Iron Vs. Aluminum, the Final say!

[Guest]

I was using small port (early) genIII heads. When asked I would say 1995 Skylark top end. In truth a couple of the top end parts came from the Skylark, while other parts didn't, just same generation and design of parts. To explain a little farther one head and the LIM came from the Skylark, one head from some other car, and the UIM came from somewhere else. The rest of the parts, who knows, I had so many small port top end parts at the time it was hard to keep track of exactly what engine I pulled the parts from.

Here is one of the last pictures of it:

[Superdave]

if you want to flow those iron heads, I'll send you a t/a performance cover for your 10 bolt with the heads if you want it.

it's also funny that you broke the 10 bolt, and the 327 that was in it before didn't...

Lol, sure.. why not.


and yah, i don't think the old owners took it to the strip much though. fat slicks and 10 bolt rear ends don't mix well.

[LZeppelin513]

I don't think Lou from fiero.nl is saying that the iron heads are better. His point is that for a Fiero (not any of the FWD cars) it makes sense because he thinks what he did was less work than a full engine swap. According to his dyno he is making decent numbers. A touch more HP than a stock 3400 and a bunch more TQ. I personally would never do it but it does seem to be a good option if you are starting with the Fiero, want 200 hp and a bunch of tq, and don't want to do a full engine swap.

[ericjon262]

I don't think Lou from fiero.nl is saying that the iron heads are better. His point is that for a Fiero (not any of the FWD cars) it makes sense because he thinks what he did was less work than a full engine swap. According to his dyno he is making decent numbers. A touch more HP than a stock 3400 and a bunch more TQ. I personally would never do it but it does seem to be a good option if you are starting with the Fiero, want 200 hp and a bunch of tq, and don't want to do a full engine swap.

yeah, but what he did was a full engine swap in my book, and more work than a fill swap at that...

[Superdave]

I bet he dyno'd in 2nd gear to get those torque numbers. Or his buddy was fudging the correction factors.



we'll never know the truth, at least in my videos you can hear me shift into 3rd and see a real sheet.

[ericjon262]

I bet he dyno'd in 2nd gear to get those torque numbers. Or his buddy was fudging the correction factors.



we'll never know the truth, at least in my videos you can hear me shift into 3rd and see a real sheet.

I was thinking the same thing...

[caffeine]

I'm still convinced that a full engine swap is easier than installing iron heads on an aluminum head block and doing enough mods to make the power back. Cheaper as well.

[LZeppelin513]

I bet he dyno'd in 2nd gear to get those torque numbers. Or his buddy was fudging the correction factors.



we'll never know the truth, at least in my videos you can hear me shift into 3rd and see a real sheet.

I wonder about that too. I would like to see a 1/4 mile run. But.. if the numbers are not fudged it is pretty impressive.

[LZeppelin513]

I'm still convinced that a full engine swap is easier than installing iron heads on an aluminum head block and doing enough mods to make the power back. Cheaper as well.

I agree but "easier" is subjective.
It is definitely more expensive to do it his way, but then we are comparing a rebuilt engine to a lightly used engine. Him and others may prefer the rebuilt engine. I much prefer one lightly used, than to let someone else rebuild it.

[34blazer]

Fiero.nl really isn't that great of a site, because it's self moderated, people offering real info frequently get boo'ed out as trolls, and that only leaves the people who think a smog 305 can put out 500 hp because their swap ran a sub 15 second pass...

HA i was speed banned after I offered up my opinion against the caddy 4.9 LOL.

[Guest]

I read the thread over there. What I find odd is that Lou talks about how his 3400 iron head is allowed to have higher compression, allowed to have ported heads, allowed to have headers, allowed to have roller rockers, allowed to have a full custom 2.5 inch exhaust, allowed to have an intake, and a custom tune

but

a 3400 aluminum head swap can't have any of that. He bags on a guy named Joshua reidl for what Josh claims is a stock 3400 swap. But Lou claims its not stock because a custom exhaust had to be made to put in the fiero. Yea no kidding, I guess a factory grand am exhaust wouldn't fit now would it? And a tune as well. Yea I guess you can't use a grand am computer as easily as a 7730 with a tune on it. yet josh's 3400 dynoed at 204 whp and lou is crying it made those numbers because it wasn't "stock"

Thats what I don't get about the whole argument. Lou's engine is modified a decent amount. Yet he wants to compare to stock 3400 and 3500 motors. All he talks about is the tq. I am sure his engine made that much torque with the stock 3400 roller cam, iron heads, and TPI style intake of the fiero. They are known to make good torque. That is because the heads and intake work best together to make low end tq. yet you notice his high end torque is awefull compared to the modded 3500 that made 275 whp.

Lou made like 180 hp and tq at about 5200 rpm. Dave was up around 270. Now lou talks about his new custom intake he is putting on. He is crazy if he thinks he is going to pick up 80 hp at 5200 rpm with that new intake he has.

Thats what I find funny about the whole thing. he won't even come close to an 80 hp gain with his intake. I wonder what excuse he will use for why the modded 3500 still made more power with only .1 more displacement, because Lou claims it can't be the heads.

[ericjon262]

my favorite part is that he won't answer this:

Originally posted by ericjon262:


LTx based heads have been proven performers for years, in fact, they've been that way since the beginning, they are hands down, no questions asked the best castings GM produced for a V8 with a 23*valve angle, and now you're bringing up LT1's, which has no basis for comparison on the subject as they had roller cams and aluminum heads from their onset.

When I asked about the roller cam V flat tappet L03, you refuse to answer, which confuses me, because you make the claim that the roller cam is where all of the improvement is on the GEN 3 motor, but yet these two otherwise identical motors don't have different outputs, and the only difference is the roller cam.

his argument is that the roller cam is the only improvement on the GEN 3 motor, so I show him the LO3 305 that was installed in 3rd generation F-bodies, and trucks, the trucks got a flat tappet cam, the cars got roller cams, but were otherwise identical. if there were an appreciable difference in power, GM would have marketed the camaro and firebirds with more power, it's easier to sell a car with 190 hp vs 170...

[Guest]

Why is it that people don't understand the mechanical advantage of using a lower gear than a 1:1 gear on a chassis dyno?

EVERY time I have seen a dyno print out from someone that used a gear that is not 1:1, the torque is high, but HP is low, this is EXACTLY the reason the transmission with multiple gear sets was invented, to give mechanical advantage, namely for acceleration.

I'm on another site where there are similar people, the ones that will challenge you to prove them wrong and then when you do, through proven math and empirical evidence, will then change the subject or say that the person proving them wrong just doesn't understand.

[Superdave]

He's also got DOHC pistons in his 3.4, assuming .040 headgaskets it's at 9.95:1 SCR (Also assuming the heads haven't been shaved or the block decked). With a stock cam no wonder it's making good torque. Still only around 170-180 HP though.


When we put together Clang's 3500 for his Z24 it made monster torque on the stock cam. SCR was around 11:1, ran fine on pump gas and was a blast to drive (when something else wasn't breaking on the car). 3500 with a ported top end, heads shaved .020 and .040 camaro gaskets.

[ericjon262]

Why is it that people don't understand the mechanical advantage of using a lower gear than a 1:1 gear on a chassis dyno?

EVERY time I have seen a dyno print out from someone that used a gear that is not 1:1, the torque is high, but HP is low, this is EXACTLY the reason the transmission with multiple gear sets was invented, to give mechanical advantage, namely for acceleration.

I'm on another site where there are similar people, the ones that will challenge you to prove them wrong and then when you do, through proven math and empirical evidence, will then change the subject or say that the person proving them wrong just doesn't understand.

I'm not sure on what goes on with a dyno, but if the dyno is seeing engine speed and roller speed, I imagine it could account for the difference.