Aluminum heads worth it?

[wyrmrider]

how's it going
were those oprn or closed chamber heads?

 

[beanhead]

I just checked and the locators are still in place, only the shims were removed. I'm glad that was mentioned, because that hadnt even crossed my mind. Not sure if I need that much timing advance, but the motor really seems to respond well to it. Also not sure how accurate my aftermarket timing tab is, so it could actually be less.

If you aren't fully confident in your timing reading--getcha a piston stop(they're cheap). There's likely a yoo-toob video on how to determine your 'true' zero/TDC. It's easy and you'll know exactly where you're at..if you have trouble, search around here or let us know.

 

[roadrunner69440]

A lot of good points about cast and alu heads but the one thing that keeps coming back to me is detonation. this worries me because I am getting ready to pull the trigger on some stage IV pieces, ported and bigger valves, price seems right. Is detonation a never ending battle with cast heads? I'm starting with a clean slate as my block hasnt been prepped yet.

 

[rumblefish360]

Detonation is a fuel and timing issue. It also can be caused by a hot spot on the cylinder head causing ignition.

To avoid a hot spot on the head, with a Dremel or die grinder, break all the sharp edges off and smooth them out. That should do it easy for you. Many people also just go full tilt and smooth the entire chamber. The last step of coating the chamber is not normally done but another step possible saved for extreme cases of very high ratios and extreme environments like endurance racing.

 

[Guido]

First, I'm not a pro builder. Just a dude working out of his garage. And only rebuilt 10 motors in my entire life. I'm 52 now. I bought some 5093 heads -2 sets to be exact...The first set have valve tips that varied .036 in height. That was as far as I got with that set from Jegs. No need to inspect them any further. The 2nd Set was from Summit because Jegs had a 2 month waiting period. But I think both of those stores are about the same. The second set still had (one) valve tip @ .014 lower than the rest. The other head was perfect in that regard. So I decided to keep em' even though they still needed work before running them. I'll explain. The ports were very irregular and required a couple hours of porting work to clean them up to an acceptable state. And during the porting clean up I removed all the valves. It was then that I discovered the first of many lies from Edelbrock about the condition and parts used in these 5093 heads. 1st, only the exhaust valves are stainless steel, and the valves are just standard single plane grind seat. Ya know, like U'd find in any ordinary stock head. Not that its a bad thing for a mild build - My point is that Edelbrock lied about the parts and condition. But I had already tooled the ports and was now stuck with em'. So, I really started looking them over very carefully after that discovery - enlisting some tools and advice from my buddy who's a retired machinist. 2nd problem is that the springs are no where near strong enough for a .600 lift cam. They're barely strong enough to break-in the .488 lift cam I'm going to use. Last real problem and I'm probably forgetting something was that the 3 of the valves had small leaks and needed to be fixed as well. A few good things about these heads 1- they do have nice big fat valves and runners. 2- the retainers and keepers were all ok. 3- the guides were all nice and snug. Not too snug - just right. Oh yeah, I remember what else now, These heads cost me an extra $580 for roller rockers. Yes, the stock rockers would've been just fine but that one valve tip dropped lower than the rest really bugged me and I wanted it perfect. For all the hassle and extra money I would've just gone with some Promax heads that are fully CNC'd. But I think my buddy's probably right -no matter what u get - you should tear em' down and check them thoroughly. I'll try to post a few pics of my particular heads and what I encountered. Oh yeah, sorry one more thing that I hated these heads wont accept my tall valve covers with the long bolts that go through the cover top to bottom - why u ask? because Edelbrock drilled the valve cover bolt holes at the wrong angle. U can only use short bolt valve covers with these heads. That was the final slap in the face from Edelbrock. I can't use my beautiful $200 valve covers. Valve covers that fit my 906 and 516 heads perfectly. So I had to go with some old crappy Moroso chrome jobers. All rusty and ratty. 2 more hours of cleaning and painting them so they'd look half-way decent. Getting angry all over again. Sorry for the rant. Just my thoughts - good luck with your build.

 

[rumblefish360]

I grabbed a set of the Pro Maxx CNC’d small block head and disassembled it. Over all, very very good. A few ever so slightly tight valves brushed up with a quick bone of two passes and they were exactly like the rest. All valves sealed well. Same height.

Did machine the spring seat for Lunati solid roller springs. Very easy to do. Do so make sure you have a game spring height checker first before you machine or nominal corrections on your new springs and there height.