Need help designing custom camshaft, please

[Schmieder]

I'm sure there are a million threads on camshaft selection/design but I can't seem to get a straight answer for my personal application.

My biggest question is the effect of Intake Center Line. After browsing online I noticed two distinct vendors for 3x00 performance camshafts.

MMS seems to offer camshafts with an ICL around 106-108
While WOT-TECH seems to hang around an ICL of 111-113

What is the general difference between an ICL of 106 - 113? And how low or high can one go, reasonably, while retaining streetablility?

Next important question is what is the maximum safe lift I can go for with stock 3400 heads milled down 0.020"? Should I reduce the lobe lift by 0.020" from the maximum recommended lift? Reason is I want to increase compression w/o having to switch out pistons.

Can I effectively change the CR through camshaft design w/o hampering other aspects of performance?

This car is a daily driver, automatic trans, city driving 30-65mph but still want to push 80-90 mph easily. Low end torque is more important then high RPM HP.

So here is the basics,

1. No boost or NOS
2. Auto tranny
3. Urban driving
4. No headers atm but will build from weld kit later.
5. No tuning until I can get Megasquirt installed. Unfortunately I have the 96 Grand Prix ECU dilema.
6. Injectors, springs and pushrods will be matched to the camshaft.

Flow rates for the stock 3400 heads I will be installing

LIFT in inches - INTAKE CFM/ EXHAUST CFM
0.05" 32.6/27.1
0.20" 105.0/98.4
0.50" 224.1/157.0
0.60" 232.8/160.4

Any help or advice is greatly appreciated in my endeavor to squeeze every last drop of power possible from this 3100.


PS - I will be asking WOT-TECH to grind the cam when I finalize what I need and start purchasing parts.

[Schmieder]

Ok, so I learned something before a reply so I hope I got this right. Cause when I order and put it in, I really don't want to disappoint myself in bad cam selection.

I would prefer a few degrees advanced since I am leaning towards torque versus HP.

So an LSA of 114 and an ICL of 110 is basically showing a cam advance of 4 degrees?

And for torque I would want the duration to be shorter but not too short to restrict breathing.

It seems simple at first but when we consider spending good $$$ on a new ground cam it becomes are hard to choose issue, lol.

Lets see if this will work for a stock 3400 head with 0.020" milled off.

LIFT - 0.500/0.505
DUR @ 0.050 - 205/209
LSA - 110
ICL - 106

Would these specs be good for a strong torque cam in a 3100 w/ 3400 top end, 65mm TB, CAI and better flowing exhaust?


Or should I just go for the WOT torquer or street/strip cam?

What would be the best cam type for a modded 3100 Grand Prix?

I know I have a lot of questions and I really appreciate the help.

Thanks in advance!

[1988GTU]

Contact sappy (ben) pay him 30.00 (I heard it's refundable when you purchase one of his cams) and he can guide you into the best choice bump stick for your engine needs.

I don't want to be responsible for any flaws in picking your bumper thumper.

[robertisaar]

if you're unsure, don't drop cash for it.

talk to Ben directly and see about using the cam selection software(it's free if you buy a cam through WOT-Tech).

EDIT: ninja'd

[Schmieder]

Alright guys, that seems like a good idea contacting WOT. I have heard nothing but good about them. Unlike MMS where I am seeing many complaints.

I won't be purchasing until late January, tax season

It's not everyday when my wife agrees to me being able to spend upwards near $3,500.00 on my ride. I'm really excited putting this project together. That's why cam selection is really tough. Even deciding between stage I or II heads is tough. I'm sure stage I is nice, but then there is stage II

I think what really stumps me is whether to go more towards torque or HP. Either way is great. Having neck snapping acceleration or gut pulling top end. I can't make up my mind.

What would you guys suggest. Torque or RPM HP?

I guess higher RPM HP is probably logical since I am switching from small port/high velocity to larger port/more flow.

Especially with the addition of CAI and more free flowing exhaust.

[Schmieder]

if you're unsure, don't drop cash for it.

talk to Ben directly and see about using the cam selection software(it's free if you buy a cam through WOT-Tech).

EDIT: ninja'd

right. I am not spending a dime until I know exactly what i want/need as far as a cam is concerned.

What is your opinion for a 3100 with 3400 top swap, 65mm TB, CAI and opened exhaust.....low grunt torque or high rpm HP?

Shift points don't matter as of yet since I do plan on optimizing that once I get an aftermarket ECU.

[1988GTU]

There's a point where torque just isn't going to benefit you for daily driving. You'd be better off settling for hp and taking any torque that happens to develop in the process....

Go stage two.

[robertisaar]

if you go turbo, build the motor for low-RPM torque and the hairdryer will do all the pulling up top. best of both worlds.

[SappySE107]

There are general rules to motors, and then there are specifics to the motor you are working on. 106 ICL is good for larger duration cams to bring the powerband back down to realistic levels (but you need higher compression to make it better overall. I go for average hp in the powerband/redline range you will be operating with, and bias for low, high, or mid rpm power. This is based on compression and the weight of the vehicle as well as gearing, and all of it depends on the application. Daily driver, drag race, auto cross, etc

A 3100 grand prix for daily use, i would keep it in the 210-224 duration range and lift in the .550 range. That is the "dead center" I think, and obviously bias from there based on springs selection and longevity (and more).

The cam selection service is on the site to make this easier for both of us. I have to charge to keep those not serious from using my time (though obviously I am willing to help explain some of these things for free on this site). I want you to get exactly what you need, and I charge the same in the end if you get the cam from me as well.

[SappySE107]

These motors make plenty of torque, so going for more mid/top end is best if your transmission can take it. I love seeing these motors spin to 7000 RPM, but the transmission will appreciate a sub 6500 RPM peak.

[Schmieder]

There are general rules to motors, and then there are specifics to the motor you are working on. 106 ICL is good for larger duration cams to bring the powerband back down to realistic levels (but you need higher compression to make it better overall. I go for average hp in the powerband/redline range you will be operating with, and bias for low, high, or mid rpm power. This is based on compression and the weight of the vehicle as well as gearing, and all of it depends on the application. Daily driver, drag race, auto cross, etc

A 3100 grand prix for daily use, i would keep it in the 210-224 duration range and lift in the .550 range. That is the "dead center" I think, and obviously bias from there based on springs selection and longevity (and more).

The cam selection service is on the site to make this easier for both of us. I have to charge to keep those not serious from using my time (though obviously I am willing to help explain some of these things for free on this site). I want you to get exactly what you need, and I charge the same in the end if you get the cam from me as well.

Thanks. The way you helped explain ICL put it into better perspective.

In the end, I will be purchasing a cam from WOT-Tech among many other things so I will go through the cam selection service. That will be in late January.

The way I see it, taking my time investigating all options and resolving every question is the only way to go. I believe firmly in getting the job done right the first and only time around.

So I'm sure I'll be back with another question.

Thanks guys,

Merry Christmas

[Schmieder]

These motors make plenty of torque, so going for more mid/top end is best if your transmission can take it. I love seeing these motors spin to 7000 RPM, but the transmission will appreciate a sub 6500 RPM peak.

yeah, I'm not interested in burning up my tranny. Was rebuilt 3 yrs ago so it still has plenty of life left if I respect it well enough.

I'm sure I can get great performance up to 6.5k rpm max


Quick question. Going from stock motor to these mods > CAI, 3400 Street Heads, 3400 Competition intakes, performance cam (designed well), larger exhaust, larger injectors, stronger fuel pump w/ adj FPR and flowmaster 40's

Am I going to create more power then what my tranny can handle?

What kind of increases would I be looking at? roughly speaking.

[Beau]

I go for top end. How long are you going to stay in low rpms when you're racing? Its average horsepower, like someone said. But its average hp over TIME. You spend 1 second under 4k rpm in first gear, the rest is spent shredding through top end power. The longer you spend in your peak power band the faster you will be.

[SappySE107]

The transmission will take those mods if you keep it in the 6500 or less range. It would work for 7k if you wanted but just not as long.

Power depends on the cam and I have nothing to base power on for street heads since the dyno feedback has been street/strip. I don't know if you will need larger injectors or a fuel pump either (injectors maybe, pump probably not).

[robertisaar]

yeah, pump should be fine, assuming it's healthy. injectors is something that will need to be seen after it's all said and done...