Time to pick a cam ....

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340gordy

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.030 over 340
TRW forged flat tops, about 9.5:1 unless I tweak for more
Air Gap
750 Holley vacuum sec
ported X-heads (235cfm @ .050)
Manual brakes
727 w/3-3500 stall convertor
3.91 rear
Like to stay hydraulic and streetable but will see the track once or twice, may add 100 shot as well . It looks like the Comp and Lunati Voodoo 268's are highly recommended but I think I'd like a little more if my combo can handle it. Xe274 or equivalent ?
 
I will say the old standby,comp xe275hl or the next size up voodoo,the 3.91s and those heads should easily support it.
 
I would like to suggest the Purple Shaft 484 but I think other may prefer one of the Comp cams. What do you guys think about the Purple Shaft 484 or 509 with this combination (except with the addition of Eddy heads with cleaned up bowl areas and 10.5:1)?

I am more curious on everyone's take on the Purple Shafts vs the Comp cams.
 
Gordy the 268XE is actually a real mellow cam, the Voodoo a little more radical. The 274XE is a real nice street cam and I think it would do you fine. It's a nice thumpin cam but won't rattle all the screws loose in the car. You have enough comp., head flow, stall and gears to support it. I ran one in my 360 for awhile and liked it. I changed to a Voodoo 60404 (276/284) this last rebuild and didn't think it would be so much more radical but it is like night and day. The Voodoo series seem to be ground more aggressive than the Comp cams.
 
GTXperience said:
I am more curious on everyone's take on the Purple Shafts vs the Comp cams.
Click to expand...

The purple shaft cams are 20+ year old designs and can't compare with the fast ramp rate cams from Comp, Crane, Hughes or Lunati. One of the newer cams will have a lot less advertised duration for the same duration @ 0.050" and give you more lift too. This will give you better idle vacuum and low/mid range with the same or better top end.
 
I have almost the same motor in my '70 Dart Swinger; '72 340 .030 over, Keith Black pistons, compression is est. to be 10.2 to 10.5 to 1, stock X heads, stock crank turned 10/10, Performer RPM intake/Holley 700 carb, roller rockers, 904 with 3200 stall, 8 1/4 rear end with 355 gear....my cam is a Comp Cams 305/525...I think it's too much and it's actually slowing the car...I have had 2-3 people tell me I should switch to a Mopar purple 292/508 or 284/484...any suggestions??
 
The Lunati .494/.513 is an excellent cam,and will perform very well with your combo,i ran it last season in my stroker with great results.the mopar cams are ancient design,and should be left on the shelf...
 
Tnutz144 said:
I have almost the same motor in my '70 Dart Swinger; '72 340 .030 over, Keith Black pistons, compression is est. to be 10.2 to 10.5 to 1, stock X heads, stock crank turned 10/10, Performer RPM intake/Holley 700 carb, roller rockers, 904 with 3200 stall, 8 1/4 rear end with 355 gear....my cam is a Comp Cams 305/525...I think it's too much and it's actually slowing the car...I have had 2-3 people tell me I should switch to a Mopar purple 292/508 or 284/484...any suggestions??
Click to expand...

my 2 cents... not enough gear or converter for the 305H. I know a bunch of people running that cam and going 11's with it. They all run 4K+ verters. It's not a street friendly cam by an means.

I have a 305H on the shelf waiting to put it in something. :thumblef:
 
340gordy said:
.030 over 340
TRW forged flat tops, about 9.5:1 unless I tweak for more
Air Gap
750 Holley vacuum sec
ported X-heads (235cfm @ .050)
Manual brakes
727 w/3-3500 stall convertor
3.91 rear
Like to stay hydraulic and streetable but will see the track once or twice, may add 100 shot as well . It looks like the Comp and Lunati Voodoo 268's are highly recommended but I think I'd like a little more if my combo can handle it. Xe274 or equivalent ?
Click to expand...

Im assuming your peak flow is at .500 lift from the info above and thats the main reason I would get either the comp xe275hl or the lunati 60404 which has over .500 lift,this way you will take full advantage of your flow numbers,especially with 3.91s it would scream.If your running stock type rockers its even more of a reason to go with the bigger lift since actual lift will be less than whats advertised @1.5 from the cam specs.Ive ran alot of the xes in different engines and its hard to beat the xe274 for all around performance but the xe275hl is only slightly larger and gives you the added lift so its really close.I have no personal experience with voodoo cams but I wouldnt hesitate to run one,if you do a search theres a thread with some good info straight from the grinder himself.Theres alot of good suggestions here and I dont think you could go wrong with any of them but if it was mine I would run one of these two lol!.
 
GTXperience said:
I would like to suggest the Purple Shaft 484 but I think other may prefer one of the Comp cams. What do you guys think about the Purple Shaft 484 or 509 with this combination (except with the addition of Eddy heads with cleaned up bowl areas and 10.5:1)?

I am more curious on everyone's take on the Purple Shafts vs the Comp cams.
Click to expand...

In their day they were top notch and were very agrressive @.050 vs. their advertised duration especially when compared to comps,crowers and others.Todays modern dual pattern grinds are so much more broad on power and driveability that theres not much reason imo to run a purple shaft unless its cheap or the nostalgia.One thing thats interesting is the comp xe 274 specs @.050 are almost identical to the mopar 280 474 and that was a really good street/strip 340 cam.
 
I'll second (looks more like fourth or fifth actually) the XE274. How street friendly will the 275HL or Lunati 60404 be with his setup ?
 
When you start getting in excess of 235 @ .050 durations, the street manners begin to go away.

I'd stick with the 60403 Voodoo or the XE275hl (max) for street manners.
 
I've been trying to find out myself - all the articles I've read just mention the suppliers of the goodies ...
 
Call this guy. Jim..410-866-7660. He's forgotten more than most know, plus he will make the cam.

Its just a phone call away.
 
GTXperience said:
I am more curious on everyone's take on the Purple Shafts vs the Comp cams.
Click to expand...

dgc333 said:
The purple shaft cams are 20+ year old designs and can't compare with the fast ramp rate cams from Comp, Crane, Hughes or Lunati. One of the newer cams will have a lot less advertised duration for the same duration @ 0.050" and give you more lift too. This will give you better idle vacuum and low/mid range with the same or better top end.
Click to expand...

Agreed, except you must spec a fast ramp grind line or else your regular grind will not be as aggressive as a MoPar Purple cam. Though the Magnum cams from Comp Cams are just few degrees behind the Purple shafts w/ a equal or a tad less lift.

Though the word compare paints pictures of the cams being crap, this is not true. For your street ride, you could do better than a single pattern cam and one with a faster rise and more lift.
I've seen people run preety damn quick on a pure street single pattern grind cam.

To help you pick a cam by yourself, match the durations cruise to your car/driving style (Do note that more duration you have, theres a decrease in normal driving range RPM couple with a need for a higher gear ratio for best effect with said cam) and get as much lift as you can. (As in can use. No sense getting a lift over .550 if your head stalls or dips in flow @ .500)
 
a friend of mine talked me in to putting that 484 purple shaft in my 340 when I first built it,,,,,two months later when I pulled it out I went to the driveway and broke it into 4 seperate pieces. it fit in the trash can easier that way lol
 
Currently running a .508 Purple shaft and ol' skool Torker 340 intake. In my opinion I'd run a Voodoo 268, if I had the choice, but my cam runs good in my car. So it's not a "bad" choice, just maybe not the "ideal" choice...
 
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