Cam selections...

[Turbo6Smackdown]

My engine builder just got a 206/210 from DLS as well. When this car get's broken in this spring, (i hope that's broken IN, not broken lol) We'll see what this cam does. I made this thread specifically, to get stickied, so that we don't have to mess about any more, picking and choosing. Sort of like the new turbo chart.
Maybe I could get a few tech guys from comp, melling, or whoever, to come in here and lay down a little "why's" or "how comes" , in the technical aspects... In fact, Ill make the call tomorrow.

 

[V6gofast]

My engine builder just got a 206/210 from DLS as well.



I am sorry to tell you but I don't sell a 206/210, 99% of my cams are single pattern so either you are misinformed or mislead.

 

[Pronto]

 

[JP112_89]

..

Like I said I am going to try the 212/212, hey if it works great if it doesnt o well thats the fun of it.

I would just call Dan at DLS. I could not be happier with his selection for my combination.

FYI, a 210/210 cam has been in the 9's. Don't over cam your car dude. It's not "fun".

 

[Turbo6Smackdown]

hmmmm. Stand by...

 

[hensleyt]

dont stop now

I have searched every cam thread and I have got three of many cam selection questions out of the way.1. Roller good but out of my budget.2.Flat tappet OK add ZDDP,3. 206/206. My #4. What L/S and installed L/S??I have selected 206 flat tappet because of help from the board and I'm CHEEP.My gollies have changed from last year from high 12's to mid 11's .10's are out ,I'm not installing a roll bar.The stock cam is 107 L/S and can go in the 11's with some high boost and spray ,Comp 206 is 110 installs 106 Ta is 112 Isky 112 and 114. But what L/S and installed L/S would work best with my combo?All the cam manufacturers will custom grind 205-207 lobe on a Buick stick for a fear price.The engine is coming out to fix the oil leaks and install a set of fresh home ported heads.I have a PT 5857 BW BB ported S cover(605 hp),3 in down pipe and test pipe, Cold air ,15 row SLIC,hot-wire ,regulator,Extreme auto trans, Edge 2500 9.5 LU,UMI uppers and lowers,255-60 MTDR. I now there is no magic chart for cams like Patricks turbo chart ,But how do these car react to L/S ,Advance are retard L/S

 

[Jerryl]

IMHO, there is some good cam info in this thread from the experts.
http://www.turbobuick.com/forums/turbos-turbo-related-parts/144094-boost-vs-back-pressure-3.html

Some of the added questions with the generic cam question, is that we rarely know the CL, LSA, and Lift, combined with the timing at 0.XXX", for a specific purpose Track/DD/Boost) and combo (Heads, turbo, etc), combined with the weight and drive train info.
The combination of ALL those are the secrets.

A 206/206 cam "can" be the wrong cam, if you decide to go 9's.
Sure, that cam has gone 9's, but we will never know all the specs, and if the cam was advanced or retarded to make it work on that specific combo.
That same cam may not work very well on another combo (News flash right? LOL)
IMHO, Boosted engines are not real super sensitive to cams, but are more sensitive to the combination and very sensitive to the final tune.

In my little mind, the cam is one of the final selected parts, unless the other parts are known, i.e;
Head flow balance, turbo size, gas used, CR, gearing, tires, purpose, operating parameters, etc.

You can talk to 3 of the best engine builders, and possibly get 3 different answers on the cam.
Case and point;
As long as racing is competitive, and people are out to set records and win, it will be part of the "trial and error mystery", aka, "Paying the price".
What you pay for, when buying a cam from some of the big boys, is not just hardware and service, but kowledge.
Pick a known engine builder and stick with them, ALL the way through the build, and whatever cam they suggest, you won't be dissapointed, IF, you can get the tune right.

 

[quickt]

My engine builder just got a 206/210 from DLS as well.



I am sorry to tell you but I don't sell a 206/210, 99% of my cams are single pattern so either you are misinformed or mislead.

Hi Dan,
Tony is the owner of the 210 kit I received this week. We spoke about the change to the 206/210. Sorry I did not bring him up to speed. Told him to call you if he had any questions.

 

[imjoesnuffy]

At what point does a cam become non street friendly? 218/218....224/224....234/234....or higher?

Will going to a higher rocker arm ratio from the stockers make a difference, without changing shift points?

Currently running a 206/206 hydraulic roller, ported 8445s and have trapped as high as 127 in the 1/4. I am just wondering if this cam is holding me back, car shifts at 5900 rpm with a 3500 stall.

Didn't want to start a new thread since this one has alot of good info.

 

[sweetv6]

some interesting information at page 6

http://www.grapeaperacing.com/tech/turbochargers.pdf

claude

 

[87WE4BOOSTED]

some interesting information at page 6

http://www.grapeaperacing.com/tech/turbochargers.pdf

claude

Thanks for sharing. Some really good info there. :biggrin: I still have to re-read it to let all that info sink in. :biggrin:

 

[Jerryl]

some interesting information at page 6

http://www.grapeaperacing.com/tech/turbochargers.pdf

claude

Claude,
Good link!

A few of my observations;
“You want the intake valve to open as soon as possible. In an ideal situation, the intake valve should open when the pressure in the cylinder is equal to boost pressure.”
“Using 0.050” lift figures, this means that the intake valve needs to open 20-35° ATDC, depending on the amount of boost you're using. Most street turbo's will work well when the valve opens close to 20° ATDC, only when boost gets near 30 psi will you need to delay it as much as 35° ATDC.”

While those are true statements, the listed degrees “20-35” depends on the bore / stroke/rod length, and CR. If the numbers were true for our cars, most of our cars would not run the way they do. If you run the calcs, you can clearly see that.

 

[charlief1]

Great link and I saved the PDF for later.:biggrin:

 

[Alky V6]

It seems most are concerned with small street/strip cams, but let me just throw in my cam ideas to stir the pot. This will be more for the racers out there.

Intake duration is going to dictate where the power band will be in the rpm range of the engine. More intake duration, more rpm, and the higher the power band will be in that rpm range. If one is not prepared to go through the other planning that will be necessary to make an engine live at a higher rpm, then ignore this post and stick with the small cams. But, you may still want to read on to learn some of the not so attractive traits of running a small cam with big boost numbers.

IMO I think it's safer to go fast with more rpm in the mix. If you limit your rpm with a small cam and are trying to go fast with it, you're forcing a lot of cylinder pressure on the motor. A larger cam will lessen cylinder pressures in the mid-range with some sacrifice of power in that range, but with the gain of rpm you will end up with more power with safer cylinder pressures throughout the whole rpm band. It is a trade off, but who likes changing head gaskets all the time.
As long as you understand where your cylinder pressure limit (boost limit) for your setup is, with the cam you're using, and you're happy with the limits put on you by the camshaft (ET wise), then you'll be fine. Most will push the limit, though, and we'll be looking at the next discussion of making head gaskets live, and making another sticky out of that one.

Making a boosted car fast with limited duration and rpm will strictly be done by pushing the limits of cylinder pressures. Period. Adding hardware to increase the rpm limit of the engine, and thereby allowing a larger cam to be used will help lessen cylinder pressures throughout the rpm range, particularly at peak torque rpm where cylinder pressures are typically the highest.

Some will then complain that you need larger heads to take advantage of a larger camshaft. That is not necessarily true. If cam specs are properly matched to even a small set of heads, great numbers can be had. Such as in my case. I'm probably running even smaller heads than most of you street guys with aluminum heads right now. Yet, due to my camshaft being able to make up for the lackings of my heads, I'm doing 8s with only 30 lbs. of boost. And, with a very safe cylinder pressure number.
I hate changing head gaskets.