Billiumss

iTrader: (11)

Has anyone ever done or heard of having a combo like this?

The reason I'm asking is for 3 reasons:

1 - Somewhat stealth, a little lope because of the big cubes and 240+ duration

2 - Reduction of exhaust smell at idle and low rpms

3 - More driver/street/tuning friendly

By having a higher LSA on a stroker, will I kill any top end power or not?

I really don't drag race too much maybe once, twice a year for a total of 20 passes. My car is more a street crusing car than anything, going to car shows and such.

ArcticFormula

Surprised you dropped the cash on a stoker without a cam choice in mind, nonetheless, You don't have many choices of 118 LSA variety unless custom. I would say the Steath II, that is what I'm looking at and I have about 6K+ less invested than you. Are you really serious or just yanking our chain here.

someday

i would try something like a 234 on a 116 or 117 and the higher lsa will keep the power up top, not kill it

Demon SS

iTrader: (3)

Billiumss- give me a call or shoot me your number, I'll be glad to help you with some thoughts on a cam for that setup. a 240ish duration with a little bit of split on a 116 or a 118 should work well for your needs. what heads are you going with?

J-Rod

LSA should be the byproduct of the valve events you (or your cam designer) selects. Many cam companies talk about the LSA as if it is an adjustable feature. They will usually spec a wide LSA for street use and a tighter one for race use. The justification is that the wider LSA gives a better idle. The real truth here is that the LSA for optimum results, within a specified power band, for a given engine, is not adjustable. Only one LSA will produce optimal torque and power for a given engine spec and powerband. Any time it is suggested that the LSA be spread to improve idle quality it is a sure sign that the duration chosen is too long for the job! Sure a wider LSA will spread the powerband and improve the idle, but the price paid for spreading the LSA to achieve a certain idle quality is a substantial reduction in torque and power.

It is little known outside the cam industry that cam grinders often deliberately spread the LSA to protect overzealous hot rodders from the negative effects of an excessively long duration cam they insist on wanting to install.

Although the LSA is an important entity, its determination alone is still not enough to allow an optimally specced cam to be produced. In actuality it is more part of the answer rather than part of the question.

2 SLOW

and i have heard a 114 LSA cam in a 422 and it sounds stock

Billiumss

iTrader: (11)

I haven't bought/built any stroker yet, just asking some questions. I have the block now and probably will be buying all the parts this fall for a winter project.

Like I stated above, I would like a little lope, but a little more than stock, Reduction of exhaust smell at idle and low rpms, & More driver/street/tuning friendly.

As for heads, I currently have Absolute Speed Stg 2 241 heads. Not sure if I'm going to have Jay rework them or just buy new ones from him. I was thinking going the LQ9 route on heads.

My HP & TQ goals through a M6 and stock rear end is 510hp & 490+TQ at the wheels. Stock rear end will be replaced with a 12 bolt at a later date.

I want to have a CR of 11:1, I run 93 Octane all the time.

So what spec of cam would you guys recommend for all of my goals? I really don't drag race much, I just want to say I have 500+ at the wheels N/A, dyno queen, maybe...

Bill

CHRISPY

I probably wouldnt go 240 on a 118LSA.

Something in the 236/240 on a 116 would work very well.

Billiumss

iTrader: (11)

Chris,

Will that get me to 500+HP?

So what is the proper way to figure out the best cam for a certain engine?

If you know the flow numbers of the heads, Bore & Stroke, and the headers diameter, can you use that info to figure out cam specs? I know alot of people have tried and trued cams over the years, but what is the proper way to spec a cam to an engine? There has to be more than just a good guess...

Ever since Vince posted his dyno graph of his 408CI, I shouldn't have any problem getting at least 500+HP at the wheels, I'm sure he inspired more than just me!!!

CHRISPY

Look at valve timing to get it where you want. There are spreadsheets you can use for this.

Take into account:
head config (valve size, port volumes, flow numbers, compression)
What gas you are using (octane)
intake limitations
headers (primary size, primary tube length, collector type and rest of exhaust. Whether there are cats etc)
Projected power output and gearing/converter choice
Use of the car (street/strip, drag only, autoX etc)
weight of vehicle

and on and on it goes...

If you are running full exhaust or cats I would lean more to a slight traditional split.

DAPSUPRSLO

iTrader: (14)

Isn't this quoted from the article in GMHTP. Regardless, I agree with this whole heartedly.

You will be leaving power on the table with a cam like this (116-118lsa). This motor will not be getting the overlap it needs to make its best power. It will make good power because of its size but not what it could.

With a cam with that wide of an lsa you need to really focus on the heads to get to your required number, especially in the extreme low lift areas to make up for the lack of simultaneous opening of the exhaust and intake valves for the scavenging effect. Remember, without power adders scavenging is where you make added power. Good luck.

J-Rod

IT probably is. I have been pulling bits and pieces out of the cam threads to make a more digestable 1 or 2 page "General Cam Document". It was in there, I had cited that article, so that may be where it came from (I'll have to go look). Anyhow, you don't have to have a stinky exhaust or a car that won't idle.
You can have a car with some lope to it.
A properly spec'd out cam won't surge and buck, and a tuner should be able to tune it for you with no more issues that any other cam.
Cats on the car will cut smell much more than specs in most cases...

A big motor (422) will also eat up a cam that would be considered "big" on a 346.

Cstraub

iTrader: (1)

With 400 + inches you should not have that much problem hitting your goals. Based on the induction system and rpm range you want power, something in the 230 range should be just fine.

Chris

necrocannibal

iTrader: (5)

You wont hit 500 rwhp with those heads. I just had a 408 built and put Stage 2 Absolute heads on it with a bigger cam (234/242 .598/.610 114+4) and I only put down 440 rwhp and 450 rwtq. I am trying to switch heads now but the motor has drained my account so I am broke now.

2000 Tran Zam

iTrader: (2)

I had read his post as well, and am now in the process of building the same motor with FMS, but i will have AFR heads, a step above ls6 heads. im hoping na, with the same 243/250 cam and my setup i should dyno close to 570 through stock 10 bolt with 3 42's and 530-550 with the strange 12 bolt and 4 11's. im having the car shipped over there to have them pull the motor, install and tune it it should be nice when its done 2 months from now.

Billiumss

iTrader: (11)

Hey J-Rod, what kind of cam would meet my requirements? How do you figure it out?

Ed Curtis

That's what you pay your cam designer for....

Ed

Billiumss

iTrader: (11)

Ed,

What, just call up CompCams and tell them my goals and they'll know? Almost sounds to easy...

Bill

CHRISPY

Yep!! This is contingent on a great flowing set of heads with PROPER port volume for the displacement.

necrocannibal

iTrader: (5)

Agreed. My heads are killing my 408, bad. I should be around 500 rwhp if not over but only put down 440 because my heads suck, atleast for this motor.