uncle sam decided to treat me well this year so I get to fix my truck finally.

oem replacements are out of the question because of the whole cracking thing (possibly why they need replacing) also because they cost almost the same as the performance ones.

I'm looking at a 1.5k allowance to reduce the chance of the wife blowing a head gasket.

what I need to know, are the "Iron ram heads a good deal/ base for future mods."http://www.hughesengines.com/Index/p...2&partid=25426


if so I guess the other questions I have are should I go 1.920 or 2.02 for an extra $175.
also since they require rockers should I go with 1.6 or 1.7 sharps.

the truck is pretty much stock except the exhaust and a superchips tuner, new tranny and a fixed plenum
and plans for the future include a mild cam,a fastman 52mm, and possibly an intake.

also im not sure if I need different pushrods or not since it has the same valve size as stock and since im not changing the cam yet.

any help or advice would be greatly appreciated

 

Its hard to build a well tuned engine in stages. You need to find the RPM band that you will be running in the most and build the engine based on that.

If you buy giant flowing heads and a big nasty cam, the power band is going to be too high for daily driving.

The differences between iron and aluminum heads are heat transfer and ease of porting, honestly, I would go with iron heads if its going on a working dd truck purley for longevity reasons.

The rocker ratio will depend on what cam you decid to go with, most aftermarket cams are designed to work with 1.6:1 rockers. by running 1.7s you could mess up the physics of the cam... but sometimes not.

No matter what you do, you will see power gains from any of these bolt-ons, but you will have to match everything to squeeze all the potetial power out of it.

I would suggest you call a reputable engine shop and explain to them what you want to do. They can help you decide what is TOO big or not big enough.

 

im looking at getting the ported hughes iron ram heads. since im that far down im looking into gettin a good towing camshaft that can be ground down to be used with my 1.7 hs rr. of course ill have to probably get the correct length pushrods....but before i buy anything, i think calling up hughes engines would be a good idea

 

im in the zone for this as well, because i think my head gaskets are going out, im thinking of goingwith the 2.02 heads, and a new camshaft, and 1.7's, but after reading the previous post, i might go with 1.6's

Get the loaded heads BTW

 

That's an old school way of thinking. In fact, todays CAD / CAM precision T-6, heat treated, aged and specifically blended for heads, this is no longer the case. In fact, Al will outlast cast iron heads that are built today because, iron castings are no longer age treated like they once were and, they work harden over time thus developing micro cracks. Years ago, all blocks and heads were aged and thermally treated over a period of time to time align the molecules in the metals and to ensure long life. This is the main reason motor builders search the globe for certain old engines. The blocks and heads are so desirable because of the processing that they used to perform on them.

Even Hughes Engines has control over their blocks now. They have a whole new process that's done at a very well known plant where, they cast and treat the block in order to prevent material fatigue related failures.

Due to major cuts, the industry, in general, no longer practices this and, as a result, cast iron parts are not as robust as they once were. There's all sorts of stresses and risers that are cast into parts now and, since it's not done like it was way back when, you end up with poor quality heads just like what Dodge Magnum heads are known for. Well known to be defective due to design and the afore mentioned. The Magnum heads are cast iron that was not aged, cast too thin, and, it work hardens to the point of becoming brittle and, over time, they develop cracks. Some report failure after 40K miles on those.

Due to change in manufacture over the years, Al is the preferred choice and, you can see this trend in new vehicles and replacement parts.

They are machined to remove stress and are treated to reduce material fatigue.

Hands down, I would go with Edlebrock Al heads- RPM performer series: 2.02s and Sharps: 1.6s as well.

After speaking with Hughes Engines, even they admitted that those are better than what they offer. Plus, with Al, your reducing weight. I would lighten up the load and go with Al heads.

It took me a while to change my opinion on Al because, I grew up knowing the issues with Al of the past and only knew iron to be the way to go. Now, after speaking with some material engineers and people that rebuild engines, everyone told me Al is the choice material to go with.

 

Get the best you can afford. Personally I would go with the Iron Rams with the 2.02 valves and the HS 1.7's, the more valve lift you have for a given duration the better (more area under the lift curve). Just make sure you don't run into valve spring binding issues (which if you buy them from Hughes shouldn't be a problem) of valve to piston interference. The Iron Rams don't have the same cracking issues that the originals do, plus they flow almost as good as the Edelbrocks for 1/2 the money. Another good cast head is the Indy Cylinder Head/RHS replacement head that is a little more money but still cheaper that the Edelbrock and flows just as well

 

This is good to know, my only thought would be head gaskets. With the heat-cycling being much more dramatic with a Al head, would that adversly effect a head gasket designed for an aluminum head, I honestly dont know.

 

I dont necessarily agree with this. If you have too much of an opening, you will kill port velocity and sacrifice low RPM torque. This would be ok if you want to spin the engine into the higher RPM to get power, but working trucks will live between 2000RPM and 4000RPM most of the time. Of course both of our statements will depend on the cam profile being used.

 

Iron heads are vastly superior to aluminum any day of the week as far as durability.The problem with aluminum is thermal expansion rate of roughly 2 to 1,which causes serious issues with the head gasket.The heads themselves are little different,except for weight and thermal conductivity.You can usually squeeze a point higher with aluminum.The biggest problem with oem cast iron engine parts are thin wall castings and in the magnums case induction hardening of only the valve seat area,which made them brittle.The OEMS make things light to save fuel and metal.The aftermarket has no such restrictions.Most aftermarket heads have thicker decks and better heat treating.Years ago people looked for seasoned castings because they were stablilized and in case of the older engines,weighed more..Todays cast iron aftermarket blocks and heads are superior in every respect to the best factory offerings.The reason oem's use aluminum is becuase of weight savings and the ability to run more compression.For a relativley stock engine,I would use iron heads with small valves,maybe backcutting the exhaust,with a little more cam.You keep the nice low end intact,get a little lope and have a durable motor thats enjoyable to drive.If your building a race motor that will spend its time at 3k plus,bigger valves will certainly make power and aluminum is much lighter.When you slow down the port velocity with bigger valves,you lose low end.The edelbrocks certainly have a wow factor,but from the sounds of your intended usage,not needed.I spend my time doing a lot of headgaskets nowadays,because aluminum motors are way harder on head gaskets than cast iron.

 

The thermal cycling is not bad at all really. The shear forces are actually not like they were way back when where, you had a massive difference between coefficient of expansion rates on the older, thinner type, cast Al heads.

That's what gave it a bad rap. The thinner the material, the faster the thermal dissipation rate thus, the contraction is faster with Al than Iron so, it would shear the hell out of the gasket sets.

That's way behind us in the past. Everything has changed. When we look at the past, and take note of what materials the gaskets were made out of and, to what extent they applied computer modeling, thermal testing, etc, it was crudely executed compared to todays standards.

Today, we've got modern thermoplastics that exceed former, compressed gaskets, we've got Al reinforced molded with polymers that we didn't have back then to, computer modeling to analyze thermal stresses and fatigue at the gasket interface.

The problem with old school design was the gasket interface was the root cause for failure- not due to the material type of the head so much, but, more due to leaks that caused the head to be overheated thus warping it and, coupled with the cheap *** casting that was too damn thin to begin with, all bets were off- you had a POS from the word GO. The main problem back then was the use of poor gaskets coupled with no one looking at the design of the gasket itself. Today, there's all sorts of gaskets that are designed to handle those forces with ease due to some smart people changing the gasket design along with making material changes.

The shear forces at the gasket interface are higher than when using cast iron heads on a cast iron block. There is no denying this, however, you simply use a different gasket that is intended for the application and this takes care of that issue. Shear deformation is generated between opposite surfaces of the cylinder head gasket, accompanied by excessively large strains generated in a core plate of the cylinder head gasket. So, to get around that, one must make a change in materials, design and the way we test to find a viable solution to this issue.

THe last thing you want to do is to slap on a set of Felpros that are designed to be used with cast iron- you'll end up with a failure because the wrong gasket was chosen- not because of using Al heads.

If you change fuels to say, alcohol, here, you should change your injectors out or at the very least, modify them to accommodate the change in fuel types or, your going to have to be constantly flushing the system to purge that fuel type out to prevent damage.

Alcohol ruins std-injectors very rapidly. YOu tell people about how it will kill their injectors and, they ignore the advice and next thing you know, they wonder why it no longer runs while scratching their heads while looking perplexed. Then, they blame it on crappy injectors or how running Alcohol is the problem when, the fact is, all they had to do was make the necessary change to run that type of fuel. It works just fine when you use the right materials in most cases.

CM