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11-28-2013, 12:06 PM | #1 |
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Join Date: Apr 2010
Location: Hagerstown, MD
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Engine Gurus Chime in
Okay, I have been toying of tearing into my motor. It isn't just any motor...its a BBC LS6 454 Crate motor. It was built at the end of the production run in 1992 and has about 50K on it.
Some of you may know that this was a special motor because of all the race stuff it has. It is a good motor but I want to change out the cam and valve train to something better and quieter (It is a solid roller cam with a very smooth idle but slightly noisy). I have looked around at cam kits but can't make a decision because I really don't know how they will act given the 11:1 compression. Right now the motor doesn't get going till about 3500RPM and I'd like that to change to something around the 1800 with a strong wide band to 5500-6000 rpm. I'd also like a good quiet rumble at idle so not too much overlap. So the question: What would be the best cam set to get? I'm also considering changing out the rockers too and converting to TPI. Do you all have any suggestions? Motor has rectangle port cast iron heads. Or should I just switch it all to an LS motor? I'd like a LQ4 with a 68mm turbo set-up, but Big Blocks look sweet in our trucks! Thanks for the help!
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John Paap Ole Greenie Hagerstown, MD My Mistress 70 CST Short/Step LS 5.3/4L65E New motor install Thread:http://67-72chevytrucks.com/vboard/s...d.php?t=667773 |
11-28-2013, 12:17 PM | #2 |
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Join Date: Feb 2000
Location: Center City, MN, USA
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Re: Engine Gurus Chime in
Trade it to a Chevelle guy for a trillion dollars and build up a sweet LS
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'70 cab, '71 chassis, 383, TH350, NP205. '71 Malibu convertible '72 Malibu hard top Center City, MN |
11-28-2013, 12:22 PM | #3 |
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Join Date: Jul 2012
Location: Ft Wayne Indiana
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Re: Engine Gurus Chime in
A simply smaller cam is what you want.
Personally, I'd go LS. It's the only way to get power, reliability, and gas mileage. Something that is extremely hard to do with engines of the past. If you have deep pockets, you could go LSX454. Won't get great mileage, but as long as you keep fuel injection and put a good overdrive trans behind it, it shouldn't be too bad.
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71 K20 64 GMC mud truck |
11-28-2013, 12:26 PM | #4 |
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Join Date: Nov 2012
Location: ravenwood, mo
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Re: Engine Gurus Chime in
Give chris straub a call and tell him exactly what you have and what you want it to do. He will get you set up right the first time! Have you checked into switching over to a hydraulic roller setup?
http://www.straubtechnologies.com/ |
11-28-2013, 12:38 PM | #5 | |
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Join Date: Apr 2010
Location: Hagerstown, MD
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Re: Engine Gurus Chime in
Quote:
Yes, only looking into hydraulic roller set-ups...quieter = Hydraulic roller. The solid roller set up is really made for higher RPMs which is more for race applications...one thing for sure, all the old school motor guys know what it in it just by hearing it. I'll check into Straub and see what he says. Just too many variations in cam selection...lift, duration, lobe separation, etc!
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John Paap Ole Greenie Hagerstown, MD My Mistress 70 CST Short/Step LS 5.3/4L65E New motor install Thread:http://67-72chevytrucks.com/vboard/s...d.php?t=667773 |
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11-28-2013, 02:03 PM | #6 |
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Join Date: Nov 2012
Location: ravenwood, mo
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Re: Engine Gurus Chime in
That's the greatest thing wit calling Chris. He will know what your heads are flowing and build you a cam accordingly. You don't have to do any of the math! He also uses Morel hydraulic lifters, which have proven to be reliable and worth every penny. A lot of the big inch bbc guys use his cam and lifter packages for both street and strip with great success. Just an idea of what he's doing: My 496 build consists of afr 265 cnc chamber heads, eddy air gap, 900 ultra hp, one of Straubs cam and lifter setups, comp gold seriesrockers, Scat internally forged rotating assembly and Mahle 18cc dome pistons. My motor isn't quite ready for the dyno, however I followed a build off of 3 other guys with this exact setup. Their motors have all been to the dyno and they are showing anywhere from 700-780hp with 690-750 ft lbs. Those all vary because of different cam grinds and needs of the motor. The greatest thing about these setups is that power comes on instantly and quits at 6400 rpms! Keep in mind that these are hydraulic roller motors on fairly small cubic inches! He's definitely worth the phone call! While I'm running the smaller AFR heads, his cam design is able to take full advantage of the airflow. I'd put down a hundred dollar bill that with his cam, your motor won't only make more power, but it will do so in your desired rpm range. I'm talking about 600+ ft lbs at 2000 rpms! Of the dyno sheets that I've been able to study with this setup, the torque stays within 7% of the full rpm range. Todays technology is awesome to say the least!
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11-28-2013, 03:16 PM | #7 |
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Join Date: Aug 2008
Location: Cedar Park, Texas
Posts: 7,500
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Re: Engine Gurus Chime in
You can also call the comp cams 800# for a cam recommendation. I have never been steered wrong. Have as much info on your truck ready as possible
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