QWKDTSN Posted August 20, 2001 Share Posted August 20, 2001 I'm a huge know-nothing when it comes to V8s (I'm learning!) First off, would this setup work with centerbolt heads (Corvette Vortec)? What's the deal with carbs, the idea I'm getting is that for a mild 350 a 650 carb is good for low/midrange and a 750 is good for high-end power. The motor I'm looking at has the aforementioned heads, roller cam, 4bolt main, and a windage tray, 10:1 compression, 300hp. The guy seems to be a competent builder and has satisfied customers. What I'm going to be doing is casual autocross, occasional drag racing, and a lot of bench racing I guess what I'm looking for is midrange, with solid torque and a top end that will pull past 6k. Ideally I'd get all that but I'm willing to make compromises since not all things are possible at this point. Also, where can I get a T-5 shifter on the cheap? Wrecking yard? Thanks. I've got my tranny, clutch and flywheel coming in in the next couple of days. I'm finally on my way and not just doing research! Oh yeah, sorry, here's the address. click [ August 20, 2001: Message edited by: Nion ] Quote Link to comment Share on other sites More sharing options...
Guest Locutus Posted August 20, 2001 Share Posted August 20, 2001 I can't tell by looking(others might) but you need to ask if that manifold will mate with Vortec heads. I do know that Vortec hads have different bolt patterns, but as to what else is different I am not sure. Quote Link to comment Share on other sites More sharing options...
dsommer Posted August 20, 2001 Share Posted August 20, 2001 I'm going to try to put this one to rest. I've got a set of 87 Corvette alum. heads and an Edelbrock Performer RPM intake. Hopefully tonight (or some time this week) I will bolt the intake to the heads and see what lines up and what does't. I've heard that the center intake bolt is different somehow. So I'll post later on my findings. Just wish I had the entire engine in the car. On a lighter note I just picked up a new set of roller (mech) lifters on e-bay for $138.50 not too bad IMO. Piece by piece I'll get it together someday... ds Quote Link to comment Share on other sites More sharing options...
Tim240z Posted August 20, 2001 Share Posted August 20, 2001 I am running the Vortec heads with an Edelbrock performer RPM intake manifold with a 750 mechanical secondaries double pumper on my 71 Chevy truck. The heads do require a special bolt pattern manifold (inlet) because the bolt anges are different and it has two bolts at each corner (none in the center between cylinders 3&5 and 4&6). I am very PLEASED with the performance of these heads which I bought new from Scoggin Dickey and they have the upgraded valve springs, but otherwise bone stock. I'm running the L82 corvette cam grind with some basic PAW headers. The heads cost me about $700 with shipping and are by far the 'best bang for the buck' on the market today. They outflow just about any head, except the very high end ones (more flow than the ZZ4 or LT1. I have the comparison flow numbers if anyone is interested. Obviously the valve covers are different because of the center bolt setup, but I got a pair of almost new stamped steel ones from my machine shop for nothing! The only reason I will not be using them on my V8 Z buildup is because I want Aluminum heads for the weight savings. Tim Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted August 20, 2001 Share Posted August 20, 2001 quote: Originally posted by dsommer: I'm going to try to put this one to rest. I've got a set of 87 Corvette alum. heads and an Edelbrock Performer RPM intake. Hopefully tonight (or some time this week) I will bolt the intake to the heads and see what lines up and what does't yes, documented lots, just a different angle on the centre bolt/just open yours up and you can still use your 'old' bolt pattern intake. I would NOT rec'd using 'old' intakes on Vortec heads as the ports do not match and although it appears to be a slight difference/altering for this too match greatly alters/inhibits their flow. It's been done and shown to fail. FWIW, unless you're really fond of the L98 heads you might get some decent dollar from the fbody crowd that would go a long ways to the vortec heads or world products for that $<600 price range...but then you need an intake...enjoy the game Quote Link to comment Share on other sites More sharing options...
dsommer Posted August 22, 2001 Share Posted August 22, 2001 Here's what I found. 87 Corvette heads casting #14101128 center bolt, aluminum. The Edelbrock performer RPM intake bolts right up not having to angle any thing or bore out holes on the intake. I'm happy, now I can get started on the port and polish job on them, and the suspension rebuild and the rearend swap and the ... ds Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted August 22, 2001 Share Posted August 22, 2001 Sounds great, I wonder if it was midyear that bolt angle changed? Are you doing your own port & polish? Wish I had those skills...big bucks around here to get that done right! Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted August 23, 2001 Share Posted August 23, 2001 The only thing that I personally think is out of the ordinary, and we've beat this to death, but I'll say it anyway.. If its a performer (and not a performer RPM) then I don't see the need for a 750cfm holley. A 600 or 650 would be fine. That said, if I got it for a good price, I'd probably do it. I've seen lots of deals on Ebay for older single plane manifolds (holley strip dominators, or used victor jr's for example)that I think I'm going to snap one up sometime for future Fuel Injection conversion. (I'd like to fab up a manifold, but not sure I've got the skill for that yet...) I've seen the regular manifold to vortec head conversion (conversion hell, its just redrilling the angle on a few bolt holes) and the only caviate that I've read is the sealing at the top (?) of the port can be a bit thin due to the raised ports. As Ross rightly said, enjoy the game indeed. Regards, Lone [ August 23, 2001: Message edited by: lonehdrider ] Quote Link to comment Share on other sites More sharing options...
dsommer Posted August 23, 2001 Share Posted August 23, 2001 Ross C I've never done a port and polish on heads before but I went and bought an air compressor and a grinder. I'm ordering a "kit" from Standard Abrasives through Summit and will go to work. I've read up on the job and it seems like it's not too bad just takes some time 10 to 12 hours is what SA advertises here is the address to if you would like to check it out. www.sa-motorsports.com Down load the DIY head porting guide and print it out read it and jump on in. It has lots of pictures and a video is even offered. Summit has the best price on the kit that I have found so far $38-40 I think is what I found there. Good luck, ds Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted August 23, 2001 Share Posted August 23, 2001 Thanks for the info DS. I've seen that info you rec'd and it is good. But having seen the results and effort of many around me who've tried I leave that to the pros for true results. Ported L98's (what you have) were outflowed by stock vortecs in a few tests now. Not to dishearten you, just a rather valid comparison. I'd double any hours someone estimates a pro type job such as that.....do play with your regulator pressure as it can really help you control your bits when working on a easily marred material such as your aluminum heads. Lone, I'm 100% with you on carb size. 600 edelbrocks have fed a lot of 400+hp small blocks. On the vortec/manifold conversion, it is only a small geometry difference b/t ports as you say but it's fundamental to the proper flow in those heads so yeah it works..but noticeable potential is lost. Also 100% on single plane intake with a hybridZ....and EFI is not needed IMO and IME. On my HEAVIER ZX the single plane victor jr. was great with the 600 edelbrock, ripped treads from 750rpm idle as usual. Now EFI'd I'm still enjoying the same intake design. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.