H/C/I Advice

[SkurdalenFox]

Originally Posted by coupe

Well, that many degrees seems way off to me when they certainly must expect 90% of people to install it "dot-to-dot." That's why I wondered if your dial-indicator was giving you a true .050"

Please go over it one more time. Sorry. Also compare intake to exhaust, to see if the LSA and centerlines are as stated.

I measured again, from a blank slate; relocated TDC and all that, and everything checks out as stated in the cam card. Intake and exhaust opening and closing, max lift, and duration. My book says that I can't use the lobe centerline method as described in the book to check my cam as it has asymmetrical lobes.

Since all the timing events check out, and have been measured at least ten times, is it safe to judge that the cam is degreed properly?

As to the inaccuracy of the dot-to-dot method, six seems like a lot to me as well...but I guess it's typical.

Originally Posted by Michael Yount on another board

But if it's an aftermarket cam or you're serious about being certain the cam timing is accurate with the stock cam, you should use an indexed timing set -- and then use a dial indicator and a degree wheel to set the cam timing exactly where the cam card calls for it to be. Any other approach is just guessing. And even with brand new components, it's not uncommon that a 'dot to dot' aftermarket install will result in cam timing that's as much as 4-6 degrees off of what's called for on the cam card.

Bottom line is -- as long as you're willing to guess at the cam timing - then a dot to dot install is just fine.

http://www.corral.net/forums/showpos...25&postcount=3

[coupe]

Hmm. I knew it was pretty normal for the Ford cams, but the crane? I bet alot of it has to do with the timing sets. Their "dot" might be slightly off, which propogates the error significantly by the time you put a degree wheel on.

I think you're safe with what you've done. Keep us up to date on the build and thanks for sharing the "cam-degreeing" info. Great technical thread.

[QWKSNKE]

Originally Posted by SkurdalenFox

Did I just pay $50 for 3 horsepower at 5900RPM? [/Rhetorical]

probably. I don't see it helping out significantly but as you stated you enjoying learning something new and that makes it worth it.

In my opinion this where the custom grind cams are a safe bet on the dot to dot install.

[SkurdalenFox]

As I said, the closest I could have gotten the cam without the adjustable timing set would have been about three degrees retard. Three degrees assumes a similar error rate with the hypothetical non-adjustable set.

I've been looking all over, and the data for my particular engine are not available. Nevertheless, here is something similar.

Six degrees advanced
RPM Pwr Trq
2000 135 354 14.67 77.2 228.2 16.7 179.3
2500 174 365 14.64 79.8 225.1 17.8 185.0
3000 215 377 14.61 82.3 228.1 19.0 191.0
3500 259 388 14.57 85.8 230.9 20.3 196.8
4000 299 393 14.51 88.1 232.8 21.7 199.1
4500 338 394 14.45 89.5 234.8 23.1 199.7
5000 365 384 14.38 89.3 230.8 24.7 194.4
5500 379 362 14.31 87.7 220.7 26.3 183.4
6000 376 329 14.26 83.9 204.5 28.0 166.5

Six degrees retarded

RPM pwr Trq
2000 128 335 14.67 69.4 216.8 16.7 169.6
2500 163 342 14.65 72.0 212.0 17.8 173.4
3000 199 348 14.63 73.4 212.1 19.0 176.4
3500 242 363 14.59 77.3 216.9 20.3 183.7
4000 285 374 14.55 80.8 222.7 21.7 189.6
4500 327 382 14.49 83.5 228.3 23.1 193.6
5000 362 380 14.42 84.9 228.8 24.7 192.6
5500 388 370 14.35 85.4 225.0 26.3 187.5
6000 401 351 14.28 84.3 216.4 28.0 177.7

I have no idea if the effect is linear, but it seems to me that even three degrees retard would have a substantiative effect.

[SkurdalenFox]

To make a solid lifter, I disassembled the lifter to be used in that bore,


Put the plunger in backwards,


And put it back together


I measured the length to the bottom of the cup where the pushrod sits, and the solid and stock lifters are within a few ten-thousandths of one another.

I marked the top of the valve stem with a sharpie.

I put the solid lifter in the bore and setup my adjustable pushrod, and then I tightened the rocker bolt to the point that I could just feel tension on the pushrod. I then used a torque wrench and tightened it to just a hair under 20ft lbs. It took about a half a turn to two thirds of a turn to get the wrench just shy of 20ft lbs.

I then turned the engine over 720 degrees. I removed the rocker arm and took a gander at the mark. I measured the rocker tip sweep at .0335” wide and perfectly centered.



I experimented with the length several times, but that’s about the narrowest and centered-est I could ever achieve. How does that seem? It can’t get any more centered, but maybe I can get a narrower sweep? What do you guys think?


What’s sort of funny is that the best pattern I got was achieved with this length of push-rod! It may be hard to tell from the picture, but it's exactly stock length.


I also checked the exhaust valve on the number one cylinder. It gave identical results as the intake. Should I bother with the other valves?

[coupe]

Naa. You're good. But why the "homemade" solid lifter? That cam was meant for a Hydraulic. Are you going to experiment with a lash value?

Keep in mind, you will lose a little torque with the solid lifter compared to the hydraulic. Why not leave it hydraulic?

[Italian LX]

Originally Posted by coupe

Naa. You're good. But why the "homemade" solid lifter? That cam was meant for a Hydraulic. Are you going to experiment with a lash value?

I thought he was just doing that temporarily while he was measuring for the pushrod length.

[SkurdalenFox]

Yeah, Italian is correct. Sorry Coupe, nothing so interesting.

Now I have a question about measuring P/V clearance. I have completed one measurement using the clay method and the above solid lifter. The problem is, my P/V clearance is off by an order of magnitude. There is only .015" on the intake. Previous owner of these heads who ran a similar cam, and my own numbers say that I should have a lot more clearance.

How should I configure the lifter to measure P/V clearance? I picked up some checking springs, and was going to put the lifter back to normal and measure with a dial indicator on the valve. Will this result in the proper and accurate measurements?

[SkurdalenFox]

On the advice of others who have played with solid lifters and found them inaccurate, I put the lifters back to normal, put some oil in them, and the push-rods. I then gave them a few pumps and dropped them in their bores.

I then tried a little bit different method of tightening the rockers.
I tightened them to zero lash, not by seeing if I could rotate the push-rod by hand, but I hand tightened the rocker bolt to the point where I could no longer rock the rocker off the valve stem or push-rod. I then put a torque wrench on, and in 3/4ths of a turn, the bolt was just shy of 20 ft lbs. I measured pre-load on the lifter at .033". I then turned the motor over 720 degrees while measuring P/V clearance with a checking spring in place of the real spring, and a dial indicator on the flat spot of the retainer just to the left of the valve stem. i.e. in line with the other valves, not above or below the valve stem.

The smallest amount of clearance measured by this method was .152" give or take a few thousandths. I also double checked the tip placement on the valve stem and it still was centered and narrow.

I also tried the above procedure with a slightly shorter than stock push-rod and got .161" of P/V clearance, but it took nearly a full turn to get 18-20 ft lbs. Pre-load was similar to stock length push-rod.

Sounds good huh? Well, if I have measured this way the first time, I probably would have just run the engine like that. I don't know what to believe now though...

That I don't really understand hydraulic lifters I suppose is part of the problem. When the motor is running, how deep will the plunger go? I can push it down another .03" by pushing down on the back of the rocker. Combine that with the existing pre-load and I guess that's the .06" of maximum pre-load. I don't really understand how the lifter remains constant or what prevents the lifter from pumping up and not collapsing at all. In the case of not collapsing, and as measured with the solid lifter, there would be almost no clearance. Should I just junk any concerns I have about the clearance measurements I had with the solid lifter and clay measurement, and run the engine how it is?

[coupe]

The oil in it acts as a VERY TIGHT spring, a cushion if you will. So don't think of the plunger as actually moving up and down, creating slack.

.030 lifter preload sounds great. I don't remember if you go a little more for higher RPM hydraulic cams or a little less.