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COMP CAMS Magnum 270H in a '77 L-48?

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Old 03-07-2002, 02:07 AM   #21
PatG
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (love to drive)

I have a 270H in my 79 with a ~2200 stall converter. I also went with a trans cooler that I picked up from a friend who bought it and did not use it. I feel the cam is pretty nice for HP but still has a nice idle (just a bit of lope) and I can pass exhaust emissions with it.
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Old 03-07-2002, 02:41 AM   #22
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (love to drive)

I wouldn't go over a XE262 with a 3.08, I've just put one in my car (I have 3.08's) and I am sweating if I'm going to give up too much low end. I also removed a cam that had similar power ranges that the 270H had. It was not a good match for a stock torque converter and 3.08 gears, it was very sluggish on the low end. I've already decided that if the XE262 doesn't give me the performance I'm looking for, I'll put a 2200+ stall in when I install my TH200-4r. I'm also looking at getting some 3.70 gears.
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Old 03-07-2002, 10:38 AM   #23
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (MotorHead)

Quote:
HP up gas mileage down :D

I run a 270H Magnum, great cam but I have a four speed, you might be pushing
it without high performance torque converter. I do believe I read somewhere that Comp Cams says the 270H is as far as you can go stock, might want to check their web site.

Gas mileage will go down ......BUT YOU WILL NOT CARE I PROMISE :yesnod: :lol:
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Old 03-07-2002, 10:41 AM   #24
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Default Re: COMP CAMS Magnum 270H in a '77 L-48? (love to drive)

I ran the 270H cam in a 77 Camaro a few years back. Also had an B& M converter, around 2200, Tans cooler and 342 posi. Shift kit in the tranny. The car was still very streetable.
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Old 10-15-2011, 09:34 AM   #25
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The 270h is the highest cam you can go with stock converter, but it will work best with a 2000+ stall. The swap time doing a converter away is about an 11/2- 2hrs. The most time consuming part is removing the tranny. The 270 cam is alittle bit higher lift and duration over the recommended replacement cam suggested for the L-82 motor "268" grind.
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Old 10-15-2011, 12:15 PM   #26
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Quote:
Originally Posted by MotorHead View Post
HP up gas mileage down

I run a 270H Magnum, great cam but I have a four speed, you might be pushing
it without high performance torque converter. I do believe I read somewhere that Comp Cams says the 270H is as far as you can go stock, might want to check their web site.

Technical advisor Aaron Mick at CompCams told me, for my bone stock
L48 350 ,that the 262H was end of the line for stock converters.
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Old 10-15-2011, 12:36 PM   #27
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I used the 270 magnum in a 77 l-48 and it really woke it up and without a stall it idled fine, lots of power.
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Old 10-15-2011, 02:30 PM   #28
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It might idle fine, but what intake you gonna swap to? The issue here is, the 3.08 rear gears with the low stall speed. Might make GREAT peek power, but be an absolute DOG off the line, meaning, no fun.
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Old 10-15-2011, 02:35 PM   #29
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Change the torque converter first. Then keep a look out in the Parts for sale section for a good used rear with 3.55 gears. It's an easy swap and will net you an immediate 15% torque increase to the wheels. It's sort of like increasing your engine power from 300 to 345 HP. And if you combine that with a 2000 stall converter you will be a very happy driver!

John
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Old 10-15-2011, 05:53 PM   #30
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Quote:
Originally Posted by Tim H View Post
I used the 270 magnum in a 77 l-48 and it really woke it up and without a stall it idled fine, lots of power.

Was going to overhaul my motor and install my 262H this winter.Was thinking about 1.6 rockers,but wanted to see how it ran with the 1.5's first,but if a 270 idles fine with a stock converter then I think I'll go ahead and go with the 1.6's with the 262H.Should'nt be that much more lift....or?
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Old 10-15-2011, 11:13 PM   #31
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Quote:
Originally Posted by Ravoll View Post
Was going to overhaul my motor and install my 262H this winter.Was thinking about 1.6 rockers,but wanted to see how it ran with the 1.5's first,but if a 270 idles fine with a stock converter then I think I'll go ahead and go with the 1.6's with the 262H.Should'nt be that much more lift....or?
You have to watch running 1.6 rockers if your heads haven't got elongated pushrod holes in the heads or the pushrod will rub a hole in itself up against the too small of a hole.
Im not much on the 1.6 rocker thing, instead of trying to make a lesser cam more just get a bigger cam.
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Old 10-16-2011, 12:42 AM   #32
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10 years later, do you guys think the OP bought the 270h?
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Old 10-16-2011, 05:58 AM   #33
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Quote:
Originally Posted by Tim H View Post
You have to watch running 1.6 rockers if your heads haven't got elongated pushrod holes in the heads or the pushrod will rub a hole in itself up against the too small of a hole.
Im not much on the 1.6 rocker thing, instead of trying to make a lesser cam more just get a bigger cam.

Of course one could machine the holes if they rub.Not that big a deal or?

The rockers I was thinking about is the RP1416-16 package from CompCams,(stamped steel roller tips).

The cam kit is purchased and here.Purchase price, shipping ,and import tax = $675.29 to get it to Germany,I kinda really need to use it, or my old lady will pitch.
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Old 10-16-2011, 10:05 AM   #34
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Quote:
Originally Posted by MotorHead View Post
HP up gas mileage down

I run a 270H Magnum, great cam but I have a four speed, you might be pushing
it without high performance torque converter. I do believe I read somewhere that Comp Cams says the 270H is as far as you can go stock, might want to check their web site.
Even with the 262 from comp, the drivability was great before I put a 2400 rpm stall in, but the fun factor was a lot better after the stall converter especially since I stuck with the stock gears. You might want to match the camshaft to your compression ratio, I don't know about your L-48, but mine came stock with only 8.5 to 1 compression.
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Old 10-16-2011, 10:28 AM   #35
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Quote:
Originally Posted by Ravoll View Post
Of course one could machine the holes if they rub.Not that big a deal or?

The rockers I was thinking about is the RP1416-16 package from CompCams,(stamped steel roller tips).

The cam kit is purchased and here.Purchase price, shipping ,and import tax = $675.29 to get it to Germany,I kinda really need to use it, or my old lady will pitch.
Wheres that grinding metal going to go?
Seriously, what I do is buy the Comp Cam, Summit $48 lifters and a cloyes roller timing chain and related parts and im fine with that.
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Old 10-16-2011, 11:54 AM   #36
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2002 is calling, they want their thread back.

Anyway as I remember I did the swap and at the time the Comp website said it was the biggest cam you could put in with stock converter.

I did the cam swap first and didn't notice too much, if you don't feel it your looking at less than 15hp. Once I put the Sportsman II heads on it was a different story, it was near 300HP at the rear wheels, big difference so cam alone won't do much

I don't remember if I had the heads on at the time I posted or not. But changing to the 64cc chamber heads, 1.6:1 rockers and a very thin steel shim gasket did the trick. I also think I had flat top pistons in there at this point and compression ratio around 10:1 so you might as well say the engine was rebuilt, so just a cam change is not going to do to much


Last edited by MotorHead; 10-16-2011 at 12:04 PM.
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Old 10-16-2011, 12:10 PM   #37
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His cam probably went flat eons ago lol

Ran a Isky 270 in a 9.5 to 1 el cheapo shortblock, cruddy 882 boat anchors, Edelbrock rpm intake, 600cfm :cough: eddy carb 1-5/8 headers it ran pretty strong. 2400 stall would be fun.
Good all around street cam
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Old 10-16-2011, 01:15 PM   #38
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Quote:
Originally Posted by Tim H View Post
Wheres that grinding metal going to go?
Seriously, what I do is buy the Comp Cam, Summit $48 lifters and a cloyes roller timing chain and related parts and im fine with that.
The metal shavings will remain on the workbench.This is all being done with a complete overhaul.
To late to buy other new parts.Already have them.
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Old 10-16-2011, 02:38 PM   #39
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Ravoll,
We haven't talked much about the 1.6 rockers except that extra clearance might be needed. Are you talking about going to 1.6 stamped rockers or full roller rockers? I don't like stamped rockers because of the ball friction(hot oil) and side load they put on the valve guides; 1.6 would be even worse. If you are talking about going to 1.6 roller rockers with a roller tip, then my vote is yes!

John
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Old 10-17-2011, 01:06 PM   #40
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Quote:
Originally Posted by JohnRR View Post
Ravoll,
We haven't talked much about the 1.6 rockers except that extra clearance might be needed. Are you talking about going to 1.6 stamped rockers or full roller rockers? I don't like stamped rockers because of the ball friction(hot oil) and side load they put on the valve guides; 1.6 would be even worse. If you are talking about going to 1.6 roller rockers with a roller tip, then my vote is yes!

John
Thats the spirit.Thanks for your input.
Stamped steel with roller tips is what I had in mind.(CompCams part # RP1416-16).
Thing is I don't believe I can get roller rockers with polylocks under my stock valve covers.One solution would be to take stock covers and raise them just enough to clear the rockers,while leaving them stock.
Might even be able to buy some to the same effect???

Thing is, my vehicle has a historical registration and any visual changes from stock would cause questions,that would/could lead to a revocation.Then I'm in for about 3k a year tax and insurance alone just to drive it.
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