Guest plainswolf Posted November 11, 2003 Share Posted November 11, 2003 I was wondering if anyone could check my power figures for an engine combination I am planning on for my 260. I'm planning on a healthy street build, but nothing too radical...my goal is a good 320-350HP at the flywheel within about 1000-6000RPM...if these engine combinations produce more than my goal HP...then LUCKY me! But again, I'm not looking for anything too radical as I don't want to full rollcage my car, but rather install new and full length frame rails/connect the entire frame with a few transverse members as well. also a rear X bar strut tower brace-(across the top of the struts and diagonally down from each top to the strut tower bottoms) and a triangulated front tower brace to the firewall(and perhaps down from the strut towers to the forward core support rails in front of the strut towers). I may also add a simple 4 point roll bar for added safety. Anyways, heres the combinations I plan on using as I am being given a 66-327and a t350 -(t350 which I will NOT use in favor of a 200r4). SBC 327. 4.030 bore X 3.25 stroke. Compression ratio - 9.0.1. Edelbrock performer RPM heads (2.02x1.60) -#60719* or-#60999* Edelbrock performer RPM airgap manifold - #7501* Holley avenger carb - 670cfm - Part #0-80670 Cranecams PowerMax H-272-2 Hydraulic, Dual Pattern #113941, Int./Exh: Adv. Dur. 272°/284° , Dur. @ .050†216°/228°. Lift: .454â€/.480†Compcams 265DEH #12-208-2, Int./Exh: Adv Dur. 265/269, @.050 211/221. Lift: .442"/.465" Compcams XE262 #12-238-2, Int./Exh: 262/270, @.050 218/224, Lift: 462"/469" And last but not least, short headers 1-5/8" into a Y and a single 2-1/2"-3" exhaust pipe with a good free-flowing muffler (but not looking for an overly loud car at all. I prefer the quieter but performance sound). Ok.. will I figure one, or all, of these combinations will allow me my HP goals with any of these combinations.. or will it? Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted November 11, 2003 Share Posted November 11, 2003 With that engine, those heads and intake and any mild cam or better should make those HP goals pretty comfortably. I think the 670CFM carb might be cutting it close though. You might want to check out a little larger carb so the breathing will be a bit easier. Quote Link to comment Share on other sites More sharing options...
Guest plainswolf Posted November 11, 2003 Share Posted November 11, 2003 DAM that was a fast reply! The one thing of all I was wondering about was carb... so I guess a 700-750 would be better. I'm just a bit nervous of over-carbing but it sounds like I may be under-carbing in this... hmmm.. Thank you! Quote Link to comment Share on other sites More sharing options...
Guest plainswolf Posted November 11, 2003 Share Posted November 11, 2003 I wish I had desktop dyno.. Quote Link to comment Share on other sites More sharing options...
Guest plainswolf Posted November 11, 2003 Share Posted November 11, 2003 I would also add that I want to go with the mildest cam profile I can(for best possible idle quality) that allows me to reach my goal HP. Thats why I like my second 2 choices of cam the best. Quote Link to comment Share on other sites More sharing options...
Guest Nic-Rebel450CA Posted November 11, 2003 Share Posted November 11, 2003 The 670 isnt really going to be under-carb, it will just be getting close to what the 670 is good for maximum. I would say that 670 is probably good to around 375 flywheel HP. Quote Link to comment Share on other sites More sharing options...
grumpyvette Posted November 11, 2003 Share Posted November 11, 2003 I would seriously suggest that you change the cam choice to a crane 113841 solid lifter cam, a 327 needs to breath in the mid rpm ranges, those other cams are too low in duration, Id also use the VORTEC chevy heads modified for a .550 lift springs and pocket ported, a shim head gasket of no more than .021 and no less than .016 to get the quench correct the vortec heads and cam are both cheaper and a better match to your goals (check clearances carefully on assembly as durring ANY cam install) be sure to get the proper matching intake,vortec valve covers and roller rockers all of which combined still cost less than the EDELBROCK heads and standard intake (especially if you can get the heads from a late model truck in a salvage yard and have the local machine shop install the good springs and do a valve/clearance job KEEP in mind your not locked into that 327, an intire vortec 350 engine from a salvage yard can sometimes be purchased from a late modle wreck for under $500 far less than just the cost of EDELBROCK heads http://sallee-chevrolet.com/Cylinder_Heads/Vortec.html the 327 and vortec heads make a good combo Quote Link to comment Share on other sites More sharing options...
Pyro Posted November 11, 2003 Share Posted November 11, 2003 I think Desktop Dyno over estimates HP most of the time. It is best to read stories in old chevy mags to get real hp numbers. I agree with grumpyvette. Vortec heads are the best bang for the buck. And I would also build a 350 over a 327 any day. The longer stroke makes a much better street engine with a wider torque curve. The cams you have choosen are on the edge of a smooth idle and a slightly rough idle. So good job there if you want to keep a good idle! If you do use the vortec heads, then get the cam that has more exhaust duration. Furthermore, I would avoid a solid cam if a loud valve train bothers you. I think you can build a 375 hp+ engine with 9.25:1 cr, 355cid, vortec heads, performer rpm air gap intake, holley 750 with vac secondaries, and a comp cam 265. And a little bowl work on those heads will get you another 25 hp. A 327 would make about the same HP as a 350 but the torque would be down at least 30 ft lb over the entire rpm range. I like your exhaust choice! I ran the same a few years back and really enjoyed the sound of a V8 running single 2.5 inch exhaust. Just make sure to get a smooth Y-pipe. Quote Link to comment Share on other sites More sharing options...
Guest plainswolf Posted November 11, 2003 Share Posted November 11, 2003 8) Quote Link to comment Share on other sites More sharing options...
Guest plainswolf Posted November 11, 2003 Share Posted November 11, 2003 THANKS for the info guys! Grumpy, I have sallee bookmarked... I like that site! Thanks! My main reason for using a 327 is that I am getting it for free, and the reason I want to go with aluminum heads and intake is for the weight factor. I'd rather spend my extra money on good lighter weight heads and intake than another engine entirely. Also, Im hoping the slightly lower torque of a 327 may help in not twisting my chassis with the re-enforcements I mentioned I have planned for it, which do not include a full rollcage. as for cam, I definitely don't want a solid roller but those grinds are impressive! (though I did flirt with the idea of the ZZ4 hydraulic roller setup) I decided on the single exhuat pipe after eading several related posts within here...(GOD I LOVE perusing all those old/new posts!) But I was unsure how those cam choices would affect power output and idle quality in a 327.. I don't mind a little lope to the idle, but don't want a choppy or real rough idle either. This will be not quite a daily driver, but fairly close enough. And I definitely don't want to run a real high stall converter in the tranny but a milder one instead. With all my combinations and figures I knew I'd be practically right on the money or better with a 350, but I am unsure of how it would affect the lesser 327. Desktop Dyno is not that accurate? I don't know much about it at all but have heard it was pretty close.. The engine and handling goals I have for my humble little 260Z is to create a hellaciously fun and simply outstanding little setup in my Z's power and handling. Not be the best in any individual category, but to be so dam good in so many different categories. Quote Link to comment Share on other sites More sharing options...
Guest Big Geek Posted November 12, 2003 Share Posted November 12, 2003 I just put together a motor for my neighbors 240-Z. It consists of the following parts. Vortec Heads. 1.6 Roller tip rockers. Compression is 9.65:1 Stock rods with ARP bolts. Stock crank. RPM Air-Gap Comp Cam 230@.050 Magnum 280-H (2000-6000 RPM) 1 5/8-in long tube Hookers. Holley 750-DP (Have not touched the jetting.) but did install jet extentions. Standard HEI Dist. w/an Accell coil pack. Total timing set at 35 degrees. As we have not tested the RWHP as of yet in this particular car this exact combo in my 68 Chevelle made 314-RWHP on the motor using a TH-350 and a B&M 2400-Holeshot convertor. It made 430-HP at the wheels on a 175-shot of N20 using a Super Power shot kit. This was done on pump gas with 3-degrees of timing pulled out when the button was depressed for the N20. Hope some of this helps. Cheers !!! Jim C. P.S.- You would lose some RWHP if using a TH-400 or an overdrive tranny but it should still be relatively close. Quote Link to comment Share on other sites More sharing options...
Guest Big Geek Posted November 12, 2003 Share Posted November 12, 2003 Oh one more thing. I may catch some flack for this but at the compression ratio you are talking about running you will make more power using an iron head but will trade off the weight factor. If you use an iron head I would HIGHLY reccomend using the Vortec head (Unported) as it had AWESOME low and mid flow lift numbers and it appears that is where you are wanting to make most of your power. Again I would use them unported as they respond poorly to porting unless you have a true proffesional or someone who really knows their stuff porting them. Cheers !!! Jim C. Quote Link to comment Share on other sites More sharing options...
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