I would like to use aluminum heads on my Chev 383 stroker mainly because of better heat dissipation, less weight and possibly using lower octane gas (87 vs 91). However, I am not drag racing this car, so the lower weight is not a big issue. Also my compression ratio is 9.3 so I will still be able to use pump gas even if I have iron heads. I would like these heads to run a good long time without any problems and do not want aluminum heads if there are inherent problems with them. I have never used aluminum heads before and I am concerned about stuff like constant re-torqueing, stripped spark plug threads, difficult sealing on headers and intake manifolds, galled or seized threads, loose valve seats, etc. If you guys know about any problems like this or know which brands have the fewest problems, fill me in. I dont want to get them and then have all sorts of problems down the road. Thanks
Lotsa OEM stuff out there today with aluminum heads on iron blocks as well as on alum. blocks! I've got an '03 Chev Duramax diesel that has alum. heads with 100K engine warranty. Just use a good anti-seize on ANY bolt, and especially spark plugs and you'll have no problems as long as you don't boil the coolant! Dave
Use a GOOD brand of aluminum heads, use the ***ociated parts recommended by the head maker, and you will have none of the listed problems. (Keeping in mind that you should double check everything on them...just as you should pistons, rods, machine work, etc.) Use a generic or cheap brand like Pro Comp and your results may vary.
I ran a 383 SBC, with a set of Trick Flow Heads (low-rpm torque without sacrificing higher rpm horsepower) from Summit. Used ARP studs for head bolts, Fel Pro gaskets. Drove it like rental car. http://www.summitracing.com/parts/TFS-30400001/ http://www.summitracing.com/parts/ARP-134-3701/ http://www.summitracing.com/parts/FEL-7733PT2/ .
I put a lot of miles and spark plugs in motorcycles with an aluminum head. Nothing happened. Went through a couple of Jensen-Healy aluminum engines. Nothing exciting there. Been in Several Nissan aluminum head iron block engines. Looked fine. Seen Pontiac and Buick aluminum timing covers rotted away. Don't know the differance.
Just use studs instead of bolts where ever possible. And remember that everything built today has an aluminium head(s). Most have aluminium blocks as well. Cosmo
I've never had a problem with mine(Dart Pro 1) always put antisieze on the spark plugs. Put a set of Patriots on my newest engine (377 stroker) wish me luck!?!?
I've used a lot of aluminum heads. Use composition head gaskets (aka Fel Pro Permatorque and many other brands) and you will not need to retorque. I am not aware of any special need to retorque the head fasteners just due to the head being aluminum. Maybe, because aluminum expands more, it might be a decent idea but you don't have to retorque. Header bolts can be fun (uh, not really) with aluminum heads because you can cross thread them so easily. Be careful running the bolts in or use studs if that works in your situation. With modern, brand name aluminum heads I have not heard of anyone dropping a valve seat unless they overheat the head(s). In terms of sealing, there doesn't seem to be anymore difficulty sealing a header/manifold or intake manifold to an aluminum head compared to an iron head. Same procedures for sealing as far as I am concerned. Now here is a thought, with 9.3-1 compression, and little concern for weight loss, you may do well with iron Vortec heads unless center hold down valve covers will harsh the vibe of your engine. They have really good ports, combustion chambers and the center hold down valve covers leak less than the perimeter style. If you need more than .470 valve lift then buy the Vortecs from Scoggin ****ey and they are already modded for higher lift and they also mod them for older bolt pattern intake mannies.
Use good antifreeze and change it regularly, aluminum can corrode in a water only situation. Other than that, just be careful of running to hot, and you should have no problems.
A mechanic told me years ago to use Maxlox as an anti-seize it does'nt burn off like the grey stuff does. I use copper anti-seize
Consider EQ (Engine Quest) iron Vortec heads. They are nicely cast and come in both center bolt and perimeter bolt configurations. They also offer both new and old intake bolt patterns and are less money than GM's. Talk to HAMBER Mike Rogers at Rogers Performance; http://www.rogersperformance.com/EQ.htm
Off the top of my head, I would ***ume good brands would be Edelbrock and Dart. Do you agree and are there any others you would recommend? I have heard of some cast in china and then machined here, I would ***ume that would be a no-go.
Good suggestion, but I have an Edelbrock Pro-Flo system with a gen 1 intake manifold. If I got vortec heads I would have to get a new manifold, injectors and rails for about $950. So far the plan is to stick with gen 1 type heads. From what I have heard and read, there is a lot to choose from and they flow as good as vortec heads.
Ones that I have personally worked with and feel are good quality so far as their casting, seats, supplied valve train components (if any): Chevrolet; Pontiac; Buick; Brodix; TFS; Dart; World Products; AFR (Air Flow Research); and Edelbrock. There are a few others over the years, but it's not likely you would run into them as they are fairly esoteric. Now, whether any particular brand makes an appropriate head for your build is another story. For what you are doing, it's probably going to be hard to beat the Performer RPMs, for the price. So far as I know the Performer and Perf. RPMs are still cast and machined here. The E-Streets are supposedly cast elsewhere and machined here (which seems unlikely to me, since Edelbrock owns their own foundry); Edelbrock themselves says "manufactured in the USA". (shrug) I have not yet seen the E-Streets in person. The TFS Super23 heads are also in that price range, depending on componentry, and are nice heads for the buck.
I have a set of Broxix IK 200 on my 377 sbc in my '57 G***er. I have about 25 p***es and about 1500 miles on it so far and have had no issues. I did my research, spoke to sales reps at Dart and Brodix, and got what I needed. Aluminum heads just need a little more attention, that's all. Nothing to be frightened of or shy away from. Anti-seize, and careful when threading ANYTHING into them and you should be set. I studded my entire motor because I run it really hard and over engineer every motor I build. I would suggest studding the heads, ARP studs are well worth the money AND peace of mind. (use the ARP tightening lube recomended as well) Oh and use the gaskets recomended by the head manufacturer. (Head/Intake/Exaust/Valve Cover). Yes water will corrode aluminum over time so make sure you have plenty of ani-freeze in there at all times. Good Luck!
IF you can find a set of LT-1 heads, you can weld up the big water flow hole that doesn't line up with any holes on your Gen 1 block, surface the head, and redrill the water holes to match your block/gasket. Cheapest way to go if you are insisting on aluminum heads. The LT-1's were a bit queer 'cause Chevy engineers got the bright idea to reverse the flow through the system. Your intake manifold can then be slightly modified if you want, 'cause the manifold bolts are at and angle, but I've seen adapter kits the make the bolts work. I think you have to wallow out the holes in your intake. By the way, I have a set of LT-1 aluminum heads, unmodified, cleaned, un***embled. PM me if interested..
I just had this talk with my machinist as I'm switching out BB dart heads, and we got on the subject of SB aluminum heads (which I plan to do a swap on my SB powered CJ5). The two problems he's seen were: The cheap heads tended to be way off on header/exhaust mounting, he said it's been WAY off. Not every one mind you, but enough that he wouldn't recommend purchasing them. The second, and more common was running hotter. The explanation was that (on small block heads) was that the castings were thicker (to address strength concerns) therefore inhibiting flow. The solution was to run to byp*** lines from the back of the intake to a spacer block under the thermostat to make up for the lost flow. he didn't specify who's heads this was common on, but I took it to mean the cheaper stuff.....
So in general it sounds like all of you would recommend using Aluminum. the only "problems" you have mentioned is that you need a good brand (would do this anyway), be careful with threads (torque and seizing), studs should be used instead of bolts, and possible cooling problems caused by thicker castings etc. So with a little more attension to detail, they work just fine. So here is the reverse question, why do they even make iron heads anymore. I know Dart and GM still make them, and there must be others. I know the Dart iron eagle is about $280 less than the Pro-1 of the same exact description. Is cost the only reason? Someone told me that iron heads makes better power with the same compression ratio because it holds more heat and more heat is more power. The other comment is that it burns more evenly because of this. Is any of this true? If it is, I may want to use iron since I am using 9.3 CR.
Running in Jr. Fuel we are required to use iron heads. In my 383 SBC stret motor I bought World Products iron heads to have a nice no h***el almost stock engine.
Sort of, yes. Aluminum heads allow higher compression...or, another way to view things is that the AL heads require more compression to make the same power, all other things being equal. They usually are not. Holding heat in the chamber can certainly be a positive, if it's done correctly. Whether the burn is "more even" has more to do with chamber design and charge entry/swirl than with the casting material; all things being equal, and compression being equal, you won't see much if any difference in the burn rate. Depending on how you raise the compression and how much, you might see a difference as a result; for example, supposing you were forced to put a huge dome on the piston to gain compression, it might well cause issues. However, raising the compression ratio the few tenths of a point necessary to "equalize" the power between our two hypothetical engines isn't likely to require that sort of gonzo piston dome.
That is exactly what I am trying to build, a no h***le almost stock 383. I figure with a 212/218 duration roller cam, 9.3 CR, 2.02/1.60 valves and a decent set of brand name iron heads, it should easily make 400 HP. and that is about all I need.
Thanks for the explanation. When picked out the cam for this engine, the guy at Comp Cams said he would run no higher than 9.5 CR with this cam. Since that is my limitation, it looks like it would be best to run iron heads to make the most HP possible from the low CR.
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