[CobraMarty]

So to add 1.0mm more valve lift would require cam base circle to be 0.6mm smaller. You can't make the peak higher but you can make the base smaller.

So base would have to be at least 29.4mm or smaller. Which would give a max valve lift of 10.7mm.

[hassmaschine]

The interesting thing is I don't think you can easily change the 'duration' - at least not without knowing what the affects of the variable rocker ratio are. The lobe shape of the N52 cam is way different from a standard cam - it's almost a perfect circle instead of the usual egg shape. From what it looked like of pete's cams, I'm not sure they understood the difference (but I actually don't remember what it looked like anymore).

The other question is if you can make up the base circle change with the hydraulic lifters. Or just swap them out for fixed lifters/shims..

[justpete]

Originally Posted by CobraMarty

I measured the stock cam as best as I could with HF digital mic.
Base looks about 30.0mm and peak lobe 35.90mm
For cam lift of 5.9mm.
9.7 l 5.9 = 1.644:1 max rocker ratio.

Yeah, that sounds like what I measured as well, the ratio looks familiar. Whether it's the actual ratio throughout the eccentric travel is unknown, this is only the endpoint.

[CobraMarty]

Originally Posted by hassmaschine

The other question is if you can make up the base circle change with the hydraulic lifters. Or just swap them out for fixed lifters/shims..

I didn't bring it up yet but that is what I was thinking also.
I have to look up how much travel the hydraulic lifters have and how much preload is placed on them. If lifter preload is less than 0.6mm, you might have a terrible 'ticking' sound.

Having to change lifters to fixed or use shims under the hydraulic lifters really increased the work.

So many questions.

[hassmaschine]

I actually think you could just stick a small shim under the stock lifters and that would work fine. IIRC, the oil hole comes from the side (although it would be trivial to drill a hole in the shim if required).

A shim would be a pretty simple part really - just a flat, round disk. If you used it with stock lifters it wouldn't even have to be perfect, since any variation would be taken out by the lifter anyway.

[justpete]

Originally Posted by CobraMarty

I didn't bring it up yet but that is what I was thinking also.
I have to look up how much travel the hydraulic lifters have and how much preload is placed on them. If lifter preload is less than 0.6mm, you might have a terrible 'ticking' sound.

Having to change lifters to fixed or use shims under the hydraulic lifters really increased the work.

So many questions.

I ran these regrinds for a few months, iirc, and ran a bunch of dynos and there was never any ticking or other odd sounds I or the race techs noticed.

[CobraMarty]

Didn't realize that you had these installed, running and dyno'ed.

[justpete]

Originally Posted by CobraMarty

Didn't realize that you had these installed, running and dyno'ed.

Detailed here or in a cams thread on 1addicts, don't remember right offhand.

[CobraMarty]

I just went back and read those 'cam' threads. I even posted in them. I guess when they were a 'fail' I mentally 'deleted' the info from my head. Or I'm just getting old.

The numbers I did back then are similar to what I got today.
Before- 1.182" base and 1.427" nose, = 0.245" cam lift = 6.224mm cam lift
Tonight- 30.0mm (1.181") base and 35.9mm (1.4134") nose, = 5.9mm cam lift ( 0.232").

So now a couple years later you are sending the cams off to BPC for them to try and see if they can get them to work with their tuning abilities.
Now I got the story.

Before I installed them in anything, I would have them checked on a 'Cam Doctor' and check them against a stock cam. Maybe RR just polished the lobes and made them very pretty. That's why they didn't make any more power. I hope it wasn't like- take out the stock cam and replace it with a different 'shinny' cam.

I would want to know exactly what I have and not what I was told that I have.

[justpete]

Originally Posted by CobraMarty

I just went back and read those 'cam' threads. I even posted in them. I guess when they were a 'fail' I mentally 'deleted' the info from my head. Or I'm just getting old.

The numbers I did back then are similar to what I got today.
Before- 1.182" base and 1.427" nose, = 0.245" cam lift = 6.224mm cam lift
Tonight- 30.0mm (1.181") base and 35.9mm (1.4134") nose, = 5.9mm cam lift ( 0.232").

So now a couple years later you are sending the cams off to BPC for them to try and see if they can get them to work with their tuning abilities.
Now I got the story.

Before I installed them in anything, I would have them checked on a 'Cam Doctor' and check them against a stock cam. Maybe RR just polished the lobes and made them very pretty. That's why they didn't make any more power. I hope it wasn't like- take out the stock cam and replace it with a different 'shinny' cam.

I would want to know exactly what I have and not what I was told that I have.

RR used cam design software to develop the regrind profile, they're quite different from stock given the dimensions on the cam card I have, somewhere. There was no way the DME was going to adapt, it'll take a tune to do something with them, if at all. Interesting experiments. Well, to me anyway.

[CobraMarty]

No more power when tested before. And now do it again expecting different results. Oh wait, the magic is in the tuning. Isn't there a saying about doing that somewhere.

I hate to point fingers at anyone but to be honest, I would call RR BS until proven otherwise. 'used cam design software, to develop the regrind profile, they're quite different from stock, given the dimensions on the cam card, I have, somewhere". That reads like BS, BS, BS, BS, here's your 'shinny' cams.
Hello, Valvetronic, Vanos. And the possibility that the intake profile was ground on the exhaust cam and vise versa. What a load of rubbish.

All the more reason I would have BPC take the cams to a shop with a Cam Doctor tool and measure the cams exactly so you and the tuner knows exactly what you are dealing with. Anything else is just poking blindly at a moving target.

$100 on ebay for the service=
https://www.ebay.com/itm/Audie-Techn...-/111722157556
But I am sure in NC, in NASCAR land, there is a shop which can do the 'Cam Doctor' service for you.

The only cams that I would trust to be done correctly are the stock factory cams. All others need to be checked by third party especially when they don't make any more power or shift the power curve.

Just saying.

[CobraMarty]

On another note, I do like the ATI dampner. Did it make a difference? I think I want one if it made a difference. Maybe need to call VAC. Any idea price?

[justpete]

Originally Posted by CobraMarty

I just went back and read those 'cam' threads. I even posted in them. I guess when they were a 'fail' I mentally 'deleted' the info from my head. Or I'm just getting old.

The numbers I did back then are similar to what I got today.
Before- 1.182" base and 1.427" nose, = 0.245" cam lift = 6.224mm cam lift
Tonight- 30.0mm (1.181") base and 35.9mm (1.4134") nose, = 5.9mm cam lift ( 0.232").

So now a couple years later you are sending the cams off to BPC for them to try and see if they can get them to work with their tuning abilities.
Now I got the story.

Before I installed them in anything, I would have them checked on a 'Cam Doctor' and check them against a stock cam. Maybe RR just polished the lobes and made them very pretty. That's why they didn't make any more power. I hope it wasn't like- take out the stock cam and replace it with a different 'shinny' cam.

I would want to know exactly what I have and not what I was told that I have.

I should say that the other half of the equation, head flow optimization, is worth investigating next and I'm in the process of it now. Worse come to worse will be having someone like Lang Racing develop a race engine with custom cams, no Valvetronic, and the head machined to use N54 VANOS units, intake cam tray, and timing chain, etc. Will require moving to a Motec controller and modifying the TB for mechanical operation. May as well have custom pistons for higher static CR at the same time.

Got the master cylinder piston diameter info back from Tilton yesterday but whether it's two or three pedals will depend on the regrind results.

[justpete]

Originally Posted by CobraMarty

On another note, I do like the ATI dampner. Did it make a difference? I think I want one if it made a difference. Maybe need to call VAC. Any idea price?

Completely eliminated low frequency vibration.

[justpete]

Originally Posted by CobraMarty

No more power when tested before. And now do it again expecting different results. Oh wait, the magic is in the tuning. Isn't there a saying about doing that somewhere.

I hate to point fingers at anyone but to be honest, I would call RR BS until proven otherwise. 'used cam design software, to develop the regrind profile, they're quite different from stock, given the dimensions on the cam card, I have, somewhere". That reads like BS, BS, BS, BS, here's your 'shinny' cams.
Hello, Valvetronic, Vanos. And the possibility that the intake profile was ground on the exhaust cam and vise versa. What a load of rubbish.

All the more reason I would have BPC take the cams to a shop with a Cam Doctor tool and measure the cams exactly so you and the tuner knows exactly what you are dealing with. Anything else is just poking blindly at a moving target.

$100 on ebay for the service=
https://www.ebay.com/itm/Audie-Techn...-/111722157556
But I am sure in NC, in NASCAR land, there is a shop which can do the 'Cam Doctor' service for you.

The only cams that I would trust to be done correctly are the stock factory cams. All others need to be checked by third party especially when they don't make any more power or shift the power curve.

Just saying.

Whatever. You're welcome to your opinion but please realize it's worth nothing to me, I really don't care.

Hmm, maybe you don't understand that the costs involved are trivial to me so experimenting about is actually fun. Twenty grand for a race engine for example wouldn't really be noticed. So ya know I don't take this seriously.

[CobraMarty]

Not saying anything about costs or deep pockets. Just ask the right questions.

It will be interesting to see where this really goes.

[justpete]

Front brake cooling going in. Modified M235iR outlets at the rotors attached to the knuckles are in and the modified F30 dust shields are discarded (this is all there is now), frame rail boxes being fabricated, duct hose from the M235iR is being used, and the inlets are at the scoops built into the BMW Aero bumper.

[justpete]

Got the 6" Burns muffler/resonator installed in place of the merge and reused PE dual tips. Now with a turn down tip, am told it's a lot quieter. The 4" Burns muffler is still in place, no other changes.

[W37V]

Damn, you car is coming along really nicely.

Any updates on cams?

[justpete]

Originally Posted by W37V

Damn, you car is coming along really nicely.

Any updates on cams?

Also got the Longacre roll bar mount mirror brackets ordered from Summit this morning and i'd requested they fab a footrest for the passenger and that's been accepted to the to-do list at the shop. Not sure if the floorboards have been fabricated yet though. Not much left to do this time around.

Looking at head work and ITBs thanks to Hass and Wide Open Throttle Technologies. The race team provided the contact for the race engine shop that's built for them over the years, Kim Barr Racing Engines in Garland, TX. Will get into that once the top end is optimzed, if possible.

Not expecting anything on the cams for a few weeks or so.

[3002 tii]

Will this be ready for 2018? If so have you decided where you'll be competing?

[CobraMarty]

Originally Posted by justpete

Looking at head work and ITBs thanks to Hass and Wide Open Throttle Technologies.

Head/intake to ITB adapter plate?