Can someone please help me with a camshaft reccomendation? I was looking at some of Lunati's new camshafts, but I am looking for some opinions. I heard that Harold from Ultradyne was on this board, which is why I decided to bring this discussion here. Thank you!

10:1 Dished 400 Small Block Chevy
5.7" GM rods, GM 400 Crank Shaft
Sportsman 2 Heads with valve job and bowl work
2.02" 1.60" Manley Valves
1.44" Dual valve springs
Holley Z28 Intake
Holley 750 cfm carbeuretor 4-barrel
Hooker Competition headers
Turbo 350 with a Transgo shift kit
Hurst ProMatic Shifter
3.55 gear Auburn positraction Rear End
25.2" Rear Tyre size
3100# 1973 Nova

I was considering the new Lunati 401A6 Camshaft. According to them it is a two week order and I could grind it any way I want. I am thinking of having it ground to 108 seperation angle with 108 intake centerline. I saw another post about this camshaft and would like to know how well it would work with my current setup.

I am stepping up from a 8.5:1 setup with an Edelbrock Performer Plus and a 3.08 (?) open gear.

Thats the cam that Harold recommended for me. I have 10.1 compression and 3.42 gears. He'll probably offer the same.
Still waiting on it though, so I cant tell you if its good or not, but I suspect it'll be everything I hope for and more.
MaTt

im no expert..but I would think with a 108LSA you would have it on a 104ICL

Originally posted by bigjimzlll:
im no expert..but I would think with a 108LSA you would have it on a 104ICL =
ditto,, at least 104, I'd go to 102 with Harolds lobes. ;)

I spent some time reading what went on recently on the site and I found Pat Kelley's DCR Calculator. With the 401A6LUN ground at 108/108, I would have just under 8:1 DCR, which I feel could run 89 octane. At the "stock" 110 spread and 104 c/l, it raises it to 8.2:1 DCR. How accurate is this calculator? I would assume that with Harold's big duration that it would bleed off cylinder pressure more effectively? Or am I wrong in thinking this?

I have 91 octane in California. With gas prices lately, 89 would be nice, though not necessary. I don't think I wouldbe able to run 87 without a really big camshaft, in which case I would end up needing 3.73s or more.

How does my package sound to this point? I am thinking of getting rid of the cheap Hooker headers and obtaining some 1 3/4" headers. Would it be worth it on a 6000 rpm motor?

I think that advances the intake closing point about two degrees, that's why the DCR went up.

108/108 vs 110/104.

I think if it was 108/108 vs 110/106, the intake closing point would be the same.

Pat, you around here??

pdq67

Well, if the cam is ground to 108 versus 104, is that not 4 degrees advanced? Lobe seperation... Is that measured 110 or 108 degrees from the intake lobe centerline?

This is for everyone......

It may be best to calculate your DCR and tell me where you want to close the intake valve, and let me choose a cam grind from that point. My cam designs HAVE NOT performed very great when straight-up. Both dyno-tests and track tests have shown 4 to 7 degrees is the correct advance for best over-all perfomance.
You would like a cam that gives your desired DCR and was also advanced 4 to 7 degrees better than a cam that was straight-up.

UDHarold

Make sure you have enough stall to handle 108. Remember that as you tighten separation you narrow the powerband. This is especially noticeable on the bottom end. You'll need adequate stall for a 108 LSa cam. If its a driver, I'd opt for 110.

The intake closing point determines the DCR regardless of anything else. So a 108 LSA and 108 ICL will close the intake 4º later than a cam on a 110 LSA installed at 104º. The 108 ICL regardless of the LSA will have a lower DCR than the same duration at 104 ICL. Notice in the calculator that the 104 ICL has an earlier intake closing. This traps more mixture in the cylinder and raises the DCR. Numerous dyno and track test show that advancing the cam, while trading some top end, produces more power overall.

Also, I'm not sure you could run 89 octane at 8:1 DCR. You can try it but don't be surprised if you need the good stuff. Most of the older high compression engines of the past ran larger cams that produced DCRs in the 7.5 range. These needed high octane. For 89 octane, I'd look for a DCR in the low-mid 7's DCR. However, there are a number of other factors that can influence octane requirements like chamber design, quench distance, head material, and the overall efficiency of the engine. I like Harold's idea of telling him what intake closing point you want and letting him work out the rest.

Originally posted by gasgzlr:
Well, if the cam is ground to 108 versus 104, is that not 4 degrees advanced? Lobe seperation... Is that measured 110 or 108 degrees from the intake lobe centerline? =
gasglzr,
the only thing ground into a cam that cannot be addressed when you install it is the lobe separation.
You can put the intake centerline any place you want by degreeing the cam properly.
You cannot assume that a cam with 4 degrees of advance from the grinder regardless of who will install into your engine at 4 degrees of advance.
There are just too many variables that can influence this, some being, the cam itself, where the lifter bores are located in your block, the gears, the location of the crank key, how the crank was ground in relation to this key,,,, just to name a few ;)
When you install a performance cam take the time to degree it correctly.
At least you will know where you started :D

Thank you everybody for the replies.

Harold, I used Pat Kelley's program to determine a good intake closing angle. To obtain a near 8:1 DCR, I used a 64 to 65 intake closing angle.

By the way, yes this car is a driver. I have no vacuum dependent devices other than the standard GM HEI ignition and transmission. Probably the 110 lobe seperation angle will work better. What about 112? Or would that just be a waste of useful overlap?

Remember since the Lunati cam core has 4* build in from the manufacture don't get confuse and think that you need an additiion 4*, which would put you at 8* total advance. If you want 4* install the Lunati cam straight up on the timing chain, which is 4* on the cam.
Now that was confusing :D

I understand what you mean. The 401LUNA6 camshaft is ground to a 110 spread and 104 intake c/l... This is a 6 degree advance, correct?

Originally posted by gasgzlr:
I understand what you mean. The 401LUNA6 camshaft is ground to a 110 spread and 104 intake c/l... This is a 6 degree advance, correct? Correct but you still need to check it when you install it ;)
Also, this is an answer to one of your earlier posts.
When you widen the lobe seperation to 110 or 112 from 108 with the same lobes you will have less overlap not more.
Are you confused yet :D

No, not really smile.gif I was asking if I should widen the lobe seperation to increase the driveability factor. Then again, all of Comp Cams' Xtreme series are supposedly very streetable and pack a 110 spread, so I think running a 110 Should be fine. My Performer-plus cam came with 112 and had some nice rumpity nump with glasspacks, so I hope for more rumpity bump bump bump with an Ultradyne camshaft :D

p.s. - The gist I am getting (based upon Harold joining Lunati, and Lunati releasing what looks like 30 camshafts as "new") is that Harold's Ultradyne camshafts and lobe profiles were carried over to Lunati's inventory?

Gasgzlr,

The 401A6 put in the engine on a 104° ICL gives 64° ABDC, the same cam on 106° ICL gives 66° ABDC. A 108 LSA advanced 4 gives a 104 ICL, so does a 110 LSA advanced 6. A 110 LSA advanced 4 gives a 106 ICL. Most 108 LSA grinds of mine advanced only 2 to a 106 ICL generally don't perform as well as those cams installed 4 to 6 advanced.
What this means is that if you decide on a 108 LSA, you'll have to run the cam 4 ahead, for a 104 ICL and IVC 64° ABDC. If you decide on a 110 LSA, you can run the cam 6 ahead for a 104 ICL and IVC 64 ABDC, or 4 ahead for a 106 ICL and IVC of 66 ABDC.
All these combos work......

UDHarold

UDHarold

Uh oh, I think you just lost me Harold, lol.

I used Pat Kelley's program to determine that 64 Intake Valve Closing was what I needed to run an 8.06:1 DCR. When I put in the 276/284 401A6 camshaft at 110 seperation and 104 Intake C/L, it gave me 62 ABDC. Is the program wrong? I would probably take your word for it if you say it's 64 degrees when used with a 110 seperation and 104 C/L.

If the rest of the combolooks good to everyone, I think I'll give it a shot, hopefully I have the right cam?

Now if only I could find traction... :eek:

Harold, I am running a polished single valve spring with a 1.750" installed height (I think) with 145# of pressure, and about 345# of pressure at 1.250", coilbind 1.065". Would this suffice? I can't remember my exact installed height, they came with my heads and I never really measured them.

Thanks!

gasgzlr,

Pat's DCR program is correct for SYMETRICAL cams.
I don't do symetrical cams, but only UNSYMETRICAL ones.
The 276 opens like it is a 272, and shuts like it is a 280. All cams in the same family work the same way, my 288 solid (UF1) thinks '284 open, 292 close'. My 288 ROLLER (UR10) thinks '282 open, 294 close'. Most of my cams are in these general ranges.

UDHarold

Oh, cool. I didn't know they were asymmetrical. What do you think of the valvesprings I currently run in my heads?

Well, you recommended the 401a6 for me too. When I changed the duration figures to what the cam is as stated above, my DCR changed from 8.1 to 8.27. Am I in trouble now?

MaTt

"Remember since the Lunati cam core has 4* build in from the manufacture don't get confuse and think that you need an additiion 4*, which would put you at 8* total advance. If you want 4* install the Lunati cam straight up on the timing chain, which is 4* on the cam."
very good point deeboo this was a topic that we discussed awhile ago that had more than a few confused inlcuding myself. also make SURE you degreet that cam!! it isnt' that hard once you get the hang of it, if you don't you run the risk of installing a cam with no advance ground into it. these cams have been circling around lately :D all you need is a wheel dial indicator and a piston stop

I understand all LSA and IC/L issues. I was asking about different LSAs because I wasn't sure whether I wanted 108 or 110, and I asked about 106 IC/L because I thought it was a symmetrical Camshaft under Pat Kelley's program and needed 2 degrees retarded from stock to obtain the 64 IVC specification. Base upon Harold's replies, I will keep the 110 LSA and 104 IC/L.

Now about that valvesping I'm running... :confused:

By the way, Harold, Is it worth the extra price to run a solid lifter with the EDM hole in the lifter face? Would I need a High Volume Oil Pump? Does this affect valvetrain reliability/lifetime? I know this was in a thread before, but I would like to hear it straight from the horse's mouth.

Thank you!

gasgzlr,

EDM holes----No, that profile has run for over 20 years without EDM holes being required.

High Volume Oil Pumps----Because this 'Horses's Mouth' doesn't want to look like the other end of the horse, I'll pass. However, high-volume pumps DO put a higher load on the distributor gear....

UDHarold

The reason I asked about the high volume pump is because there was another thread asking about mechanical lifters with EDM holes, and someone replied about running a high volume pump.

What are the spring pressure requirements of this cam? With the right installed height I believe I can obtain a 140# seat pressure with approximately 350# of open pressure at max lift. Would this be okay? or should I look for a different spring?

Originally posted by gasgzlr:
The reason I asked about the high volume pump is because there was another thread asking about mechanical lifters with EDM holes, and someone replied about running a high volume pump.

What are the spring pressure requirements of this cam? With the right installed height I believe I can obtain a 140# seat pressure with approximately 350# of open pressure at max lift. Would this be okay? or should I look for a different spring? =
I like your spring.
350 open is fine. I don't concern myself much with seat pressure near as much as open pressure.
You don't really need 140 on the seat but it won't hurt anything.
Just limit the open pressure to about 350 max for almost all flat tappet use.
There are exceptions but that's not what we are talking about here.
On the EDM lifters, if you run them I feel a hi volume pump is a good idea as you have added 16 new oil leaks to the system.
I personally like the EDM lifters but have run for years without them without problems.
I now use them on most flat tappet solids & groove the lifter bores on others & on hyd stuff.
If Harold says you don't need them with his lobes & you are using the recommended lifter I would be the last to disagree.
He knows what works with his lobes.

I use Isky's lifters in most applications because they are Stanadynes which as far as I know is the last lifter manufacturer left in the USA.

Right, I was looking at non-EDM lifters this morning, and Isky lifters were around a hundred... The Isky EDM lifters were 180 bucks off their site! Ouch!

Where do you guys get your lifters? Usually I see solid lifters go for 50 60 bucks...

Originally posted by gasgzlr:
Right, I was looking at non-EDM lifters this morning, and Isky lifters were around a hundred... The Isky EDM lifters were 180 bucks off their site! Ouch!

Where do you guys get your lifters? Usually I see solid lifters go for 50 60 bucks... =

I can probably save you a buck or two on the Isky's. ;)
email me if you like.

Another question... I recently bought Comp Cams "How to Degree a Camshaft Video" - now I need the materials to degree a cam. Is there a budget kit out there for under $100? I would need all the tools for degreeing a cam, including a dial gauge.

Originally posted by gasgzlr:
Another question... I recently bought Comp Cams "How to Degree a Camshaft Video" - now I need the materials to degree a cam. Is there a budget kit out there for under $100? I would need all the tools for degreeing a cam, including a dial gauge. =
Comp has one for about $140

You've got mail!

$140... Ouch! I just spent lord knows what on the 401A6 camshaft. I just realized that I never asked how much it was when I ordered it from Danny at Lunati! :eek:

I just ordered my 401A6 from summit and they quoted me $165.

MaTt

Gasgzlr, check out Competition Products for the EDM lifters, 89.00 a set. 1-800-233-0199

Strange, Summit said they couldn't order it for me... :confused: That bites, I'm trying to get as many parts as possible from the fewest places to save on shipping... Doh! Doesn't it cost more to buy from the manufacturer too?

I had to talk to a tech at SUmmit and then I had to call Him back the next day so he could call Lunati and put the specs into his system. Idont know, but he said it would be 2+ weeks.

MaTt

Cool... Lunati said 5 days to grind, 2 days to ship...I guess I'll find out soon enough ;)

gasgzlr, run a search on Harold's quick and dirty cam degreeing method. It's actually a checking procedure, but I 'degreed' my cam that way ( wicked easy) and then checked with a dial. Right on. Without the dree wheel/dial, total cost for parts is one set of cam bushings. And I wouldn't open the package until I checked first. Might cost you $0.

Originally posted by gasgzlr:
Cool... Lunati said 5 days to grind, 2 days to ship...I guess I'll find out soon enough ;) ;)

Ha ha, I got back to them. $163.95 for the cam and $9.13 for shipping. Hopefully It'll be there next week!! :D

UD Harold... looks like I was able to find some Ultradyne solid lifters NOS part number VT1992... should I grab them to work with the camshaft I ordered? Or would some Iskys be better? I don't know much about lifter design, unfortunately...

gasgzlr,

VT1992s were my lifter of choice for 20 years....

UDHarold

Woo Hoo! I got the cam this morning... I woke up, walked outside for the paper, and Mr. UPS shows up, cam in hand :D That was WAY quicker than I thought, especially since I ordered it last Wednesday!

I also scored some new-in-box Ultradyne lifters to go with he camshaft graemlins/thumbsup.gif

I'll let you know the results maybe in a couple weeks, as soon as I find someone in my new town willing to lend me a hand, haha!

graemlins/thumbsup.gif