Flareside

Well, I know this is opening a can of worms, but it's a nice relaxing Sunday so I thought I'd ask anyway ;) I've been toying with about a thousand cams in Dyno2000. My main concern is how much low end is usable around 2000 rpm with street tires, since I've never driven in anything even close to this. How much is too much? I've got cams that yield around 450 lbs. at 2000, and others that yield around 600 lbs at 2000! All make over 650 peak HP, some are over 700.

Here are a few charts that I've been debating. Two are solid rollers (Crower and Comp), and the others are UltraDyne solid flat tappets. I really like the "curves" of the roller, but I'm not sure I could ever use the extra power it will provide. I've also heard of lifter failures, pounded valve seats, and high guide wear. Definitely don't want to hurt my new AFRs! How often do you roller guys adjust your valves? I usually rack up about 1500-2000 miles a year. How long will you run the lifters before you replace them, assuming there is no visual wear? Opinions are always welcome...

Other useful information: 3400 lbs, Richmond 5 speed, 3:55 rear (probably changing to 3.08 in the future), 2.5" exhaust (going to 3" undercar), 2" headers, Holley EFI, rectangular port AFR heads, 10.3:1 compression.

The dyno charts are big, so I didn't want to directly post them. Here they are:

Crower 296R solid roller 256I, .580 lift, 266E, .588 lift, 112LCA. http://members.bellatlantic.net/~kay...r296roller.jpg

Comp XR292R solid roller 254I, .660 lift, 260E, .666 lift, 110LCA http://members.bellatlantic.net/~kay...CompXR292R.jpg

UltraDyne 282 solid flat tappet 248I, .570 lift, 255E, .576 lift, 112LCA. http://members.bellatlantic.net/~kay...mp/282.292.jpg

UltraDyne 288 solid flat tappet 255I, .612 lift, 263E, .630 lift, 110LCA http://members.bellatlantic.net/~kay...mp/288.296.jpg

UltraDyne 292 solid flat tappet 259I, .625 lift, 267E, .625 lift, 110LCA http://members.bellatlantic.net/~kay...mp/292.301.jpg

It's interesting that the Crower roller makes almost the same power as the Comp roller with much less lift at the valve. It's down about 10 HP on top, but low end torque is up and durability should be better. In the solids, I'm leaning toward the Ultradyne 282 because the low end torque doesn't drop off so severly like it does with the larger 288 or 292.

So, what do we do?

-Joe



[Modified by Flareside, 3:01 PM 2/3/2002]

ML67

I'm running the XR292 w/ 112 LSA (+5 degrees advanced) w/ my 540. On a chassis dyno, I made 560 RWHP @ 6300 and 550 RWT @ 4400 on pump gas through the mufflers with a lean A/F ratio (13.9:1). I like this cam, although I'm biased towards rollers myself. Its hard to over cam a 540 as long as you have the heads for it.

Street rollers don't require the hellacious spring pressures of a racing roller, with opening & closing ramps more conducive to low rpm longevity.

Jim Moore (427Hotrod) made over 600 RWHP w/ open exhaust with his 540. His cam is even larger yet he made his peak HP @ 6100 rpm. Which AFR heads are you getting? The bigger the port (and attendant flow) the more you will be able to exploit the high lift offered by the Comp or equivalent roller.

I make approximately 1" vacuum for each 100 rpm increment (10" @ 1000 rpm).

BTW I'm in the process of installing a RG 5-speed and 3.08's this winter. And I'll also retard my cam 2 degrees as I have too much low end. All that impressive torque just goes up in tire smoke. You'll love it!

Take care,

Mark




[Modified by ML67, 2:17 PM 2/3/2002]

bence13_33

Joe:
Still hard at work I see :). I'm glad to see that you went with the AFR heads...the flow numbers on those heads are just incredible! (I can't wait to get my hands on a set)

With 600 Ft. Lb. of Torque @ 2000 RPMs....I see a cloud of tire smoke. By the way what tires have you decided to run? The old saying has always been "Horsepower is for bragin' ; Torque is for dragin". I really can't see you putting that 600 Ft. Lb. of Torque to much use (except in a burnout competition). If it were me (I know I can hear the snickers already :) )....I would be building for horsepower. That 540 is going to have more than enough bottom end. Why not take some of the stress of the drivetrain and put the power up higher in the RPM range? What do you think?

Flareside

Mark, I've still got my Richmond sitting in the garage as well. I'm planning to install it along with the 540 sometime during the next century...

So, I take it you would go with the XR292 again? Would you go with the 112 LSA again or keep the "off the shelf " 110? My heads are the AFR 325cc models, with 2.3" valves and 119cc chambers. 1.550” OD roller dual valve spring with dampner, 240 lbs. on seat, .750” maximum lift. I placed my order last week, but they won't be here for a few weeks.

Bence, the AFR flow numbers are good, but not really that much better than anybody else with a decent raised port. They use a 4.5" bore fixture when they flow their heads, and all the heads tested at CHP were done on a 4.25" bore fixture, so you're not comparing apples to apples. AFR has updated flow numbers on their new web site that were done with a 4.25" bore, but only for the 315 head at the moment. They compared the 315 CNC head to everybody elses "as cast" head, which really isn't fair either. Dart makes a CNC 335 head that flows great too, but the CNC process puts all these heads way out of my price range. That said, I went with the AFR because the do flow better than anything else with a .3" raised port. The others use a .6" port which will be harder to fit in a C3 (Canfield, Brodix).

I have BFG Radial TA 245/60-15s all around with about 500 miles on them right now, so I'll probably just run them for a while (or melt them :eek:)

As far as the low end torque, I just don't know what I should be looking for. This engine is sooo far removed from what I'm running now, that I don't really have any practical experience. Is 450 lbs. of low end the magic number, or is more usable? I just don't know... Mark's response tells us that 520+ is probably too much.

Thanks guys!

-Joe


[Modified by Flareside, 3:31 PM 2/3/2002]

mountainmotor

You might try the 288 and 292 cams on 112 and 114 to see what you come up with.If you like what you see,where you install the intake centerline at when degreeing can be decided on later.The injection should help over a carb in respect to the possibility of detonation with the wider Lobe Center Angles and your compression


[Modified by mountainmotor, 2:40 PM 2/3/2002]

ML67

I like the XR292 and would probably keep it on the wide lobe centers. All that torque down low is tough on tires! Also I want to give 600 RWHP a shot in the spring, so retarding the cam a couple of degrees will help. You go much shorter than 255 intake duration @ .050 and you will make too much torque too far down the rpm scale to exploit on the street! These big engines & heads are very forgiving and thrive on aggressive valve timing.

The only thing I might consider changing is actually a bigger cam with an additional 5 - 10 degrees .050 duration. I have the engine out right now, but most likely I will keep my cam and just back it off to a 109 intake centerline instead of the current 107 centerline.

These 540's are great -- you will really like your setup no matter which way you end up going!

Take care,

Mark


[Modified by ML67, 3:46 PM 2/3/2002]

ML67

And I run 40 degrees timing on pump gas -- no detonation even w/ the lean A/F ratio. Jim Moore (427Hotrod) and another friend w/ a 502 and Brodix heads both run 40 total timing on pump gas. The big bore and Brodix combustion chambers apparently need a bit of lead to maximize performance. Not sure if the AFR heads will also require similar advance.

Take care,

Mark

Flareside

More duration, huh? Hadn't really thought about that. The XR292 is the biggest street roller Comp sells! :eek:

Jim is a great guy! He's given me volumes of advice and help for my buildup.


[Modified by Flareside, 3:59 PM 2/3/2002]

69ttop502

Hey Joe always love following your posts. I am very curious about the durability issues of solid rollers on the street also. At some point the cams got a bad rap I guess from some lifter failures and related problems with low speed oiling. I know comp has that endurex lifter for the street cams and I guess this was to solve the low speed oiling issue. I like the idea of not being able to screw up the break in of a roller as opposed to having to run in a flat tappet in on weak springs first but I would really like to hear about the longevity issue. I was reading where Lingenfelter says although in reference to small blocks to never be afraid to run a solid roller on the street. I am dynoing my car on Tuesday morning and after that the heads are coming off and a cam change is in the plan, but I really want to make the right choice. Thanks.

Flareside

Bill, where are you having it dyno'd? Porting the heads?

Gordonm

Joe, regardless of the cam you use you will be able to roast those tires or any tires with the torque of a 540. Rollers in my opinion are the way to go. Much more torque and HP with less duration therefore making it more streetable. With fuel injection you are going to have gobs of torque. I think I will invest in the rubber company of your choice! :yesnod:

Flareside

Gordon, it sounds like somebody's getting ready for a roller, and it ain't me :lol: :lol: :lol:

You're right, this thing should have more power than I'll ever need no matter which cam I choose, but we have to do something until the game comes on :cheers:

Flareside

I guess I should start looking for a hardtop like you, huh? :lol:

Gordonm

If you want to race at Etown. Atco has said nothing to me and I've been there 4 times without the hardtop. Etown is a little tougher with the rules

Flareside

I wonder about the new road course. Think they'll let ragtops run?

Gordonm

Good question.

69ttop502

Joe I am having it dynoed in Walden NY. Yea when this is done I have some work to do. I am going to keep the iron rect. ports and work on them a little and the cam, just can't friggin decide. Hey why dont you just run your Merlin at 509 cubes, that should kill some low end. Good job on the AFR's. I will look forward to following your builup. Let me know if you know of any reputable machine shops in the North Jersey area. I know with my 502 with the mild cam it has in it now that is rated at 515 lbs. ft. it is already too much to hook, although I only have 225's on it. The good thing is I know I won't break anything.

Flareside

Walden, huh? I go to the motocross track up there all the time. Let me know how knowledgeable the dyno guys there are, I need someone to dyno tune my EFI when it's done.

I've talked to a few local machine shops, but haven't found anyone I'm happy with yet. The search continues... A few people have recommended Sirico Bros. in Ledgewood to me (about 40 miles west of the GWB), but they have a 2 month wait :(

Flareside

Wow, 40 degrees Mark? Do you also run a vacuum advance?

I have a set of SRP "10.25:1" pistons with 10cc (their number) domes.

-Joe

VETMANIAC

Flareside,

I have been rethinking my cam selection since I have the Holley EFI planned for installation at a later date. I am currently running a Schneider Roller Hydraulic: 232/238@.50, 585/595 lift and 110 Lobe Sep. I was considering making the switch to a solid roller, but after speaking to 4 different cam manufacturers I decided against it. I drive the Corvette much more often than it sounds like you are planning to. I described how I use the corvette to all of the cam companies as follows: Driven to work 3 to 4 days per week, 20 to 25 miles each way, heavy stop and go traffic, driven in and around Dallas (100F+ summers) and I make occasional roadtrips of 400+miles each way (3 or 4 times per year). Every one of the cam companies I spoke to including Comp, Crane, Lunati, Cam Motion, etc. all said exactly the same thing; do not run a solid roller. Comp said that even their new Endurex line would not put up with the kind of "Street Driving" that I do. Now having said all of that, if the kind of driving you described is really what you will do (1500 to 2000 mile per year) then you should be just fine with a Solid Roller. I plan on trying a Lunati EFI grind next: Hydraulic Roller, 234/244, .629 IN/.612 EX and 114 Lobe Sep. Regardless of which cam you pick, you may want to move the Lobe Separation out to 114. EFI seems to work better with wider Lobe Sep. Good luck with your build up and please continue to keep us posted on your progress.