Update on results with Cam Motion cam

86Cobra · 10-17-2002

Based on my obviously inaccurate seat of the pants meter I had recommended Cam Motion to others on this board. Well I finally got it on the dyno and the results were very disappointing. I made 12 pulls and the best was 339 rwhp at 5500 rpm and it floated the valves at around 6200. This is a nice number for 5500 rpm but this motor should keep pulling above 6000 and shouldn't float the valves at all.

I spoke with another respected cam grinder who said that Cam Motion grinds excellent solid lifter cams but isn't very good at hydraulic rollers. He said they don't get the ramp rates right and that's why it floated the valves. Cam Motion also is too conservative with their LSA on efi cars. This cam has a 111.5 lsa and really should be in the 108-109 range. That's a big reason why the power peaked so low.

He also said this cam (235/237, .567/.574) is way too small for my goals so it's time to step up.

I know the intake is a limiting factor and I will be upgrading to a Holley when I install the new cam.

Just wanted to let everyone know to be leary of Cam Motion for hydraulic rollers.

tkm · 10-17-2002

Don't jump to conclusions so fast

Did you use new lifters and if yes were they FMS?

Did you use the proper valve springs with at least 135 lbs seat pressure?

Did you dial in the cam?

If no then don't blame Cam Motion

Cam motion is in the fastest cars on the planet

I use Cam Motion and have been since 1992 and never ever was disappointed in the results

I've built lots of Hyd Roller motors and they pull past 6000 and don't have anymore lift than your cam

What do your heads flow and at what lift?
How much does the intake cut flow when bolted on?
These answers alone can change your cam grind drastically

Not flaming you

just don't like when people blame stuff on others when the setup isn't correct so please don't take it in the wrong way

Just trying to help you sort it out

86Cobra · 10-17-2002

The answers to all of your questions are yes. I used valve springs from Cam Motion for this cam and new FMS lifters. I degreed the cam and it's fine.

You can stop rolling eyes at me. I'm not some rich chump who pays a shop to do everything. I do all my work myself. I'm not getting my answers from a shop. I've been fighting this problem for 3 months and refused to believe it was the cam until I had no choice. I guess I should have mentioned that at the beginning.

There are 2 reasons the power peaks at a low rpm - wrong intake and too wide an LSA. With the experience you claim to have, I'm sure you understand my point about the LSA. 111.5 is just too wide for a 306 cam that's supposed to support a 6600 rpm shift point.

Maybe with a better intake the LSA wouldn't be so much of an issue, but there is no excuse for it to float the valves at 6200 rpm.

I didn't say the cam was too small to pull past 6000. It's too small to reach my goal of 375+ rwhp.

I understand you being defensive of Cam Motion. I'm the same way about companies I have good luck with. Cam Motion had ALL of my info when they ground this cam. I'm not bad mouthing them I 'm just retracting my support I had voiced in earlier posts. I have buddies that run Cam Motion solid cams and they're awesome. Unfortunately, IMO, Cam Motion is not at the cutting edge of EFI hydraulic roller cams.

Twister · 10-17-2002

LSA? do you mean lobe centers? if so, that cam is designed for a speed density car, not a mass air car

86Cobra · 10-17-2002

LSA = lobe sep. angle. The cam has 4 degrees advance ground in so the ICL is 107.5.

Typical LSAs for street NA cams are 112 and 114 for blower cams.

86Cobra · 10-17-2002

Hey tkm, I'm sorry if I come across like a jerk in that previous post. I'm just really frustrated with this whole thing so please don't take it personally.

jjd975 · 10-18-2002

Do you plan to swap intakes first and see what it does with a new intake or are you just going to swap both? Would a ported TFS work and save you some cash? I would do an intake fix first and then look at the cam. Might have better info to use towards picking a cam if you go in that direction.

Good luck either way.

86Cobra · 10-18-2002

I'm going to go custom again on the cam but I'm not positive who yet. I'll have it ground for the Holley intake. I've discussed a ported Track Heat with TEA and they've had better luck with out of the box Holleys. I think I can get $300+ for my Track Heat so that'll take a chunck out of the cost of a Holley.

If it didn't float the valves just over 6000 rpm, I would just swap intakes and see what happens. But the valve float really tells me that they got the ramp rates wrong for a hydraulic roller.

Thanks for the luck. I'll take all I can get!

tkm · 10-21-2002

My Cam motion cams (hyd roller) have 112 LSA and 108 ICL

.557 in and .574 ex

Made 510hp 6100 and 460 tq at 4800 to the flywheel.

I just rechecked your specs and I don't think .5 of a degree will make a huge difference on your ICL and LSA

I think its the flow figures and intake restiction , and make sure you have 140lbs seat pressure.

What are your flow figures? email me if you wish.
tkmotion@qc.aibn.com

neQx · 10-23-2002

tkm knows alot

86Cobra · 10-23-2002

Quote:

Originally posted by tkm
I think its the flow figures and intake restiction , and make sure you have 140lbs seat pressure.

I don't understand how an intake restriction or head flow can cause valve float??

I'm not so upset with the hp number. I think a Holley intake would bring it up close to 360 but probably at around 6000 rpm. My problem is the valve float in the 6000-6400 rpm range. The springs are right so it has to be the lobe profile.

Head flow numbers:

Lift/intake/exhaust

.100 74.1 55.4
.200 136.4 107.2
.300 194.0 147.2
.400 246.1 183.0
.500 282.0 212.1
.550 298.7 225.0
.600 303.1 238.7

tkm · 10-25-2002

In another post you said it pulls hard til 6500 rpm

I think it was before your dyno test

Did you get the heads flowed or thats the figures that came with them from the shop that you bouight them from?

The reason I ask is those flow #s are real good and you should make more hp than that.
I know that its not the heads that cause the floating but could be the oil you use.(grade).
What oil pressure do you have hot at 6000 + rpms? and what grade oil ?

Did you check what seat pressure you had and if yes how?
Are you sure its valve float and not a limiter like the computer cutting out or a spark miss?stock computer limits out at 6200-6400rpm.

Sorry for all the ?? but trying to piece this together

86Cobra · 10-25-2002

Yeah, that's why I talked about my obvious inaccurate seat o' the pants meter. It felt ok to 6500 on the street in second gear but then on the dyno in fourth gear you could really feel the valve float and see it on the dyno curve. Spins a lot slower in fourth than second!

Those flow numbers are from the shop - Total Engine Airflow. Brian Tooley at TEA is known to be a wizard with TWs so I have no reason to doubt his flow numbers.

I'm using Mobil 10-40 normal dyno oil. Oil pressure stays at 70 psi all the way up. I watched the pressure on one of my dyno pulls.

I didn't check the spring pressure myself. I originally had weaker double springs in it that were 130 on the seat and 330 open. The springs Cam Motion sent me were supposed to be 140 and 380 at 1.8". I didn't check the pressure but I changed them myself and these springs are definitely stouter than the old ones. I'm very confident these are the right springs. I called Cam Motion back after I got them and double checked the part number.

I'm gonna be swapping on a Holley intake next weekend, so I'll pull a spring then and get it checked.

It's definitely valve float. I use a Tweecer to move the rev limiter. I originally had an EEC-Tuner but a couple of months ago I switched to a Tweecer for the data logging.

No problem on the questions. Thanks for the interest. I'm baffled too. I had buddies suggest valve float from the beginning and I refused to believe it until I had no choice.

tkm · 10-26-2002

Did you explain this to Cam Motion and if yes what did they say

Does the power drop off alot or slowly at 6000 rpm?
Did you check your dist and do you have a MSD?

Try 5w30 Mobil 1 oil sometimes the lifters don't like any oil thicker than 30 grade,
We've solved this simular problem this way once

86Cobra · 10-27-2002

I talked to Cam Motion when I got the new springs from them. They said it was definitely the weaker springs I had in there at the time.

It levels off from 5500 to 6000 then drops down and goes up and down from 6000 to 6500.

Before I realized it was valve float, I swapped out more parts than I can list trying to diagnose this. Fortunately I have a lot of extra crap in the garage and have buddies that let me borrow stuff.

I tried a different distributor and I bypassed my MSD. Changed coil, fuel pump, fuel filter, plugs, plug gap, wires, EEC, mass air meter, mass air wiring harness, and a bunch of other stuff I can't remember right now.

Hmm, I've spun to 6600 with other cams and heavier oil. Cam Motion didn't say anything about grade of oil. I understand how that might help but it shouldn't be necessary if the cam is right.