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05-11-2009, 05:13 PM | #1 |
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Location: Westminster, Maryland
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1.6 rockers and powerband
so, i wiped a lobe off of my XE274, and i'm looking into going bigger with my cam, I have a ~3000 stall and dont want to take it past 7000, 3.73 rear. I am using 1.6 rockers and was wondering about the effect the higher ratio had on the powerband of the cam. cam suggestions would be nice too thanks.
I'm running a 383 with iron eagles (180/72cc) and a dart kool can |
05-11-2009, 06:47 PM | #2 |
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Re: 1.6 rockers and powerband
I am not a fan of the XE line so take this with whatever weight you wish.
If you want a realistic cam recomendation, you really need to offer up a little more info. Need true compression ratio (if you truely easured and have it, if not please list the components,, piston #, deck clearance if known or if the block was decked, gasket, to go with the head cc). What intake / carb your running and some exhaust details. but from the hip... with a 3000 stall and 3.73 gears , a 7000 rpm limit,, we already know a few limits. We want a cam that has a effective limit in the 2500-6800 range, The Iron Eagles are a little lame on the exhaust side. so we definately need a split pattern. If we knew compression we could make a good stab at 0.050" duration, then just need to know the max lift the springs will allow ( The IE's have a 1.42" spring and a .60 max lift as I remember ) but what is Valve-to-Piston clearance now with the .525 lift you have with the XE274 and 1.6 rockers?? The higher rocker ratio will probably do nothing if anything to effect the power band. It increases lift, which has a VERy small effect on the 0.050" duration. Enough to move the power band,, unlikely. If you were to step up to the next hydraulic in the Comp flat tappet line the XE282H you would jumop about 6 degrees of duration to 240° @ 0.050" and slightly wider split pattern but still not enough lift IMO. If you looking to step up to the real potential of those heads I would like to see AT LEAST .575 lift, and more like 0.050" off coil bind for something real close to .6" lift. Unfortunately that would mean a custom cam, or a roller. Have you considered the cost vs. power of going to a hydraulic roller? Lots of nice hydraulic rollers out there that will put lift in the sweet spot of those heads, and can be had in whatever duration you need to match your compression (once you have that info)
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Still playin with trucks, even at my age! When you're dead, it's only a problem for the people around you, because you don't know you're dead. .....It's kinda the same when your STUPID. I just did my taxes and reviewed my SS statement. Thanks to the current administration it looks like I will only have to work till noon on the day of my funeral. |
05-11-2009, 10:30 PM | #3 |
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Location: Westminster, Maryland
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Re: 1.6 rockers and powerband
thank you very much, Marv D, CR is right at 9.5, intake is a dart kool can, carb is some old holley 750, but thats up for reconsideration Exhaust is hedman step tubes, 3" pipe with moroso spiral flow mufflers
I was actually leaning more towards a solid flat tappet, but i can't find any of the good articles on a roller cam, although it did cross my mind. as far as valve/piston clearance, i'm not sure, i wasn't to concerned with only 525 lift. i'm also not sure about max lift, but i wouldn't mind doin a little head work if it would be worth it. thanks so much for your help, i'm basically clueless as far as this goes |
05-12-2009, 07:05 AM | #4 |
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Re: 1.6 rockers and powerband
I have a buddy with a set of retro hyd roller lifters for sale if you go that route.
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Kevin Special Thanks to All who have helped on the TRUCK! My Pass Time Show http://s129.photobucket.com/albums/p...Chapter1-0.mp4 So Far my best Times are: Motor only: 6.44 1/8 @ 104.13 10.39 1/4 @ 125.83 Nitrous Times: 5.785 1/8 @ 118.65 with a 1.336 60ft 9.168 1/4 @ 142.58 with a 250 shot dead out of the hole! |
05-14-2009, 05:25 PM | #5 |
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Re: 1.6 rockers and powerband
not sure, but if i do, i'll let ya know
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05-14-2009, 08:44 PM | #6 |
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Re: 1.6 rockers and powerband
IMO with todays oils, if you put any mileage on that motor, go roller. With 9.5 SCR, going big is going to reduce bottom end TQ.
Food for thought, you can run up to about 8.5 Dynamic compression on pump gas before you really need to start turning the timing down. With only 9.5 Static, a cam ground on a 104 intake center having 267* at .006 would net 8.0 DCR. We are talking roughly a 218* at .050 for a decently agressive hyd roller profile. Not very big at all and would be hard pressed to get you to 7k rpm. To get you to 8.5 on a 104 ICL it's have to be a 246* @ .006 which would be extreamly hard to find and definately will not get to your 7k very easily. A 224-230* intake duration cam at .050 could get you to 7k if set up properly. Thats roughly 274* at .006. This drops your DCR to 7.84..
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------Motor---------------Bottle 60'---1.53---------------1.41 1/8---6.58 @ 105.92----5.87 @ 118.41 1/4---10.38 @ 126.97----9.24 @ 142.49 |
05-14-2009, 09:17 PM | #7 |
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Join Date: Jul 2007
Location: Upland, CA
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Re: 1.6 rockers and powerband
check out Lunati's voodoo hydraulic flat tappets. i took the biggest one they had (pt # 60105) and stuffed it into my 350 w/ world sportsmans 64cc 200cc 9.5 cr, 3000 verter, 3.73's and i'm running 1.6 full rollers so the lift is up a bit. long story short...my truck is very very different now. in a good way. it idles at 950 in gear and the fun really starts at 2500 and i don't know where it ends yet. this is on chevron ca 91 octane pump gas with and edel 650 and dual plane and i use valvoline racing oil 50 with zinc- 3.99/qt at auto zone. I'd say Lunati's voodoo hyd ft cam are worth checking out for what you want. Have fun.
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05-15-2009, 09:55 AM | #8 | |
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Re: 1.6 rockers and powerband
Quote:
__________________
Still playin with trucks, even at my age! When you're dead, it's only a problem for the people around you, because you don't know you're dead. .....It's kinda the same when your STUPID. I just did my taxes and reviewed my SS statement. Thanks to the current administration it looks like I will only have to work till noon on the day of my funeral. |
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05-15-2009, 12:48 PM | #9 |
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Re: 1.6 rockers and powerband
Marv,
There are still small shops around making killer products. Take Elgin Cams for instance in Redwood City..
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------Motor---------------Bottle 60'---1.53---------------1.41 1/8---6.58 @ 105.92----5.87 @ 118.41 1/4---10.38 @ 126.97----9.24 @ 142.49 |
05-15-2009, 02:00 PM | #10 | ||
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Re: 1.6 rockers and powerband
Quote:
Here is a brief Bio he posted - Quote:
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- Greg |
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05-18-2009, 10:38 PM | #11 |
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Location: Westminster, Maryland
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Re: 1.6 rockers and powerband
So actually, i think i've decided on a roller cam. since i never do things right the first time, figure i'll just do it more than right and not have to worry about it
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05-19-2009, 12:09 PM | #12 |
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Location: Wetumpka, Al, U.S.
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Re: 1.6 rockers and powerband
full roller or hyd. roller?
__________________
Kevin Special Thanks to All who have helped on the TRUCK! My Pass Time Show http://s129.photobucket.com/albums/p...Chapter1-0.mp4 So Far my best Times are: Motor only: 6.44 1/8 @ 104.13 10.39 1/4 @ 125.83 Nitrous Times: 5.785 1/8 @ 118.65 with a 1.336 60ft 9.168 1/4 @ 142.58 with a 250 shot dead out of the hole! |
05-25-2009, 04:47 PM | #13 |
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Location: Westminster, Maryland
Posts: 411
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Re: 1.6 rockers and powerband
hyd roller, I think I've decided on the Comp cams magnum 286, if ur buddy still has those lifters, i may be interested
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