Sean 71 Posted May 25, 2009 Share Posted May 25, 2009 Hello I was wondering if any one has put a set of 18 degree heads on a 70-78 v-8 swap? If so what headers are you using? Did you have to run a header adapter? Thanks. Quote Link to comment Share on other sites More sharing options...
jt1 Posted May 25, 2009 Share Posted May 25, 2009 None of the "shelf" headers for a Z are big enough for 18 deg heads, you are looking at a set of customs to complement the heads. Also be aware you may need pistons cut for the valves, and a really nice rocker setup. Lots of power, but also lots of $$$$$$. jt Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted May 25, 2009 Share Posted May 25, 2009 Yes, Jap tin runs 18 degree heads. The stahl bolt pattern requires an adaptor plate. Custom headers will be required. Pistons for 18 degree heads also required due to valve size and spacing. Make alot of power! Quote Link to comment Share on other sites More sharing options...
jap tin Posted May 25, 2009 Share Posted May 25, 2009 The 18 degree heads that I run are Brodix 18X. They have the Brodix spread port exhaust patern. I used a Headman weld up kit to make the headers. What heads are you going to use? There are a couple of diffrent exhaust bolt designs out there. Quote Link to comment Share on other sites More sharing options...
Sean 71 Posted May 25, 2009 Author Share Posted May 25, 2009 I only have the block & the car right now, I was just doing some research before buying some heads, sounds like the 23 degree AFR's would save a lot of time, I love the flow #'s the 18 degrees produce. Thanks for your time & info. DR_hunt I was wondering when your next trip to Alb would be, I would love to take a look at your car if you don't mind. Quote Link to comment Share on other sites More sharing options...
jap tin Posted May 25, 2009 Share Posted May 25, 2009 Is it a bare block or a fitted block with crank, rods, and pistons ? It's easier to go 18 degree from the get go than to go 23 degree and then decide to go 18 degree later on. My engine is made out of stocking parts, the only thing custom was the cam that I had comp grind for me. Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted May 25, 2009 Share Posted May 25, 2009 (edited) Not real sure actually, but I'll let everyone know when. Really busy with work right now and both z's need alot of attention. Probably take the boys z this summer and try to click off a 9 second pass or two. Friend owns the track in El Paso and the altitude is lower there so we are wanting to head down there and try that one out. I think the cost of going 18 degree initially is higher but the advantage of bigger power is worth it for an all out car. Now that I have a tig the prospect of building headers is more practical than it was when we built the little z. I don't think it is a good idea for a street strip car. Edited May 25, 2009 by dr_hunt Quote Link to comment Share on other sites More sharing options...
Sean 71 Posted May 26, 2009 Author Share Posted May 26, 2009 Response to jap tin. I bought a Brodix aluminum block, I just got a large 327 billet crank, looking into rods & pistons right now, as well as heads. I just want to see what others have done & what kind of problems have been addressed. Response to DR. Hunt. I can understand wanting to go to a lower elevation. I would love to go 18 degree, I don't know much about them, other than offset lifters & rocker arms, I think there is a 2 piece intake which looks cool. However, I'm no welder so I will more than likely go with the 23 degree heads Thanks jap tin & Dr_Hunt. for all the info Quote Link to comment Share on other sites More sharing options...
jap tin Posted May 27, 2009 Share Posted May 27, 2009 With that short of a stroke and a non race deal you would be better off with a small runner 23 degree head. Quote Link to comment Share on other sites More sharing options...
Sean 71 Posted May 27, 2009 Author Share Posted May 27, 2009 Yes, with that short stroke and a NA motor for sure. I have been playing with many different combo's on the desk top dyno. I'm at the cross roads of how much power, NA or Turbo. The desk top dyno is very handy, however the turbo side is not as accurate as a NA motor. Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted May 27, 2009 Share Posted May 27, 2009 Very true about the desktop dyno IMO. I love the 3.25 stroke. If your going to use the 3.25 stroke, then if I were you I would try to achieve the 4.125 bore or larger and end up with 350+ cubic inches, go the 23 degree AFR head route, probably some 210's and some type of a solid lifter cam and single plane mainifold to utilize the rpm potential of the heads and stroke. With that short of a stroke you can easily use 6.2 inch long rods and with the right valvetrain can reliably spin it to 7500 every day. I'd try to keep the compression to 10:1 or in that neighborhood as I think you will find that it adds very little when compared to good flame travel when spinning it high rpm. Quote Link to comment Share on other sites More sharing options...
Sean 71 Posted May 28, 2009 Author Share Posted May 28, 2009 Funny you should say that, I was playing with 352 cubes just last week, with a solid roller cam, (thinking of the LS firing order) with 210 cc runners, however, I think I'm going to try EFI not sure yet. I like the RPM's (so does the combo) Quote Link to comment Share on other sites More sharing options...
bigbore468 Posted May 29, 2009 Share Posted May 29, 2009 Sean 71, dr_hunt gives excellent advice for engine build based on the 3.25" stroke crank. You probably know this combo is the little brother to the 377s that uses the 3.48" stroke crank and the 4.155" bore. Go with the largest piston size; with the brodix aluminum block, having a 4.155 bore should be no problem. Also, the long rods; 6"+ will be a good choice as it sounds like you will be buzzing this engine in the upper RPM range. This 348-352 engine will work great in a street driven Z; but if you are looking for all out performance, it's hard to beat the bigger cube engines. Never ran an aluminum block on a street car, but would assume it would have better cooling vs. a cast iron bow tie or 400 block. Good luck with your combo. Quote Link to comment Share on other sites More sharing options...
Sean 71 Posted May 31, 2009 Author Share Posted May 31, 2009 Thanks Bigbore 468. This will be my first aluminum block on the street / SCCA /strip. I'm somewhat familiar with the 377 & up to 434 motors. I'll be running a good size piston for sure. Yeah I'm wanting to see some RPM's especially with this light of a car. It should be fun. Quote Link to comment Share on other sites More sharing options...
rsicard Posted July 30, 2009 Share Posted July 30, 2009 dr_hunt: Find it VERY interesting to follow your threads on your new shop and build on your vehicles. These are the most interesting at this time when the economy is down. Can't even read articles about L6 engines as it appears that they have cooling system design faults. Unless these are dealt with the engine building block foundation is weak to begin with. Hope that you have more good threads regarding your shop and vehicles. Quote Link to comment Share on other sites More sharing options...
rsicard Posted July 30, 2009 Share Posted July 30, 2009 Sean 71: dr_hunt has some very good suggestions with the 6.2 rods. I am building a SBC 350 stroker and have SRP pistons for 6.0" rods that weigh in at 376 grams. That is lighter than most all similar pistons. With long rods, lightweight pistons and internally balanced assembly, the reciprocating weights come down and well as the rotating weights of these components yielding a quicker spin-up. Couple this with an aluminum flywheel and light weight balancer should yield a quicker spin-up. Quote Link to comment Share on other sites More sharing options...
Sean 71 Posted July 30, 2009 Author Share Posted July 30, 2009 rsicard I totally agree, I plan on saving as much weight as I can safely. I still want it to spin 8500 - 9000 rpm. ( not everyday) SRP & Mahle ( I really like the Mahle pistons ) make some pretty nice pistons. Internally balanced is the only way to go. (I M O) Quote Link to comment Share on other sites More sharing options...
rsicard Posted July 31, 2009 Share Posted July 31, 2009 Sean 71: Please do some more research into 18 versus 23 degree heads BEFORE purchasing any. The Mahle pistons as compared to the later model SRP are 25 grams heavier than the SRP. Scat has some great "H" beams rods. Another suggestion that I am utilizing is to ceramic coat the piston crowns, cylinder side of the valves, back side of exhaust valves and exhaust ports of the cylinder heads. Also moly coating the piston skirts and the back side of the intake valves to reduce carbon buildup. The ceramic will reduce heat from migrating through the piston, valves and from the exhaust port to the intake port keeping it cooler for the incoming charge. Just some suggestions. If there are any questions please do not hesitate to ask. Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted July 31, 2009 Share Posted July 31, 2009 There are two piston materials 4032 and 2618 I believe. Each has their plusses and minuses and applications. When choosing pistons make sure your getting the right one for your intended usage. Quote Link to comment Share on other sites More sharing options...
rsicard Posted July 31, 2009 Share Posted July 31, 2009 Again, Dr_hunt is right. The SRPs that I am using a 4032 alloy which has silicon blended into the forging. These have less expansion under heat than the 2618 which is STRONGER. This just makes me wonder if the 4032 can withstand the 8500-9000 RPM that Sean 71 wants to run. With ceramic coating they can better withstand the heat generated yet there is the lingering question whether the 2618 has more material in the crown than the 4032 wherein the 2618 is stronger by having more material in the crown? 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.