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400sbc camshaft?

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by Heavymetal, Apr 5, 2002.

  1. Heavymetal

    Heavymetal 1/2 ton status Premium Member

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    I am thinking about getting an Edelbrock cam and lifters for my small block 400. It is basically a stock rebuild with K&N air filter, edelbrock performer intake, and hedman torque step headers. I am looking for low end power. According to edelbrock their cam with my engine should produce about 390 ft/lbs of torque between 2500 and 3500. Does anybody know of a better cam for my application and low end power?

    Thanks,
    Mike.
     
  2. dragricinMT

    dragricinMT 1/2 ton status

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    I have the edelbrock cam & lifters and performer intaake and edelbrock q-jet 1902 on my 400 and it works great. Comp Cams makes a roller kit that should work good also but is expensive. The edelbrock set-up works good.
     
  3. CaptCrunch

    CaptCrunch 1/2 ton status

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    you can make a heck of a lot more torque then that with a 400. The right cam should put you over 400 ft-lbs from idle to 4 grand with a peak at about 425 or so with stock heads. 450 or more would be possible with some better heads or some porting and a valve job to your stock ones.
     
  4. Heavymetal

    Heavymetal 1/2 ton status Premium Member

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    I'm all ears! What cam does that?

    Thanks,
    Mike.
     
  5. BorregoK5

    BorregoK5 1/2 ton status

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    Look into the Comp Cams 4x4 Extreme series, I'm running the smallest of them and I'm very happy with it's bottom end. You can make more with a larger one with less emphasis on the bottom end and more on higher rpm. The Retro roller cam in the same series is my target but is definately spendy when you get the rest of the adjoining roller gear. Run your setup past their tech department and see what they recomend as well as potential output.
     
  6. CaptCrunch

    CaptCrunch 1/2 ton status

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    I agree with BorregoK5. Keep small... a smaller one will take 15 hp or so off your motor, but the rpm level will be pretty dang high, the plus side is it will broaden your torque curve down low. I have been playing with the 250-256 roller cams. roller or not they should make 400 plus ft-lbs without batting an eye up till 3500 or so if not more.
     
  7. 84_Chevy_K10

    84_Chevy_K10 Banned

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    Just so you know, you're choking that 415. You'd have a LOT more power and not give up ANY (maybe even gain some) on the bottom end with a bigger cam. I have the smallest Comp Xtreme 4x4 in a 305 and I could even go bigger and still keep my low-end torque just fine. You've given up a massive amount of power with that camshaft and it's simply a gross mis-match of parts for that size engine.

    I'd look into the Comp 4x4 Xtreme series, and go at least one step up from the smallest in a 400. There are 4 of them. I'd say get the 2nd from the smallest or one up from that depending on how wild your 400 is.

    Bigger motors need more camshaft and won't lose their bottom end torque like a smaller motor. A 400 is a lot more motor camshaft wise than a 400.

    Run from the Edelbrock cam like the plague. It's too small and old technology. I'd look into Comp. Crank, Crower, Isky, and Lunati are all good too. I personally have a Comp.
     
  8. BorregoK5

    BorregoK5 1/2 ton status

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    That would be true if I wasn't running a lower than stock stall converter, stock intake/exhaust and small valve heads. In reality, its perfectly matched as I'll never use that much . If anything, the 750 cfm quadrajet is mismatched right now since I will only flow 500cfm at 4500rpm. When I replace the intake with a good air gap, get a set of larger valve/runner heads and open up the exhaust, then I'd be due for a new cam (which is when I'm stepping up to a roller cam). As for the torque converter, I'm going to remain small on the cam to accomodate it an keep the heat down in my tranny (those high stalls generate a lot of heat). This engine is built for fuel economy and a lot of low rpm grunt, like towing or slow crawling. If I'm not running it over 4500rpm on a regular basis and my duty cycle is between 1200rpm and 4500rpm 90% of the time, then it would be a waste to go bigger and not take advantage of matching the average duty range with the power band. It would be slower off the line, get poor average fuel mileage and be less then desireable most of the time. I've built a lot of muscle cars with too much cam, and its fun at the strip or for showing off on the weekend, but not a daily driver. I need all the torque I can as soon as possible to get this big beast moving.
     
  9. 84_Chevy_K10

    84_Chevy_K10 Banned

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    I completely disagree on the stall issue. Just because you have a bigger cam doesn't mean a stall torque converter will be necessary.

    DD 2000 most likely prove what I've said is true. Even with a bigger cam in your 415, you'd probably gain more torque from in the 1500-2500 RPM range, and I guarentee you'd gain some in the top end.

    My engine rarely sees more than 4000 RPM either, and even though yours has 30% more engine, you're breathing through the same camshaft. That makes no sense at all to me.
     
  10. BorregoK5

    BorregoK5 1/2 ton status

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    I'll use engine analyzer as an example, the right side shows which Extreme 4x4 cam grind was in use and which colors represent it on the graph. I have every detail of my engine loaded in right now (all corked up).

    http://68.64.55.51:81/images/camcompare2.jpg
     
  11. Heavymetal

    Heavymetal 1/2 ton status Premium Member

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    Ok, you have me sold on the extreme 4x4 camshaft. When I order it should I get lifters with it as well? And what about the stock valve springs, will they work ok with this cam. Thanks, you guys have been a big help to me.

    Mike.
     
  12. BorregoK5

    BorregoK5 1/2 ton status

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    I would, the complete kit is relatively inexpensive ($160) unless you go retro roller ($625). Just give comp a call, they wont steer you wrong, but do let them know what your targeting for the truck and how much you plan on using it at which rpms, it helps a lot.

    Forgot about the valve springs, if you go small its not a big deal but the larger you go there will be a recommended cut-off point. I'd highly suggest new springs for any of the retro roller cams.
     
  13. wayne

    wayne 3/4 ton status

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    Just for good insurance I would change the valve springs. Also get the lifters with the cam. If you want to free up a few more ponys get a set of the comp cams steel roller rockers.
    Back about 10 years ago I put a 268H cam kit in a 400. It was dropped in a 1970 MC which is a heavy car and that engine made gobbs of torque. It seemed to pull twice as hard as the stock 350 did and got better gas milage if you kept your foot out of it.
     
  14. 84_Chevy_K10

    84_Chevy_K10 Banned

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    I agree. Even Comp said I would not need fancy valvesprings for the smallest Xtreme 4x4. They did say I'd need them if I used a bigger cam and that's part of the reason why I have the smaller one. They'll reply by email too.

    BTW, your pictures come up access denied. I would like to take a look though.
     
  15. BorregoK5

    BorregoK5 1/2 ton status

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    I emailed them to you, some peoples ISP's wont let them look at that web port.
    This is a cool discussion, I think its important for people to share what they have and how it works so others can use that info to figure out what works for them. I guess thats one of the hardest parts to owning an engine which is so fully supported by after market components, eh?
     
  16. BorregoK5

    BorregoK5 1/2 ton status

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    First look at the 415stock with the two cams, the smaller one makes more power sooner untill about 3300rpm and then the gain is minimal.
    Now take a look at the second chart showing 415stock and 415goal. This is where a higher stall would make all the difference. At 2200 rpm my power band kicks in and you'll see the opened up engine crossed the corked engine, but up untill that point, the corked engine is faster and stronger. I ran a stock production 305 with the whole range of 4x4 Extreme cams for you and I think you made a wise choice with the cam you have now, but thats assuming you have a totally stock engine. I'll mail you the results so you can check it out. I've used DD 2000 too but it doesn't take as much into account and always seems to give me exagerated autopian figures. I keep falling back to engine analyzer even though my numbers are always lower.
     
  17. dyeager535

    dyeager535 1 ton status Premium Member

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    Just for fun, (and for all playing along in their own copy of DD2K) I ran a 412 (.060 over apparently) in DD2K with Vortec 1.94/1.5 heads, HP manifolds (which I imagine as being true duals with manifolds) dual plane intake, and the Crane hr260-12 vs the Wolverine (comp now?) WG1168, which is a dual pattern flat tappet Olds grind.

    WG1168
    HP Manifolds/Flat tappet:316hp@4500/426ftlbs@3000
    add Small Tube headers:350hp@4500/449ftlbs@3500
    change cam to roller: 341hp@4000/516ftlbs@2000

    Crane HR260-12
    HP Manifolds/Flat tappet:293hp@4000/433ftlbs@4000
    add Small Tube headers:326hp@4500/458ftlbs@2000
    change cam to roller:311hp@4000/514@2000

    I tried with 2.02/1.6 valves, that didn't hurt either...the peak was later, but at the previous peak RPM's, the numbers were still a bit higher, so no loss with bigger valves at least in the higher RPM's.

    Some things to consder though.
    A)DD2K doesn't properly reflect the roller cam increases...personal experiences have been that the difference between flat tappet and roller isn't that big.
    B)these are peak numbers, and only measured 2000RPM and later. Whats going on under the 2000RPM limit isn't known/shown, but if the curve is going DOWN at 2000RPM, prety much indicates even higher numbes under 2000.

    Just something more to play with : )
     
  18. BorregoK5

    BorregoK5 1/2 ton status

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    Actually, its .30 over for the 415 as follows:
    Bore: 4.155
    Stroke: 3.832
    Rods: 5.7

    You bring up a good point on the heads as related to peak power. The 415 makes all its power very early on and low in the rpms so a larger valve head which increases the overall flow doesn't effect the peak hp/tq numbers as much since were not hitting those at peak rpm, but the 305 figures I ran had its peak numbers at peak rpm (heads didn't improve much here at all but a free flowing exhaust made a ton more mid-range!).
     
  19. TopOff

    TopOff 1/2 ton status

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    If it helps anyone, I am running the WG1168 in my 383.

    crazy torque off idle. Missing something above 3k...HP? timing?

    Anyways, I am getting ~14 MPG with 3.73 gears
     
  20. BorregoK5

    BorregoK5 1/2 ton status

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    Are you running all stock accesories? Mine felt like that before I re-curved my ignition... could be related but there are quite a few things which could cause this. I'm running 3.07's and yeah, around 14mpg. I'm building a 383 right now... whats your setup?

    And one last chart because I felt it was the most important comparison I made when making my selection and which finally narrowed my search down to the small cam. The low figures are the small cam corked up and the high figures are both the same cam and a step up retro roller cam... theres not a whole lot of difference between the two once the engine is breathing well, it really came down to price verses performance at that point.
    <a target="_blank" href=http://68.64.55.51:81/images/decided.jpg> Deciding Graph </a>
     

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