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Comp Cams Magnum 270..any thoughts??

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Old 04-03-2003, 12:55 AM   #1
Aaron-74
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Default Comp Cams Magnum 270..any thoughts??

Now that my XE-262 is toasted, and I'll be uping the compression. I've been thinking about the Magnum 270. It will allow me to keep the stock stall whichi want to do. And it suposedly give a bad butt idle. Anyways..anyone have any comments on this cam??

Thanks,
Aaron
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Old 04-03-2003, 01:15 AM   #2
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Default Re: Comp Cams Magnum 270..any thoughts?? (Aaron-74)

When I bought my car it had one stabbed into an otherwise stock L-48 with 3.08 gears. It didn't work anywhere, but it did have a sweet idle.
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Old 04-03-2003, 01:17 AM   #3
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Default Re: Comp Cams Magnum 270..any thoughts?? (ORVette)

I've got a very none-stock motor with 3.70'w..


How was the idle quality and did the cam really effect power accesories??

How sweet was the idle?? :reddevil
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Old 04-03-2003, 01:34 AM   #4
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Default Re: Comp Cams Magnum 270..any thoughts?? (Aaron-74)

I've been kicking this around too... "biggest cam for use with stock converter" does this mean it makes enough low torque to get a good launch with the stock converter or does it just mean the car is kinda still driveable with the stock converter. I've got some '65 fuelie 327 heads I wanted to put on my L48 but 9.7:1 seemed like a lot for the stock cam... none of that really matters to me now though as the 350 is coming out with a noise (sounds like the timing chain is hitting the cover) and I'm finally gonna plug the 396 in :yesnod:
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Old 04-03-2003, 01:53 AM   #5
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Default Re: Comp Cams Magnum 270..any thoughts?? (Aaron-74)

Aaron:
If you've got the compression ratio to back it up, why not step the cam up? Changing the convertor is not a big deal (other than paying the extra $$ for the convertor itself). At any rate, I have a buddy who has that cam in his 70s Z28 Camaro. It is in a 350 and has a pretty lumpy idle, he also chose the Magnum 270 because he wanted to use the stock convertor.

It just seems like this. If you have the compression ratio and I know you have the rear gears (3.70) to back it up....why not step the cam and convertor up. If you do choose to stay with the stock convertor, I would say the 270 Magnum is one of the better cams you could select.
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Old 04-03-2003, 02:03 AM   #6
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Default Re: Comp Cams Magnum 270..any thoughts?? (bence13_33)

Good question Bence. I do have the compression,but my heads are the limiting factor right now. Basically I'm running stock L-48 heads with a lot of porting and bigger valves. But they still don't flow SUPER well. And I don't want to get too crazy with the cam. When you start needing a 2500 stall in a daily driver..then it really shouldn't be a daily. And I don't really have the money for the convertor,cooler, all the machine work I need done to the motor along with the new cam and lifters. Comp sales a Mag 270 cam and lifter kit for 170.00$. After that I've got about 400.00$ in machine work to look forward too, probably.
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Old 04-03-2003, 02:04 AM   #7
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Default Re: Comp Cams Magnum 270..any thoughts?? (Aaron-74)

That is the cam in my car but I have a 2200 stall converter. It seems to work nice. If you want a ride just tell me.

Pat
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Old 04-03-2003, 02:12 AM   #8
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Default Re: Comp Cams Magnum 270..any thoughts?? (PatG)

Hell yeah..

I haven't seen your car in forever. But I always like the way it sounded. I think the last time I saw it was when we all used to meet up on 1960 at the starbucks..

How is the "off the line" power??
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Old 04-03-2003, 02:31 AM   #9
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Default Re: Comp Cams Magnum 270..any thoughts?? (Aaron-74)

I was just over when we pulled the motor out of Ken's car a few weeks back. Power is good but my battery seems to be dead right now. I am going to hook it up to the charger tomorrow to see if it will take a charge, it would not start after driving it so I think it is gone. How soon do you need to make the decision on buying the cam?
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Old 04-03-2003, 07:04 AM   #10
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Default Re: Comp Cams Magnum 270..any thoughts?? (Aaron-74)

i have the 270 in my 61.
check the book for your stall speed. it is2100 stock on my 72 for example. But the cam is asleep at 1800.
any new cam i buy will be solid lifter.
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Old 04-03-2003, 07:28 AM   #11
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Default Re: Comp Cams Magnum 270..any thoughts?? (Aaron-74)

When comp cams says "biggest cam with stock convertor" , in the real world that means run 2500stall. In my opinion, they understate the negitive effects of perf cams on the bottom end. I use to have the XE268 and that cam was listed as "ok for stock convertor", But even with a 2400stall I could feel the loss in bottom end. I wouldnt touch the Magnum 270 in an automatic trans car without roughly 2500 stall. Espesially in a 350. A bigblock 454 would probably be ok without higher stall since they have gobs of tq anyway. Plus, more cubes mellows the negitive effects of performance cams. Thats my opinion.


[Modified by Jvette73, 5:28 AM 4/3/2003]
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Old 04-03-2003, 07:39 AM   #12
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Default Re: Comp Cams Magnum 270..any thoughts?? (Jvette73)

2500 stall is very decent in a daily driver. Its a mild convertor. It doesnt stall at that speed all the time. When your easy on the throttle it delivers power long before 2500. The 2500 is brake stall speed. IE when you hold the brake and run the r's up a bit, then simultaenously, release the brake and punch the throttle, then you get the higher stall. And with a 350 and a 2500 convertor, your actual stall speed would probably be less. Stall speed is effected by the ammount of tq an engine produces. So a 350 with a Magnum 270 will have reduced bottom end tq and thus produce a lower stall speed from a given convertor. You might find an advertised 2500 vert, coming in around 2300.
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Old 04-03-2003, 08:00 AM   #13
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Default Re: Comp Cams Magnum 270..any thoughts?? (Jvette73)

I put one in the engine that came in my 72 (76 8.5:1 305)...before I ran the #'s and knew what it was....it sucked in that engine. No power below 3,000 and the heads didn't flow enough to rev over 4,500...This was a 4 speed car with 3.08's. Idle sounded bad-azz though.

The car was actually more fun to drive with the mystery cam that came in it (much milder, whatever it was) and was faster to boot (16.2 after cam swap, 15.8 before). It did pull well in it's 1500 RPM power-band though...With your higher compression, cubes and head work, you will probably have better results than I did.
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Old 04-03-2003, 08:44 AM   #14
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Default Re: Comp Cams Magnum 270..any thoughts?? (randy72)

I had an XE-262 which doesn't seem to be all that much smaller than the magnum 270. about .01 on lift on the exhaust side. Just a tad more durration.

Pat-By next wednesday.

I'll probably just call comp today and pass all the guess work.
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Old 04-03-2003, 10:24 AM   #15
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Default Re: Comp Cams Magnum 270..any thoughts?? (Aaron-74)

Aaron, as an alternative to the Comp Cams you might want to look at Crane. I have a Crane Max Velocity 272 cam in my 74 and I like it a lot. It has a noticeable idle but pulls nicely on the bottom end and really wakes up at 2000 rpm. I pull 15 inches of vacuum at idle so all the accessories work well. The new nomenclature for the cams is PowerMax and they are listed up to a 278. I can lug this cam down to 800 rpm in 4th gear but the cruise is around 2500. Here are the specs
Crane HMV-272 Max Velocity dual pattern hydraulic cam. The cam has a duration of 216 degrees intake and 228 degrees exhaust @ .050 lift and has a max lift of .454 inches on the intake and .480 on the exhaust. I believe the lobe centers are 114 degrees.
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Old 04-03-2003, 11:22 AM   #16
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Default Re: Comp Cams Magnum 270..any thoughts?? (Aaron-74)

I had the 270H in my 77 Camaro with a B&M Holeshot 2000 converter.
The combo worked very well.
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Old 04-03-2003, 11:30 AM   #17
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Default Re: Comp Cams Magnum 270..any thoughts?? (Aaron-74)

When I built mine I inquired about getting the "biggest cam I could so to use the stock convertor" too. I had just rebuilt the trans and the torque convertor was new. I wound up with this cam here :

http://dab7.cranecams.com/SpecCard/D....asp?PN=113942

It has a good idle and lots of power. But I wound up getting the 2500 stall convertor later, just to get hole shots. :lol: :blueangel:

So I had lots more labor to go into it and do it twice. :nonod: :nono:
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Old 04-03-2003, 11:36 AM   #18
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Default Re: Comp Cams Magnum 270..any thoughts?? (Aaron-74)

I called comp last year about this cam and the XE's 262,268.
I was told with a 350,4 speed,373's use the XE268 with 9.5 and under and the 270 over 9.5 CR.
They said to use the XE268 over the 262 with a manual. I haven't got to that point of the work yet so I can't say how it worked.
Gary
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Old 04-03-2003, 12:22 PM   #19
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Default Re: Comp Cams Magnum 270..any thoughts?? (gtr1999)

Great all around street cam needs 10:1 compression. I could tool around at 1200 RPM in 4th with 3.08's and it still turned on good at the higher RPM's. Real "nice" idle too :D
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Old 04-03-2003, 01:41 PM   #20
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Default Re: Comp Cams Magnum 270..any thoughts?? (MotorHead)

I just had the 270 installed in my BB rebuild. I am picking up the car either today or tomorrow.

I was told it was going to be too mild for my application from some of the forum members, but my engine builder pushed it and so did Comp Cams, so I went with it.

I guess what sealed it is Comp Cams claim that it is the perfect cam for cruising, which is what I do.

Good luck
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