Guest Locutus Posted March 5, 2001 Share Posted March 5, 2001 I need some info on these heads, I am trying to decide if I want new heads(a very expensive option and I'm on a budget) or if they are worth port and polish and maybe soem larger valves if needed. I am shooting for 425-450 HP. They head casting number is 462624. They are either 1.94/1.50 w/76cc chambers, or 2.02/1.60 w/76cc chambers.(this is all I could find ont he web). Can anyone offer up any advice. I need to save some money some where to finish this project. Mike Quote Link to comment Share on other sites More sharing options...
Guest kc6wfs Posted March 5, 2001 Share Posted March 5, 2001 Those seem to be good heads. http://www.ammotorsports.com/chvheads.htm The specs com back as 1975-1986 350/400 76CC 2.02in 1.60ex I'd keep them and bump up compression via pistons. Dave ------------------ www.geocities.com/kc6wfs/240z.html www.NitroPhotos.com Quote Link to comment Share on other sites More sharing options...
383 240z Posted March 5, 2001 Share Posted March 5, 2001 These are not bad heads just look to see if they are "lightweight" castings (are the scallopped between the outer bolt holes) I would not recommend larger valves they would raise your powerband and would require a very expensive valve train to use it. For those on a tight budget I allways recomend the gm VORTEC heads they have the best flow of any stock head a great port velocity and are cheap about $450 for the pair and that includes the valves and springs you can get them from any chevy dealer and they come with a warrenty e-mail and I'll give you the part number I don't have it handy right now E-mail is rx7260Z@yahoo.com Quote Link to comment Share on other sites More sharing options...
Modern Motorsports Ltd Posted March 5, 2001 Share Posted March 5, 2001 Just keep in mind the limited lift on the vortec's before getting into offset keepers etc. You won't fit a 425hp cam on the vortecs without a good effort/$. If you're already buying all new valvetrain then that's OK. A friend just sold a couple Vortec sets with the right keepers/intake for a nice deal..too bad. I wouldn't put much $ into those large chamber heads you have for your power intentions, just my .02c. Keep your eyes out for a good used aluminum set that'll suit your expectations. You'll gain in a few arenas that way. Free hp from the extra compression/same octane w/ alum. and weight/out of the box flow of many etc. Quote Link to comment Share on other sites More sharing options...
Ray Posted March 5, 2001 Share Posted March 5, 2001 FYI... Modifying the Vortecs for a high lift cam can be done by any good machine shop cheep. 50 to 60 bucks and they will shorten the guides and machine them for PC seals. (Always cheeper to pay cash..) Now you may have to dissemble your heads to get it this cheep but if you are putting a real cam in a vortec motor you have to change the springs anyway.. If you have a drill press, the cutters and some time it can even be done at home. ------------------ Remember it is only a piece of metal. Quote Link to comment Share on other sites More sharing options...
Guest Locutus Posted March 6, 2001 Share Posted March 6, 2001 Ok the question still stands though, can I use these heads for the HP I want. I plan port and polish the heads(take my tpi intake with me) and possibly a roller setup. I am going to tear into the engine tonight to see what cam it has and play with the data in Desktop Dyno 2000, but I still want yall's opinion Mike Quote Link to comment Share on other sites More sharing options...
Guest Locutus Posted March 6, 2001 Share Posted March 6, 2001 Ok the question still stands though, can I use these heads for the HP I want. I plan port and polish the heads(take my tpi intake with me) and possibly a roller setup. I am going to tear into the engine tonight to see what cam it has and play with the data in Desktop Dyno 2000, but I still want yall's opinion Mike Quote Link to comment Share on other sites More sharing options...
383 240z Posted March 6, 2001 Share Posted March 6, 2001 Are you planning on builing a 350 or a 383? the only real restriction I see is the tpi they don't breath very well in stock form and the votech I had recommended will not fit your TPI base manifold so they are out. I've NEVER been able to rebuild a set of stock iron heads for much less than a new set of good heads would cost me. You can pick up a set of World products 200cc intake 64cc chamber heads that can breath 550hp for $795 fully loaded ready to go. Another option is the S/R torquers with 170cc intake and 64 cc chambers loaded that are good for about 475-490hp that run $749 not a bad deal when you figure the cost of screw in valve studs, a radius valve job, good valves, springs, retainers and locks. and these are brand new with at least 3 or 4 rebuild left in them! just my 2 cents. but for about 1 grand you can get a great set of Fast Burn heads from Chevy that let you bumb your compression to about10:1 now we build some POWER. ------------------ rx7260z@yahoo.com Speed Power Performance& Style. What else is there? Quote Link to comment Share on other sites More sharing options...
Guest Locutus Posted March 6, 2001 Share Posted March 6, 2001 The heads have a fresh rebuild on them, the engine was totaly rebuilt just before I bought the car, the only reasons I am even tearing into it, is to verify what I have, to make the upgrades to the power I want, and to make sure its going take the pounding I am going to give it. There is a local shop that will port and polish and do a valve job(note this does not include larger valves) with all new parts for about 300 for the pair. So that is why I am trying to decided if they are worth it or not. Quote Link to comment Share on other sites More sharing options...
Ray Posted March 7, 2001 Share Posted March 7, 2001 Look at the Sallee site for the head flow figures, the Vortec head flows almost as much as the Dart Sportsmans.... And yes they will work up to 400hp with little more than a spring change. The only problem is they don't take well to porting, mild cleanup ok but you will actually hurt the flow with a full on porting job.. and at 219 each (Scroggin and Dickey) they are a steal.... BTW 400hp in a 2500lb Datsun will run 11.'s and be very streetable... a 300hp motor with a 125hp spray kit will idle like a stocker and still run 11.'s (AKA RickB) name another car besides the Viper that can do that and be driven everyday.... ------------------ Remember it is only a piece of metal. Quote Link to comment Share on other sites More sharing options...
Guest Will Posted March 7, 2001 Share Posted March 7, 2001 425-450 HP on stock TPI hardware will not happen without at least a 100 shot. A stock TPI is good for about 350 HP before it becomes a flow restriction. www.tunedport.com has aftermarket TPI manifolds and runners, tunnel rams, etc. that flow more than stock, but may not fit your budget. Quote Link to comment Share on other sites More sharing options...
Ray Posted March 7, 2001 Share Posted March 7, 2001 Sorry I missed the TPI thing, Datsuns are light cars and TPI was designed to make Torque down low to move the 3500+lbs camaros and vetts... Will is right about the 350hp for a stock TPI and that is for a speed density with 22lb injectors.. To do it properly you would have to convert to a mini ram and get bigger injectors and the eprom flashed...Remember if you have ever driven a stock TPI car they fall on there face at about 4800rpm that is where the length of the runners limit the Hp. Now poeple have played with the runners and the base to improve it but you still have the same basic design and there lies the problem. As for the vortecs the intake is different and the ports are about 1/8 of an inch higher than a TPI manifold.. So to make them work with it you would have to redrill the bolt holes in the vortec head where the manifold attaches and then deal with the port alignment. It has been done by other people with some success but probibly isn't worth it. ------------------ Remember it is only a piece of metal. Quote Link to comment Share on other sites More sharing options...
Guest Locutus Posted March 8, 2001 Share Posted March 8, 2001 Well I do plan to upgrade the injectors, I also plan to burn my own chips, and do my own tuning as far as performance chips goes, that is the largest cost invovled in this project. I also plan to run nitrous for the track, but I still want close to 400 HP for the base engine. I have seen 400+ hp camaros and firebirds running the orginal TPI with mods to the injectors and eproms, and maybe bigger throttle bodies, but what do you think I can get if I run TPI with larger injectors and changes to the eproms, with these heads and a port/polish job, and a good perfomance cam,(not sure on numbers yet) and headers. I was told by the guy who built the engine it has TRW flat top forged pistons(not verified yet) but I don't know how to figure compression ratio Mike Quote Link to comment Share on other sites More sharing options...
Ray Posted March 8, 2001 Share Posted March 8, 2001 Talk to the TPI guys, most of them use smaller heads to maximize the ram effect of the TPI. I have heard of cases where porting the heads or using large port heads on TPI actually hurt performance.. but check with the experts, TPI has been out almost 15 years and alot of different combos have been used, When I had my Camaro I rode in several different TPI cars the best ones seem to use 383 or 400's with small 190cc heads and ported or aftermarket TPI units and big injetors. They all peaked at about 5k RPM. If you want 400hp and to use large or ported heads you may be better off buying a mini ram or building one out of an old tunnel ram...Look at some of the crate motors that are fuel injected and what some of the aftermarket guys have done most of them are more than willing to send you a spec sheet and a parts list. Most of them have done all the Dyno work and spent money to build a combination that works and the information is usually free...All you have to do is copy it... Take a look at the Scroggin and Dicky and the other dealers with a web site. They almost all do motor work and build motors for people and then Dyno them. If you poke them for the info they will give you the specs on what they have built and can build. Some of them will even fax or email you the Dyno printouts... BTW if you do get a chip burner let me know I am going to need a chip done done for my Blazer when I swap the TPI on to it, ------------------ Remember it is only a piece of metal. Quote Link to comment Share on other sites More sharing options...
Kevin Shasteen Posted March 8, 2001 Share Posted March 8, 2001 Dont forget Lingenfelter's book on modifying the SBC. In the back of his book he has about 10 dyno runs of engines that he has built. The last two were EFI-Emissions Legal SBC. One of them made 425hp while the other made 500hp-the second was built from the LT5 ZR-1 Vette engine. I think you'ld be more interested in the first. It used the LT1 from the Corvette/Camaro/Firebird. They have set ups for both an automatic & 6spd. He goes on to say that either package is available in the 350 or the 383 displacements. The trick to his set up for the Automatics was to use his SuperRam Intake; while the Standards got a Ported LT1 Intake. He said Motor Trend magazine tested both his set ups in F-cars & they achieved 13.10"s/113 mph on a humid/wet track. He believed that if the track were dry his cars would've seen the low 12's as his dyno's indicated 410RWHP. The 383 version was equipped w/SuperRam Intake & w/the 6-spd T-56 they acheived peak torque of 436ft.lbs @ 4500rpm's and 440hp @ 5500rpm's carrying that HP up thru to 6000rpm's. Lingenfelter used their own Hydraulic Cam with 219/219 Degrees Duration @ .050 & .503/.525 lift and 112 Lobe Seperation Angle. Retained the LT1 heads w/a CNC porting & fitted w/Stainless Steel Valves. Used JE pistons and a 4340 Steel Oliver Rods w/a steel 3.75 Stroker Crank. Hope that gives you some idea of what you need to get the perf.out of your car. You may wish to contact his Tech Dept & see what Specs they are willing to divulge! Kevin, (Yes,Still an Inliner) Quote Link to comment Share on other sites More sharing options...
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