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#1
07-20-2009, 12:57 PM
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389 Rebuild **Camshaft Selection**
Ok.....my motor is out and pulled apart, getting ready to send block to shop. Probably going to bore at least .030 over. I am thinking of going with an 068 cam. What do you think? Looking for mild mannered street engine with a little more ummph.
Catalina 2 d HT (originally 2 bl--a/c car) 1964 389 w/stock 9773345 heads Weiand 4 bbl intake w/Holley 650 cfm DP Turbo 400 Tranny / stock converter Pertonix Ignitor II Not sure what the rear gears are probably pretty high....2.92/3.11 range? I don't plan to change the heads unless I just have to. I need to know the brand and model # of the best cam for this.....Please tell me your opinions . Thanks.
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Last edited by Tanksta; 07-20-2009 at 01:10 PM. |
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#2
07-21-2009, 06:21 AM
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You do not have enough rear gear for that cam or for that dubble pumper to work right!
While the motor work is being done you need to get the heads set up for screw in rocker studs and push rod guide plates, get the heads bowl ported by someone who knows what they are doing and then with those gears I would run a 067 cam with 1.65 roller rockers and you will end up with far more power than the 068 cam but with far more drivability, also you need a vacume secondary 650 or 700 carb, or better yet a Q-jet on a latter manifold. If you do opt for the bowl porting you should also have them gasket match the heads intake flange,BUT LEAVE THE EXHAUST FLANGE THE STOCK SIZE, as it has plenty of area to flow 180 cfm witha reworked exh bowl.
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Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
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#3
07-21-2009, 10:18 AM
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I agree an 067 with the 1.65's would be a better choice. Even with up to a 3.43 gear on a 26" tire.
And also as Steve said, go to screw in studs. For a cam in the middle of the 067 and 068 this one by Bullet could run well. Maybe contact them. www.bulletcams.com 163256 208 256 420 111 H 163256K Smooth idle, good mileage and torque
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68 Firebird Are you running with the wind or breaking it? Last edited by Ron H; 07-21-2009 at 10:23 AM. |
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#4
07-22-2009, 08:10 PM
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I talked to a tech at Comp cams today and they recommended the XE262H grind (51-222-4). What will this do with those high compression heads? I may have been to high with the rear gears...may be be more in the 3.23-3.40 range? To be honest I have no clue. I think when I first got the T400 installed if I was doing 70-75mph it was in the 2100-2200 rpm range. Sorry guys I know it isn't much help. The machine shop is going to try to get by on a .030 over and he said something about the crank did a 10 10?
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#5
07-22-2009, 09:19 PM
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It's easy to figure out what your rear gear ratio is.
Jack the rear up. Put it in nuetral. Mark the tire and another point, like your fender. Have someone rotate the tire 1 revolution and count how many times the driveshaft turns in that one revolution. It will get you close. I like and use bullet U/D cams. That comp cam is close to an 068. Do you know what your CR will be after the overbore? I believe the xe cam would be better suited to a 9 to 1 or so CR. I have one through the numbers to see. Maybe SC or Bruce Wilkie will chime in.
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68 Firebird Are you running with the wind or breaking it? |
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#6
07-23-2009, 09:08 AM
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Cam choice/ Pontiac Gregg
The 067/068 cams will work if you are sticking with press in studs.( only .407" lift) Now I you go to screw in studs, I'd get an Ultra-Dyne 280/288H12+6.
It's worth 30 + horse over the old school cams. DON'T RUN 1.65 ROCKERS !! Pontiac Gregg
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Greg Merrick |
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#7
07-24-2009, 12:15 AM
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I'm going through this ordeal right now. ARP makes the 1/2" 13 x 7/16" rocker stud. You'll just need to go to an adjustable nut like the chevy guys use, good for 1 or 2 uses. That way they can still fit under the stock valve covers but you'll need to get a set of the extra thick rubber (about 1/4") reinforced with metal valve cover gasket Kauffman Racing sells them. There may be others that sell them, I just get most of my stuff from them.
I'd get a comp Extreme Energy .230/.236 @ .050 110 LSA and wake that mother up. It will sound awesome when you pull into a cruise night but it's not so big that you loose driveability. Stay with 1.5's Also, get about a 15 to 20 cc piston dish to drop your compression from the 10.75 range into the high 9's so you can run pump gas without detonation.
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You know it's going to be a good day when you wake up breathing! |
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#8
07-24-2009, 12:21 AM
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I see a few recommendations here for the 067 cam.
My question is, where can you buy an 'off the shelf' 067 cam these days without paying for a custom grind? The 066 and 068 are both easily available, but I wasn't aware that the 067 could be had as it wasn't being reproduced for many years. |
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