408 build

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Lift has a direct impact on HP. Not so much torque. The idea of lifting the valve high is to take advantage of the heads high flowing capabilities. If it has them.

Duration is where the rpm band is determined and yes a smaller cam lowers the rpm band in which it operates in. You have to be careful because a small cam has the timing events closer together and this can cause cylinder pressure to sky rocket. Thus making pump gas impossible to run.

Most cam manufacturers will list an operating rpm range where the cam should perform in. Crane goes as far as to even list the cruise rpm band in which there cam will perform in.

Most other companies will list the cams power band range. Hughesengines has a listing in there tech pages on where a cam should be making power T a min and max if you follow there suggested parts to work with the cam being used.

Without getting into cam talk, because it can get deep quick & be a little confusing, just follow the suggested parts list that the cam works with best. Cam manufacturers can play with the cams timing and ramps to come up with some pretty slick results. Unless you understand this kind of stuff, I suggest the K.I.S.S. Method.
(That would be, Keep It Super Simple)

Otherwise, you’ll end up on the phone with Comp or Crane or ..... talking about everything and then some more about the whole deal for the cam. They will want to know EVERYTHING about the whole deal. So be prepared to have every little detail about your car, trans, rear gear and tires & and wht you want to do or expect from it.

If your well prepped and spend the time on the phone, chance is, your going to be REAL happy with the custom grind your going to get.


Thanks Rumblefish, i do have a basic idea of how it works, where i get confused one cam might be referred to as street-able while another cam with what appears to be only slightly more lift and duration might be referred to as un-street-able, I just wondered how that is determined without testing in a given engine.. I've also been told that a stroker will tolerate a bigger cam than a non-stroker in the street-able category. Anyhow i don't want to highjack the OP's thread with cam talk and thank you for your response.
 
"streetable" is a highly subjective and unmeasureable term. Even if you test a cam, my/your version of 'streetable' is not someone else's... and tuning and setup enters into it a lot. Really hard to answer that question.... Notice that I am not trying to for the OP LOL
 
@A408Cuda

Sorry if I went over known info with you. It was (at least from my point of view) information given generically for those not knowing.

However, I can look at most cam specs and determine if there going to work the way the op wants or expects. That in itself is pretty broad and general in terms.

But! The cams timing events, the way the profile is cut and where the timing events happen in relation to the engine and the other lobe have a huge effect on everything. I have spent a generous amount of time learning camshafts (NOT AN EXPERT, but I get it) and I just want to say it is best to keep it simple unless your looking for every last HP or MPG from the combo. It does get confusing.

Match the duration to the cruise rpm and have the drivetrain compliment it, your good to go.
 
No sorry necessary, the knowledge found from people on this site is priceless, and seriously no joke i would love to be able to look at a cam and know what its going to run like, someday maybe but not there yet.:thankyou:
 
No sorry necessary, the knowledge found from people on this site is priceless, and seriously no joke i would love to be able to look at a cam and know what its going to run like, someday maybe but not there yet.:thankyou:[/QUOTE
Usually best to contact a cam manufacturer on what your intent and goal and go from there I had Hughes recommend my cam after talking about my combination and has worked good for me car runs real good and hope to get some track time to see how much I improved.There is a lot of knowledge on this site and makes choices a little easier.
 
I’m having a hard time imagining how that conversation went, where after the “street car”(closed exhaust), and 3.23’s were mentioned........ how they ended up recommending that cam......on a 106.
 
Comes out at 10.8 SCR so that part agrees with the earlier data.

Is the 186 psi cranking pressure computed or measured?

You do have a decent quench gap with that setup; that is good.

The 186psi cylinder pressure is only calculated as nothing been assembled yet
 
This is my Cam specs (1.5 ratio Crane gold rollers). My engine is a 418 (340 based .040 over) 10.5 :1 compression that dynoed at 490 horsepower and 516 torque. My car has manual steering and brakes so there is no extra load on the engine. My converter is a 3500 stall TCI and I am running 355 gears. It is a handful on the street especially if you are not running drag radials, BFGs are NIT gonna cut it. I just got 255/60/15 MT SS tires (the biggest you can put in a stock wheel well with the llips rolled). The idle is rough (but I like it) and like others have said it idles at about 750 RPMs.

Cam_Card.jpg


 
Hey MO. What would you consider to be 'better exhaust valves', and what is the particular reason to change them under these circumstances?

Boarder line octane and lean conditions at the top of the range, at your shift points, you can warp those run of the mill stainless exhaust valves in no time. When you first get it going you start out with your carb's out of the box Baseline ...unless you'd already had the combo going before and tuned it from there. You fiddle with the power-valve rating ,Shooters , primary ...secondary...generally we usually leave the secondary alone and do most of the work in the primary but once you start getting into high flowing heads High cylinder pressure and big RPM aaaaand you're using a smaller Street carb ....say a 750, you'll find that you are increasing the secondary Jets eventually with the increased volumetric efficiency with all those 'upgrades'.
More power, more heat, touchier on available octane...things happen.
 
Would a smaller cam make it more street-able? If so how do you determine the cam size, I've often been confused about the real difference between say the OP's .573 and .590 and say .566 and .583 does it really make that much difference? seems like such a small change.
Where to look is at duration, that is what makes a difference
 
Would a smaller cam make it more street-able? If so how do you determine the cam size, I've often been confused about the real difference between say the OP's .573 and .590 and say .566 and .583 does it really make that much difference? seems like such a small change.
Lift being equal, you will feel a difference down in the, but, correct, it won't be a big difference for that amount of change.

IMHO, you start with application and knowledge (experience, that you learn your self or from others). If 'more streetable' is desired, then you move to improve lower- and mid-range torque, and that typically drives to lower durations and cam timing changes (more advanced cam timing) to get the intake to close earlier to help build cylinder pressure higher. With some level of static compression ratio, both work to move the dynamic compression ratio number (DCR) up. That has a direct impact on low to mid RPM torque, but less so on high RPM power. LSA changes (usually a wider LSA) are made to make the very low RPM operations smoother (idle, off-idle).
 
This is my Cam specs (1.5 ratio Crane gold rollers). My engine is a 418 (340 based .040 over) 10.5 :1 compression that dynoed at 490 horsepower and 516 torque. My car has manual steering and brakes so there is no extra load on the engine. My converter is a 3500 stall TCI and I am running 355 gears. It is a handful on the street especially if you are not running drag radials, BFGs are NIT gonna cut it. I just got 255/60/15 MT SS tires (the biggest you can put in a stock wheel well with the llips rolled). The idle is rough (but I like it) and like others have said it idles at about 750 RPMs.

View attachment 1715308895


your car sounds nice!
 
This is my Cam specs (1.5 ratio Crane gold rollers). My engine is a 418 (340 based .040 over) 10.5 :1 compression that dynoed at 490 horsepower and 516 torque. My car has manual steering and brakes so there is no extra load on the engine. My converter is a 3500 stall TCI and I am running 355 gears. It is a handful on the street especially if you are not running drag radials, BFGs are NIT gonna cut it. I just got 255/60/15 MT SS tires (the biggest you can put in a stock wheel well with the llips rolled). The idle is rough (but I like it) and like others have said it idles at about 750 RPMs.

View attachment 1715308895


But what heads are you using?
 
My 408 also uses a Hughes custom cam, and also uses a 106 LSA, and is also a hot street car. In my case the 106 LSA was spec'd to fool engine into thinking it had more than its 10:1 compression at my elevation of 3200 feet. This is in a 69 Swinger with a 4 speed. 3.55 gears only provide rubber at anytime up to 60mph with street tires. The 2.94 gears are actually a lot of fun on highway trips, still a major traction issue in 1st and second gear. I can let clutch completely out in 1st without any throttle input. Current intake is Victor W2, this season I am going to experiment with a dual plane W2 intake for fun. I have 4.10, 3.55, 2.94, and 3.23 chunks to swap around, only one I havent tried is the 3.23 which I feel will be just the ticket for fun all around driving, my 3.09 first gear a833 trans helps with not needing deeper rear gears. Here is my cam, engine made 547 hp, 562 ft/lbs.
20151223_094123.jpg
 
My 408 also uses a Hughes custom cam, and also uses a 106 LSA, and is also a hot street car. In my case the 106 LSA was spec'd to fool engine into thinking it had more than its 10:1 compression at my elevation of 3200 feet. This is in a 69 Swinger with a 4 speed. 3.55 gears only provide rubber at anytime up to 60mph with street tires. The 2.94 gears are actually a lot of fun on highway trips, still a major traction issue in 1st and second gear. I can let clutch completely out in 1st without any throttle input. Current intake is Victor W2, this season I am going to experiment with a dual plane W2 intake for fun. I have 4.10, 3.55, 2.94, and 3.23 chunks to swap around, only one I havent tried is the 3.23 which I feel will be just the ticket for fun all around driving, my 3.09 first gear a833 trans helps with not needing deeper rear gears. Here is my cam, engine made 547 hp, 562 ft/lbs.View attachment 1715309703
Now THAT is stout! I'm thoroughly impressed.
 
I run this cam in mine. 10.5-1 with pro comp heads. 2.05/1.88 valves with minor port work with 1.6 rockers. Air gap intake with Holley sniper. 3.91 gears, tires are 235/40R18 (25.4 tall) 727 transmission 3500 converter. Supposed to be 500ish hp 500+ torque. Streetable to me... idles @950 or it will shake your teeth out, melts the tires at will in 1st or 2nd gear, freeway sucks, 65 mph @ 3300 rpm gets old. Best for cruising below 50 mph or 0 to 120 mph. Thinking of going 3.23 this year.

32B774B0-B1AD-4C03-97FB-8240B30F3B38.jpeg
 
I run this cam in mine. 10.5-1 with pro comp heads. 2.05/1.88 valves with minor port work with 1.6 rockers. Air gap intake with Holley sniper. 3.91 gears, tires are 235/40R18 (25.4 tall) 727 transmission 3500 converter. Supposed to be 500ish hp 500+ torque. Streetable to me... idles @950 or it will shake your teeth out, melts the tires at will in 1st or 2nd gear, freeway sucks, 65 mph @ 3300 rpm gets old. Best for cruising below 50 mph or 0 to 120 mph. Thinking of going 3.23 this year.

View attachment 1715309780
Curious if you ever ran it with a carb, or only the sniper? I'm considering getting a sniper kit for mine, I'd like to know any driveability improvements.
 
Curious if you ever ran it with a carb, or only the sniper? I'm considering getting a sniper kit for mine, I'd like to know any driveability improvements.
No. Only the sniper. I’ve read a few things people posted on various sites and most did not see a big performance difference on the track. In town though, hot ,cold or whatever it’s been pretty flawless. Ran a 340 with a carb that was pretty dialed in and this is much more consistent.
 
No. Only the sniper. I’ve read a few things people posted on various sites and most did not see a big performance difference on the track. In town though, hot ,cold or whatever it’s been pretty flawless. Ran a 340 with a carb that was pretty dialed in and this is much more consistent.
Thanks
 
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