okay, I degreed this cam one more time. this time i put the camel hump heads on and set the dial indicator on top of the intake retainer. i jimmy up a pointer using a plastic caliper attatched firmly to a bolt where the lower alternator mount goes.

i think i pretty much got the TDC right, i checked it twice and it clocked in at the 340* mark on the degree wheel. using that as a reference for TDC, i proceeded about to find the ICL, or intake centerline.

at first, i tried to take the average of two lifts, .400" on both sides of the lobe. then i tried .450" lifts. but doh, i just remembered that the open and close rates are different.

so, i tried to just plain find where the cam tops out. well, either my setup sucks, or something else is afoot - but i can't seem to precisely locate the peak of the intake lobe. it seems to hover around for a few degrees, so i couldn't get an exact reading. i tried taking the average of when it arrives and departs peak lift, but the final ICL also did not make sense, or much at all.

i believe the cam card is supposed to be 104* ICL, but have had answers from 105* to 107*.

a reminder: to get this cam to clear my intake valves on my 2.02" sportsman ii heads, i needed to retard the cam 4* (i have a three keyway sprocket)

can anyone help?

thanks guys!

Put your dial indicator on the lifter body, your measurements will be more accurate and repeatable.

Find the max lift, and measure 0.050" down from the peak, on either side. Find the center of those two points. That will be your ICL.

i already used the indicator on the lifter, and also tried taking the average of two point on opposite sides of the lobes. i don't thinkthe latter works because the lobes are supposed to have different open/close rates

Gasgzlr, I have the same cam in my 400. I set my dial indicator on the head and used the pushrod as an exension to the lifter. I made sure the dial indicator and pushrod were all in line and as straight as I could. I used both degreeing methods when doing mine and it worked out good. That cam is 104 icl
The 1 thing that had me going was i ended up using the 2 degree retarded key on the crank gear. I checked it many times and thats where it ended up every time.

The opening and closing sides will be most different nearest zero lift, not near the top.

It depends upon the accuracy wanted.
For the most accuracy, you must use a dial indicator, located on the lifter, and parallel to the lifter bore. You must find TDC, and I always find it 3 times, to make sure I know exactly where TDC is.
I turn the engine until I think I am at Max Lift, then I pull it backwards until the indicator has gone down .050". I mark that on the degree wheel---It will be somewheres ATDC--- then turn to max lift and go down .050" on the closing side. I mark that on the degree wheel---It will be a little before BDC.
Average those 2 numbers together---ie, 47° ATDC and 165° ATDC equals 212°, divided by 2, or 106° ATDC. This will be where the top of the intake lobe is.
All these cams are reasonable symmetrical about .050" from max lift.
Having the intake lobe advanced anywhere from 4° to 7° works just fine.

UDHarold

Harold,

I gave up on trying to degree the cam. No matter how many times I did it, it seemed like i was coming up with different numbers each time.

The only measurement I could accurately repeat was finding TDC.

I decided to try your "quick-n-dirty" method, except I used the height difference between the lifters.

I used two machinist's rules, one going across the top of the exhaust lifter, and one going from the first rule to the top of the intake lifter.

At TDC, the exhaust lifter is roughly .028" to .030" higher than the intake lifter. Toss in the 1.5 rocker arm ratio, and this sounds like (at most) .045" height difference. How does this sound?

Thanks

Retarded.......

The intake lifter should be .025"-.035" higher than the exhaust. When the exhaust has more lift at TDC, the cam is retarded. Check to make sure you're not off a tooth, although I think that would have had more lift.....
Sorry, I just went back and read your initial post again. You installed the cam retarded, and that's what the lifters are showing. I do not understand why you have no piston-to-valve clearance, that cam generally has no problem with that.
When you find TDC, move your degree wheel so that TDC is set on 0, then try it again, and let me know.....

UDHarold

Harold,

I gave up on trying to degree the cam. No matter how many times I did it, it seemed like i was coming up with different numbers each time.

The only measurement I could accurately repeat was finding TDC.


I just went through this, trying to do my first cam degree job. Coincedentily I installed this exactly same cam, 401A6LUN. I think I finally got it though.

With the cam installed straight up I came out with a 106 ICL installation, using two different methods to degree it. From the dynamic compression ratio calculations that another member did for me, having it at 106 is a little safer for me on pump gas than 104 anyway, so I was happy with that. I don't think this will make a significant power difference, at least it shouldn't be noticeable on a street car with street tires and a stock converter.

When I installed it, I had the engine at TDC and left it there (and left the degree wheel and pointer set up, dont disturb them!) , the round dot on my crank gear was pointing straight up. I installed the cam and figited with installing the cam gear and chain until I had it set where the round dot on the cam gear was as close as possible to pointing directly down at the dot on the crank gear. Then I torqued the cam gear bolts.
Next I put in a lifter on the #1 intake lobe, which had only a very light amount of lube on it. Here was the trickiest part, I set up the dial guage with a pushrod between it and the lifter, and aligned it as best I could so that it was perfectly in line with the lifter.

I then tried degreeing the cam both using the '.05 lift from the base circle' method, and '.05 below max lift' method. Both ways I came out with 106 degrees ICL.This took me 4 days along with a couple of threads here to vent my frustration :). If you so much as fart around the pointer wire or your degree wheel you can throw it off and have to start over. At one point I was so close, and accidentily whacked the pointer with my arm and moved it a couple degrees off. Had to start over with much cursing :(. Patience is the key here :).

Harold, is there any problem with using 1.6 rockers on this cam? My machinist who set my heads up said I should have no piston-to-valve problems using them. Am I losing power with the 1.6 rockers? Truth be told, I ordered the 1.6's at the same time I ordered the cam, then when I got the cam I saw that 1.5's were recommended on the cam card.

Brian,

The 1.6s work perfectly, and I recommend them. If you have just 1/2 set, put them on the intakes, which provide a bigger BHP/torque gain than putting them on the exhausts. Max power is with 1.6s straight across.....

UDHarold

harold,

i tried it again.

i used a TDC piston stop and located TDC twice, and found the bottom edge of my timing tab to point to the 9* mark on my balancer at TDC.

at TDC with the crank gear at "-4", the exhaust lifter is higher than the intake lifter.

at 4* ATDC with the crank gear at "-4", the lifters were too close to tell.

at 6* ATDC with the crank gear at "-4", i finally saw clearance under the machinist's rule, and found it to be in the neighborhood of .012" in lifter height difference. .012" went, .015" did not, using a feeler gauge.

at 7* ATDC with the crank gear at "-4", i had about .022" of clearance under the rule.

how does this sound, harold?

remember, my crank gear is at "-4" because if i set it to "0", the intake valve opens too fast for the piston.

gasgzlr, I am not sure if this is relevent or not but after following this post I went and measured mine this a.m. using "Harolds quick n dirty method" I started second guessing myself. I brought #6 to tdc and roughly measured #1 intake and exhaust at the retainer to the head. Intake was definatley closer. I have my crank gear at -2*. Thats where it ended up after degreeing it many times. Not 100% sure if mine is wrong or right but I do know that it runs great and I will probably leave well enough alone. I have 20cc dished pistons and my piston to valve clearance was , on the tightest one about .149
Hope you get all this ironed out soon
Good luck!!

gasgzlr,

If I am following you correctly, it is probably in the engine 3° to 4° advanced, and will probably run OK there.

UDHarold

hm, i'll take your word for it.

i'm just confused because you say it is 3-4 degrees advanced, which is as said on the cam card, but the timing chain i'm using is set to "-4". must be the timing chain or something that is making it act 4 degrees slower. that is probably why the cam won't clear at the "0" setting, because it's actually advancing it 7-8 degrees...?

Are you still involved with Ultradyne? I noticed the name is around again. I noticed it is listed as your web page on here. I just want to know if the new Ultradyne has anything to do with the old one or are they just using the name.

I have one of the old Ultradyne 280/282 solid cams in my 383 and I like it. Wish I had the total specs on it. I got it from a guy named Tim Gantt who lives in Marietta, GA. He supposedly was one of your better customers when you had the biz going. I was disappointed to see it shut down. I understand why you did that though.

Thanks for your contribution to the sport.

Sgt Barks,

It depends on whether I am UltraDyne, or the equipment/masters are......

The equipment and masters, etc, all the contents of the building, were bought by Bullet Racing Cams. Tim Goolsby, who had been my right-hand man for 21 years, went to work for them---He had earlier told me he would never work for any cam company other than UltraDyne, so he's still there. Earlier, Tommy Stoddart, my head finisher, had gone to work for Bullet.
At Lunati, I have Mike O'Neal, my shop foremen and other right-hand man for 19 years(Have you ever known a left-handed man with 2 right hands?). Steve Slavik, one of my old salesmen (13 years) is at Lunati also. He's extension 1126.
I did not shut UltraDyne down. The IRS did, and I am still arguing with them. Hopefully, it will be settled this year. I want to pay them, but I cannot pay them what all they want within a 5-year time span.
It is almost as if Lunati and UltraDyne exchanged cam designers. Lunati's old cam designer owns 5-10% of Bullet, and UltraDyne's old designer(ME...) has a 5-year agreement with Lunati. It will be interesting to see what happens over the next few years. If all the racing solids and rollers I have designed work as good as the hydraulics/hydraulic rollers, things will be looking good.
Time will tell.....

UDHarold

BTW, if you loved Lunati's OLD cams, you'll love UltraDyne's NEW cams.....

LOL. So I guess if I like Ultradyne's old cams I will love Lunati's new ones too huh.

Sorry to hear all that. I hope you get it all worked out and it doesn't hurt to bad.

Take care.

"I would suspect the cam is not where you think it is. Use my 'quick & dirty' method to check it. With your valve cover off, turn #1 cylinder to TDC. Either both valves will be on the seat, or both valves will be a little off the seat. If both valves are on the seat, turn the engine another revolution. Now both valves should be off the seat at TDC. I use something like a 6" Machinist's steel rule, and measure from the top of the retainer to the spring seat. The intake valve/retainer should be about .025" to .045" CLOSER to the head(I told you it wasn't an aggressive cam...). If it is .060" to .100", it is too far advanced, and that is the reason for your clearance problems. Re-checking and re-degreeing the cam should solve your problem. If this does not, you may need someone to 'eyeball' it."

^^ This is where i'm confused: "The intake valve/retainer should be about .025" to .045" CLOSER to the head"

When I took the measurements at TDC, the intake LIFTER was about .028" BELOW the exhaust lifter. This tell em that when the valvetrain is assembled, the exhaust retainer will be .040" or so CLOSER to the head than the intake retainer...?

Because we want the intake retainer (when assembled) to sit about .030" closer to the head, I tried to find where I could get the intake lifter about .020" HIGHER than the exhaust lifter. This did not show up until about 6* after top dead center...

So, I figured that had I installed the cam with the crank gear at "0" instead of "-4", the cam would not satisfactorily be advanced at the "0" position, which unfortunately already causes the valve to hit the piston.

I think maybe my pistons might not be notched enough/correctly? I have speed pro hypereutectics, H616CPs. They are flat tops with 4 eyebrows in them. Here is the picture of the pistons from a while back:

http://image36.webshots.com/36/9/81/75/290898175MJyXyi_ph.jpg

Do you think they could be the problem? I've seen pistons with different eyebrow configurations that look liek they may be a better match. would this probably be the case?




edit: i finally got my pushrods in the mail, i assmebled the valvetrain as-is. the crank gear was at "-4". i did not get the intake retainer .026" closer to the head until 6* ATDC.

gasgzlr,

My suggestions:
1.---Start over. Find TDC, and make TDC on your degree wheel agree with your TDC indicator/marker. TDC is 0°. Check it again, and then a 3rd time. I always do everything 3 times in a row when degreeing a cam to make sure that all three results agree.
2.---With #1 having just fired, put your cam in 'Dot-To-Dot', with the dot on the cam gear down and the dot on the crank gear up. Use the '0' setting.
3.---Now turn the crank 1 turn, and check the lifter heights now. The intake lifter should be about .025"-.035" higher than exhaust. This will mean the cam is advanced properly, and the engine shouold run good.
4.---Let us know what happened after your measurements.

Thanks,

UDHarold

Harold, it looks like at TDC, the exhaust lifter is definitely the higher lifter.

My measurements:

At TDC, exhaust is higher by about 026"

since my crank gear is at "-4", i measured at 4* psdt TDC to see what it'd be like had i used "0" on the crank gear.

At 4* past TDC, the lifters were about even.

Just for kicks, i tried the cam at 6* past TDC.

At 6* past TDC, the intake lifter was higher by .012"

I wanted to get the .025"-.035", so I tried finding where i could obtain that figure.

At 8* past TDC, the intake lifter was higher by .026"






Question #1 = So, I'm reading that even if I installed the cam using the "0" mark on the crank gear, it still would not have been advanced enough, until i used a "+4" or so on the crank gear (if it had it)... What do you think?

Question #2 = It sounds as if the cam came to me ground straight up? Do you guys do that, or put 4* advance in? Does Lunati make their own cam blanks? If not, does the supplier supply the blanks with the dowel pin at 4* advanced?

Question #3 = What should I do now? :-\ If there's nothing wrong with my combo other than too big of a cam, Should I just give up and buy something smaller? I have a Crane 284 Energizer (yeah, sorry lol) still brand new sitting on the shelf from a while back... (228* at 050, 284* seat to seat, .480" lift, 112* separation), but I would need new valvesprings for that one :(






Again, here's my combo if you are going to suggest a new part...

Holley 650 double pumper or 750 vacuum secondary
Edelbrock performer RPM
world sportsman II 72cc heads 200cc intake runner 2.02/1.60 valves
or 461 camel hump heads with 64cc chambers, stock valves and springs

406 short block
speed pro hypereutectic H616cp 4 valve relief pistons -6cc dish approx. .030" into the bores, forged I beam rods, scat 9000 steel crank

1.75" long tube hedman headers, and i'll eventually get a dual 2.5" exhaust system (i have 3" glasspacks right now that bolt to the headers)

'69 chevy nova, th350 with either 2400 or stock stall
i have a 2.73 now... but since i've given up hope of going to the power tour (doh) i'll be swapping in any gear i want soon, probably a 3.55 or so in a couple months.

Sounds like it is well retarded.

gasgzlr,

What it may mean is that you are 1 tooth off on your timing chain, which will give you the results you are seeing......
For #2, NO cam company, like Comp Cams, Isky, etc, make their own cast cores. Crane is the exception, and they buy the castings from the same place that makes the castings for the other core companies. The core companies make ground cams as well as unground ones, but sell only to big companies like Melling or Elgin, or PAW, etc.
Most cast cores are made with a 2° or 4° pin off-set, and the steel billet cores likewise. Crane and Cam Motion are the only 2 cam companies making steel billet cores, the rest of the cores come from Camshaft Machine or Engine Power.....
There is nothing wrong with your combo, as long as your springs will handle the lift, and your rods will clear the cam. Unless the cam is made on a small base circle, I cannot garauntee that it will clear the rods. If the rod company said it would clear, that's what they said.....
If you are off a tooth in your timing gear set, that might be the cause of your clearance problems. I normally do not have problems with that cam.

I hope this helps..... I have to get off for a while, so I won't respond until much later...

UDHarold