the passenger side!! dead nuts equal, just like the 2mm setting per side for 20 degrees advance of the crank past TDC.



mk

mark kibort

Its correct for trying to maximize HP when you dont want to run higher rpms. The only reason i dont want to run high rpms, (and I could write you another book in case you didnt understand the first time) , is that this engine is somewhat new and unproven. keeping the rpms down will limit some of the risks, with a trade off for others ( more torque exposure to the transmission and driveline)

Again, I will have a ton more hp with this engine from low to high rpms. With the higher torque at the lower rpms, that just means I can save some HP losses by short shifting. It still would be faster, no matter what the torque to shift at redline unless the torque falls at a greater rate than the RPMs are going up. (ie plunging torque) Otherwise, if you read the book again, and understand my goals with this engine, it will all make sense.

mk

PS, watch valve lash?? do we have lash in our hydralic lifters? what am i watching for?

mk

PorKen

You remeasured after running the engine? Or are you still referring to your previous incorrect readings?

mark kibort

How can you call my readings incorrect. They were measured several times, several different ways with the same results. (including the traditional method).
You already agreed this discussion and debate was about one method vs the other. Ive also mentioned that the tool is certainly likely to be able to determine exhaust cam aligment. If that is more important than Intake, based on lifter depression for a given crank movemement, then im listening.

However, I think my cold vs hot equal compression says it all. unless you are going to criticize the way i measured compression. taking pressure , unitl it doesnt rise anymore. about 12 revolutions, or 6 compression hits.

Did you think about how the chain is oriented with the spring, oil actuated tensioner side, on the "slack" side of the chain. Think about it again. If i added 100feet of change after the chain passed over the driven exhuast cam, it wouldnt change the timing. the tight side of the chain determines the position of the inake cam. This is ONLY based on chain link spacing. If I'm missing something here, let me know

mk

mk



Ken, the tensinoer cannot change the cam timing, nor can the oil in the tesioner.