Guest Posted February 16, 2001 Share Posted February 16, 2001 Looking for advise on a cam and carb for my '70. At this time my engine is a stock '69 corvette 350 , 10:1 comp.and headers What I was considering was a Holley 600 double pumper and a Comp cams Magnum 270 cam I want the cam to have that real lopey sound . Does any one have any experience with this cam ? I don't want to go to radical. Also I considered vortec heads, any word on them? Link to comment Share on other sites More sharing options...
Chevymd350 Posted February 16, 2001 Share Posted February 16, 2001 I dont' know about the cam, but I would go with the Edelbrock 1406 electric choke 600 cfm carb. As for the vortecs, you would need a new intake because the bolt patterns are different between the vortecs and the standard pre-86 chevy bolts. They are great heads, though, for the money. I would get a set if I had the money; I believe Jim Pace Performance Parts has a deal where you get the heads, bolts, and your choice of 3 intakes (performer, performer RPM, and GM) and some other stuff for 600-700 bucks. Definitely a good deal, it has been heavily discussed on the monte carlo mailing list (monte-list.nu). Have a nice night ------------------ Matt Dwyer Link to comment Share on other sites More sharing options...
Guest Posted February 16, 2001 Share Posted February 16, 2001 Thanks Matt!! I would love to have as many members as possible tell what cam and carb set up they're running(no fiction please). Link to comment Share on other sites More sharing options...
Guest Posted February 16, 2001 Share Posted February 16, 2001 The cam that I am running is a summit 234 duration at .050 and 488 lift. As for the carb, I'm running a Carter AFB Competion series 625 cfm with electric choke. For the intake I'm running a Holley dual plane. Sometime in the future I'm going to get a Wiend Stealth intake and a Demon 750 carb. I think that the wiend and the Demon will allow me to use the potential of the cam and the head work. This cam and the Flowmaster dual exhaust and dynomax headers give off a sweet lopey sound. The sound I think you are looking for. ------------------ Stella 70 Monte Carlo Link to comment Share on other sites More sharing options...
Guest Posted February 17, 2001 Share Posted February 17, 2001 If you go with the vortech heads thats a great choice for the money. They have better flow than the old double hump performance heads from the sixties. as was said before here, you will need the proper intake for these heads and you will also need the proper rocker arms also. They were a little different style than the older rockers. I believe it has to do something with clearance, or alignment or somethin. As said earlier here Jim Pace will set you up with everything you'll need. as for the cam, I think it's a good selection. I'm not familiar with the specs of this cam but I put the 280 comp cam varable duration cam in my 400 s/b and it was awsome! Not alot of lobe, it had a 110 lobe seperation angle which toned it down. I think the only way you get more lobey idle is from lowering the angle which I believe puts you into a problem of vacuum problems and alot of other situations you would'nt want in a daily driver. See you loose power in lower rpms (idle for example) because of the valve overlap. This is also the case when you get to much duration. Thats the way I've understood it. Your power does'nt come in until the upper rpm range. I don't think you'll have that problem with the 270 comp cam though. The closer you get the lobe seperation angle say at 108, the closer the overlap. Thats the way I understand it. Now if someone else understands it different, let us know. But thats my take on it. Link to comment Share on other sites More sharing options...
Guest Posted February 17, 2001 Share Posted February 17, 2001 zz4 bottom end with GM performance roller cam, 214/221 duration(.488,.509 lift or about .518,.539 with the 1:6 crane roller rockers). I run a holley 750/780 vacuum secondary carb. Link to comment Share on other sites More sharing options...
Monte Posted February 17, 2001 Share Posted February 17, 2001 Comp makes a 270H magnum and a 270HR magnum. The H is a hydraulic, and the HR is a hydro roller. 270 refers to the advertised duration of both cams, but they have different lifts and the Hydro roller has a different ramping configuration than the flat tappet. Lets assume that you are looking at the 270H. That cam should give you what you want. I have never had that cam however most magnum series have a healthy sound. Its about as large as you want to go with having a stock stall converter and stock gears. Comp suggests a 3.55 or lower. It should work well from 1800 to about 6000 rpm and not effect power accessories. According to comp they also suggest headers and a 4bbl carb. Now about the sound. That great sound people want is effected by both duration and lobe separation angle. Duration can be defined as time measured in degrees of crankshaft rotation. The larger the duration number the longer the valve is open. So, 270 duration means the valve is open 270 degrees of the 360 degrees that the crank turns. The exhaust valve duration effects the sound the most. The larger the duration on the exhaust side the more lopey the car sounds. That is because the earlier the exhaust valve opens in the cycle the more the sound of combustion goes through the exhaust. However, having an exhaust valve open too early can also cause loss of cylinder pressure and loss of torque hurting performance. Lobe separation angle ( LSA ) is just that. It is the number of degrees separating the peak lift point of the intake lobe and exhaust lobe on the cam. So the smaller the number the closer the peak lift points are of the lobes. The closer together the peak lift points are, the more time that both the intake and exhaust valves are open at the same time. A 106 lobe separation cam has more overlap between the exhaust valve closing and the intake valve opening than a cam at say 112 LSA. Cams with a larger LSA ground into them help give you that snappy off idle performance because they build cylinder pressure at low rpm helping to make torque. While cams with say 104 LSA which are used in Nascar engines have that rough sound because of all that overlap and work great at high rpm. Cams with low LSA dont work well on the street for daily driving. So the comp 270H should work well. It has a LSA of 110 which is good for the street. The 270H has 470 lift intake and exhaust. As far as a carb goes, I'm a holley guy, check out part numbers 0-80783 (650 vacuum secondary), and 0-3310 (750 vacuum secondary), the 750 will work better with a performance type of head. Double pumpers are fun and give you that kick in the pants feeling while you stab it, but that doesnt mean the car will be any faster with it. Vacuum secondaries will be more dependable and only use as much fuel as the engine needs. As far as heads go check out Air Flow Research. They offer a great street head that is about the same money as the vortec. Good luck Monte. Link to comment Share on other sites More sharing options...
Andreas Posted February 17, 2001 Share Posted February 17, 2001 The original 350 in my Monte was hopped up with Edelbrock RPM Intake and Carb, headers and a Comp Cams Xtreme 262H (.462/.469). Was running nice with 3.73 gears, but not too lopey. The new 383 stroker engine has an ISKY hydraulic cam with .490/.510 lift, 274 Duration and 108 LSA. It gives a very nice lope and also runs great. I do not know if I would recommend this cam spec for a daily driven 350, however... ------------------ 71 Monte 383 "The Full Monty" 86 Monte LS ZZ4 "The Gray Mouse" Andreas' Monte Carlo Site Member NMCOA, FGMCC (Event Coordinator) --------------------------------------- "It ain't a car if it's not a Monte" Link to comment Share on other sites More sharing options...
Guest Posted February 17, 2001 Share Posted February 17, 2001 Thanks guys ... This is what a club is about!!!! Keep the info comming Link to comment Share on other sites More sharing options...
MeanMonte Posted February 19, 2001 Share Posted February 19, 2001 Im running the Extreme 262h in my 350 now it sounds good and runns god too, im also running a single plane edelbrock torquer intake with a 600vac holley, i dono how this setup performs yet really but i know it carries up to 5200 with no problems, it should carry up to 6k without loosing power but if your going to run a dual plane intake get something larger than a 600 i can use it case my whole carb gets drawn from as aposed to just half........ Link to comment Share on other sites More sharing options...
chuckash Posted March 28, 2001 Share Posted March 28, 2001 My 70 with sb 400 has about 10.5 compression ratio, with Dart Iron Eagle 72 cc chambers, 215 cc intake volume heads, a performer intake, 650 holley vac. secondaries, HEI, and comp cams extreme energy 268, 1.6:1 roller rockers, 3.73:1 w/ auburn carrier in the rear. It idles nicely, and will fry the tires (235 60's) from a standing start. When it hits second, the tires just keep spinning. Anyway, my recommendation is to call the cam manufacturer. You mention a lopey idle, but overcamming a car will kill performance on the street. Consider the useage, is it a street car or a drag strip car? Lots of variables go into a cam, advice from other members is good, but the manufacturers have the engineering expertise to back up their recommendations based on your needs. My brother in law with his 340 Cuda actualy changed cams because the one he had was too radicle for driving on the street. It sounded awsome, pulled real good on the top end (shifting at about 7000 rpm), but had to idle at about 1100 rpm and lousy vacuum. Good luck Link to comment Share on other sites More sharing options...
Guest Posted March 28, 2001 Share Posted March 28, 2001 I'm going to give you the best advice you could ask for in regards to cams. "Go buy the May issue of Chevy High Performance, they have a fantastic write up on cams, and how they work." When it comes to a camshaft....it all depends on what you want to use the for. There are a lot of variables that you have to look at. Hey Stella, How much stall do you have in your car???? I'll bet if you had at least 2,500 stall you could get those rear tires to break loose!!! Link to comment Share on other sites More sharing options...
Guest Posted March 28, 2001 Share Posted March 28, 2001 Thanx David, I have that May issue and it is a great article !!! Hey , I called Comp Cams a couple weeks ago...took awhile to get a live person but it was worth the wait. Chuck...The Comp Cams tech said that the Extreme cam line is not the cam for me because of over 9.75 compression. Said something about the cylinder pressure created by the profile should be used only on engines under 9.5 comp.ratio Here in Syracuse the snow keeps falling ...almost 200 inches this winter CAN'T WAIT MUCH LONGER TO GET THE MONTE OUT!!!!! Link to comment Share on other sites More sharing options...
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