Cam selection for a 70's Malibu

[Christian Nelson]

Ok, now we're talking!

I have 3 pretty comparible cams to look at here, pretty close on the price on them too!

Driver 4r's suggestion

http://www.ebay.com/itm/Chevrolet-C...Parts_Accessories&hash=item4854dd006f&vxp=mtr

Summit setup hrpc suggested

http://www.summitracing.com/parts/sum-k1103/overview/make/chevrolet


268h
http://www.summitracing.com/parts/cca-69-246-4

THese all look like pretty good cams.

Now, looking at the durations, I've read that you want a bit more (10 degrees was mentioned) exhaust duration on the vortec heads.

Just how important is that?

Anyone see anything you wouldn't like about any of these three cams for this application?

 

[Christian Nelson]

I know how it is to be broke and need to work on ****, but sometimes you just can't skimp. Pushrods are $3 each. He can get by with buying the 2 or 3 that's bent, or if you guys have a Pull A Part, go spend a $1 to get in and snag a few in your back pocket. WTH, PAP isn't going to miss a few push rods when a dude is down on his luck and broke as hell. You now, if he's that broke, maybe he should just go to PAP, find a cleaner looking 350, and get the cam and lifters out of a motor and buy it at PAP. Just be sure to take 2 egg crates to mark the lifters so you can put the same lifter with the same lobes on the cam. SBC's don't commonly have a problem wiping out cam lobes. So a good used Cam with the same lifters on the same lobes will get him by and all he has to buy new is is the timing cover and intake gaskets. He can probably get cam and lifters for $20-$25 at PAP, snag a few push rods and get it up and running.

Unfort, the only pull a part places around here won't let you take cams out of engines. No internal engine parts sold individually, you buy the whole engine, or not at all. Same with tranny's rear ends, no pulling gears out, or axle's even. They say it's environmental, don't want to clean up oil spills. Not sure if pushrods are included in the list of internal engine part, but I suspect they are.

 

[HotRodPC]

Ok, now we're talking!

I have 3 pretty comparible cams to look at here, pretty close on the price on them too!

Driver 4r's suggestion

http://www.ebay.com/itm/Chevrolet-C...Parts_Accessories&hash=item4854dd006f&vxp=mtr

Summit setup hrpc suggested

http://www.summitracing.com/parts/sum-k1103/overview/make/chevrolet


268h
http://www.summitracing.com/parts/cca-69-246-4

THese all look like pretty good cams.

Now, looking at the durations, I've read that you want a bit more (10 degrees was mentioned) exhaust duration on the vortec heads.

Just how important is that?

Anyone see anything you wouldn't like about any of these three cams for this application?

It's actually been proven, multi pattern cams perform better, especially if you want to take advantage of bigger port runners. Not exactly sure how to explain that one other than it just works. If you see my choice #1, it is 10 degrees more on the exhausts and also 10 more on the lift, so it should be very well with the Vortec Heads.

 

[foamypirate]

It's actually been proven, multi pattern cams perform better, especially if you want to take advantage of bigger port runners. Not exactly sure how to explain that one other than it just works. If you see my choice #1, it is 10 degrees more on the exhausts and also 10 more on the lift, so it should be very well with the Vortec Heads.

Most heads don't flow nearly as well on the exhaust as they do on the intake, so the extra duration and lift on the exhaust side really helps make up for that.

 

[HotRodPC]

Unfort, the only pull a part places around here won't let you take cams out of engines. No internal engine parts sold individually, you buy the whole engine, or not at all. Same with tranny's rear ends, no pulling gears out, or axle's even. They say it's environmental, don't want to clean up oil spills. Not sure if pushrods are included in the list of internal engine part, but I suspect they are.

It's not environmental, it's greed. EPA requires all fluids to be drained before any vehicle gets set down for public use to pull parts so they can't drop fluids. Or maybe that's an OK thing, but it makes sense to me. Our PAP has the same rule on Transmissions but not anything else. Reason being, they can't sell the trans cores if they've been tore apart. You can buy an intake, or a set of heads, a crank, whatever you need from a motor. You can buy axles from a rear end, a 3rd member etc, but not transmissions.

Trust me, they won't miss a few pushrods. Pop a Valve Cover, slip a few in your back pocket and rock on. I sure wouldn't lose any sleep over that. If they weren't all out at my dads, I'd send you some pushrods.

 

[HotRodPC]

Most heads don't flow nearly as well on the exhaust as they do on the intake, so the extra duration and lift on the exhaust side really helps make up for that.

That and for some reason, I was thinking it helped with scavenging for some reason too. Honestly, I don't totally recall now. I just remember for sure, multi pattern cams have an advantage over single pattern cams.

 

[Christian Nelson]

Looks like the SUmmit one is your vote then, I think I wil reccomend that to him.

Thank you all for your help!

 

[Driver4r]

If it wasnt for the Lift(since we havnt found vortec max.). Ide still recamend the vette cam i linked.

In my truck with a 355(wore out), It smoked a 32" tire on pavement running on 7 cylinders, with a th350 and 3.08 gears.
The cam is PERFECT for low to mid range power.
The reason it only spun 1 is cause the 3.08 axle is open. But i was rolling forward and floored it and it broke loose.

When i first stuck in the 3.08 axle, i pulled 13mpg(roughly) mixed driving on 32" tires and a leaking cylinder.

 

[bucket]

I do believe that Summit cam is the one I have in my '70 Impala. I'm very impressed with it's powerband, and it has just enough lope at idle to sound good and let folks know it's not just an old grandma car.

 

[Driver4r]

I do believe that Summit cam is the one I have in my '70 Impala. I'm very impressed with it's powerband, and it has just enough lope at idle to sound good and let folks know it's not just an old grandma car.

Sounds can be deceiving LOL.