Yes, I understand this must be for most of you vetterans out there but I need help picking out a cam. Here's my future setup as I see it now:

Stock '77 L48 350 virgin block
Stock pistons and crankshaft
Edelbrock Performer RPM Heads- 64cc combustion 170cc intake
Edelbrock Performer RPM Air-Gap Intake
Holley 750 Carb (Vacuum Secondaries)

What I want is low end torque, and lots of it! The engine should very rarely see 5000 so I really want the power in the low end range-about 1500-4500. I also want a good solid sounding idle. I've done some homework and it looks like I'll be needing something with very short duration, but what kind of lift should I go after?

Here's one option I've been looking at... http://store.summitracing.com/partde...3&autoview=sku

 

It might be a beating horse question, but the same cam in different engines will run different.
Something with 110 lobe separation and no more than 274 duration due to a stock conveter, go with a 3000 stall and the sky is the limit!

 

I like your decision on a hyd roller. Thats a step too high for a basic 350 -- especially if you're looking for low end. 170cc heads may not take advantage of that cam. Do you have headers?

I think you'd be fine w/ .5 lift and less duration. Just my $.02

 

I like your future head choice but if your serious about best torque
1500-4500 RPM you need both a low duration cam and a smaller
then 750 cfm carb would be better at your low revs goal.
If you have your Q-jet the small front primaries it has would be a plus
for low end torque. if not go to a smaller 650 holley over the 750.

hydraulic roller
CRN-119821
.050 duration 214/222
adv. dur. 276/284
valve lift .488/509
LSA 112
comp. ratio advised 8.75 to 10.5

flat tappit hydraulic cam and lifters
# LUN-60101LK
.050 dur. 213/219
ADV. dur. 256/262
valve lift 454/468
LSA 112

mild cams to work in the rpm range you want, if you want
more lift on the flat tappit use 1.6 rockers.

 

That Lunati roller 243 at .050 intake duration is
worlds more cam then what you want, the 1600 to 5600 rpm
range it shows is a misprint. A cam like that in your 350 will
be a 3300/3500 on up cam.

Here is a simular cam in duration out of my Crane catalog
Hydraulic Roller
# CRN-119651
RPM range 3200-7000
.050 intake duration 240
.050 exhaust duration 248
valve lift int. .558
valve lift ex. .558
LSA 110

 

May you can stay with Edelbrock and install a Performer Plus camshaft.... quite good for torque!

....my opinion is you don't need Roller Hydraulic...... flat tappet systems are very reliables and at the rpm you will drive.... no problems!

A good move should be to install roller-rockers with 1.6 ratio..... some more lift is never bad!

 

Need more info, What trans do you have? What rear end ratio? Do you have headers and free flowing exhaust? When picking a low end torque cam with high compression you really need to check your DCR and also choose your cam to compliment your trans and rear end. A lower gear rear end will allow a lot bigger cam and still meet your goals. A manual also allows more duration and still be effective. Tougher to make a good recommendation until you provide this info.

I do kind of like this cam with 1.6 rockers but need the above info.
http://www.holley.com/50143.asp

 

Everything from the transmission back is stock, but I'm looking at upgrading to a 2004r or a Tremec 6-speed, depends on whether i decide to go auto or manual...

 

You will have stock dished L/48 pistons with aluminum heads
probably around 9.5 at best and aluminum heads you won't have
any problems with a mild cam.

 

Why bother with aluminum heads if his CR isn't going to be close to 10? Why not save a little dough and go with some Dart Iron Eagle 64cc heads?

 

I don't think that you can use that hydraulic roller cam without a retrofit kit on your '77 block. I would stick with a flat tappet hydraulic cam. For a good deal, check out the 1102 or 1103 cam from Summit.

 

You're right, he'll have to get the retro lifters because his block is not keyed for the newer lifters, but they work just fine. They do cost some extra $.

Hyd rollers are nice because you can get more lift and keep the duration down. Very streetable with nice performance. More vacuum, can be easier to tune at idle.

They have their downsides though. Its another moving part just waiting to explode at 5000rpms.

 

Here's a 383ci small block, camshaft advertised overlap reference chart, that is quite close in size to a 350, so you may find it somewhat helpful as a guide:

9* - 35* towing
26* - 52.5* ordinary street
44* - 65.5* street performance
61* - 78.5* street/strip
74* - 87* race
83* - 100* Pro race

This chart will give you a general point of reference to work with, as opposed to only guessing.

Here's how to calculate your advertised overlap:

Add your intake and exhaust advertised duration (duration at .050 will not give you the correct overlap)

Divide that answer by 4

Subtract the lobe seperation angle (LSA) from that answer

Multiply that answer by 2, and you have it!

From what you describe, it sounds like you are looking for performance from a cam that is in the towing or ordinary street category. The cam you are looking at on that link, works out to 78* advertised overlap, which from the chart above shows it to be at the top of the street/strip or lower portion of the race category. This cam is best suited for performance at a much higer rpm than you indicate you want. You might want to keep looking. Hope this helps

 

Dont waste your money on a summit cam. thay are old technology. get a comp extreme, crane z-cam, lunati voodoo, or isky cam.........they have modern ramp profiles and will make more power across the board. I would also suggest using an "edm" lifter. it has a small oil hole for the cam lobe. They are $99 for a set of 16. With todays oil it can only help longevity with the modern ramp rates. Usually for torque, not more than 275 degrees duration and use a 114 lobe seperation.

 

You don't need a cam. You need a new crank. Stroker is the only way to get what you are asking for IMHO.

-Mark.

 

Trust me I've thought about it, but I'm gonna need alot of info and someone with experience with stroking a 350....

 

This motor will have between 9.0 & 9.5:1 scr with stock cast dished pistons & any 64cc chamber ... it cannot successfully use a large cam & maintain desired low-end performance.

why bother with an expensive roller setup at all? ... not a thing wrong w/ summit cams ... dgruenke's are good suggestion.

and why not less expensive iron 64cc? ... or even good-used L98/ZZ4 Alum 58cc heads?

 

The whole cam swap thing is usualy about moving the torque away from the bottom end. That is how you make power by moving the torque peak higher in the RPM range. You can make a little bit more bottom end with a cam swap but not much.

I can apreciate the goal of making gobs of low end torque with a few parts changes but it would be a lot easier with a longer arm in there. There is always a crate stroker short block if you are unsure of your engine building skills. I know the budget is probably an issue but as they say... "speed costs money - how much torque do you want?".

-Mark.

 

I'd like to see about 400 ft/lbs as low RPM as I can have it.

 

The guy asks a cam question and you tell him to stroke his motor?

I think with your max compression looking around 9.5:1 you're gonna be hardpressed to get that 400#s though.