340 stroker 422

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More BS in post # 174 from Rat Bastid about comp ratio & alum heads. Must have an unlimited supply of BS.....
The engine masters episode said nothing of the sort about CR limits with alum heads, as claimed by RB. They tested an alum & iron head with the same 10.88 CR, & the alum head might have made 2-3 hp more, which is within the limits of dyno error. What is important is that they did NOT test CR limits for each head, by increasing CR until detonation occurred.
 
Bewy said:
More BS in post # 174 from Rat Bastid about comp ratio & alum heads. Must have an unlimited supply of BS.....
The engine masters episode said nothing of the sort about CR limits with alum heads, as claimed by RB. They tested an alum & iron head with the same 10.88 CR, & the alum head might have made 2-3 hp more, which is within the limits of dyno error. What is important is that they did NOT test CR limits for each head, by increasing CR until detonation occurred.
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Did you actually WATCH the show? Do you advocate how they ran the tests?

EM in FACT DID test the limits of both heads. Are you ever right about anything.



Those tests were no better than what NBC did with GM trucks.

Aluminum heads and cast iron heads can run the exact same compression ratio.

Unless you are an abusive driver like what EM did. At that point no head materiel will save you.
 
This is one of the things many of us will disagree on and we all have our thoughts. I know how I treat each build but that’s my deep secret.
 
I always thought aluminum heads absorb/remove heat from combustion chambers taxing the cooling system and allowing more compression? Luckily I can read the experts on here to educate and set me straight. As you were carry on with the bickering back and forth pictures of Vegas and stock 340s that could out run Hemis ect ect ect....
 
Bewy said:
More BS in post # 174 from Rat Bastid about comp ratio & alum heads. Must have an unlimited supply of BS.....
The engine masters episode said nothing of the sort about CR limits with alum heads, as claimed by RB. They tested an alum & iron head with the same 10.88 CR, & the alum head might have made 2-3 hp more, which is within the limits of dyno error. What is important is that they did NOT test CR limits for each head, by increasing CR until detonation occurred.
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Get your cooling system up to snuff. lol
Heat is a major factor contributing to detonation.
 
340sFastback said:
I always thought aluminum heads absorb/remove heat from combustion chambers taxing the cooling system and allowing more compression? Luckily I can read the experts on here to educate and set me straight. As you were carry on with the bickering back and forth pictures of Vegas and stock 340s that could out run Hemis ect ect ect....
Click to expand...


This has been discussed to DEATH but it still comes up. Here is the TRUTH about this crap.

When you are rolling down the road and you step down on the throttle and it rattles a bit you have what’s called “tip in“ detonation.

So, the rate of change of heat happens so fast that the aluminum can’t possible transfer the heat to the coolant fast enough. It just can’t. That rate of change is so fast the heat can’t get dumped into the coolant fast enough to reduce or control detonation.


The exact same thing occurs when you mash on it hard and get into rattle. The heat rise is so fast that there is no way the heat can get through the head, into the coolant and then control the heat to control detonation.

Now, if you want to watch the Engine Masters episode where they tested this they found no HP difference (they found 2 or 3 HP with one of the heads…I don’t remember if the aluminum head made more power or if the cast iron head made more power but at 2 or 3 HP…thats clearly in the margin of error as 10 degrees of oil temperature can cause that HP gain/loss) you will see what they do to say the aluminum head can dissipate heat better.


They laid on the engine to the point they heat saturated the engine and at that showed that the aluminum head got rid of heat quicker than cast iron.

And I called BULLSHIT on that as soon as I watched it. No one with the IQ of a potted plant would ever, in good conscience would do that to an engine.

That is the equivalent of pulling a 6% grade for 5 miles and NEVER downshifting. Who does that? No one.

Ao that part of the test is about worthless, unless you drive like an idiot.

Go watch the EM episode and see what they had to do to make the aluminum head LOOK like it can take more compression than an iron head. See if you would drive an engine like that.

I know I don’t.
 
Fishmen Post #180.
Could not agree more!!!
One of the reasons that alum can make more power is the superior heat shedding of alum allows for a cooler intake charge, which has more oxygen by weight because the air is denser. All else being equal, more HP.
 
Bewy said:
Fishmen Post #180.
Could not agree more!!!
One of the reasons that alum can make more power is the superior heat shedding of alum allows for a cooler intake charge, which has more oxygen by weight because the air is denser. All else being equal, more HP.
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Damn dude, you don’t think the rest of us KNOW to drop coolant temperature so you can run higher compression ratios?

I got hammered by several on here because “thermodynamics” says you make the engine less efficient with lower coolant temperatures.

The reality is cooler temps make MORE power every time and you get the benefit of being able to run higher compression ratios.

The materiel the head is made of has ZERO affect on what compression ratio you can run.

NONE.
 
jimmer said:
:popcorn:
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I just sat through that EM episode AGAIN. And it’s EXACTLY what I said it was.

It didn’t prove a damned thing let alone that an aluminum head can use more compression than an iron head. It can’t. Unless you absolutely abuse the engine.

If someone purposely abuses an engine like they did on EM they should do something else. Like play checkers or something.

Watch it for yourself. Would you run at peak torque at WOT for 1.5-2 minutes? I damn sure know I wouldn’t.
 
Hi, I have a few updates about how this thing turned out. I tried running this with less total advance on standard pump gas and effect was not good as you can see below ;-)
This was on 95 local which I believe is 91 American.

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We didn’t give up and ordered a set of cometic mls gaskets, victor intake and decided to run 100 octane gas.
The car is absolute animal. I spent some time tuning everything but it paid off very well.

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Also we got a new carb to finish this up.
Needed small jets change and accelerator pump tweak.

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Here is how she runs.





Overall car exceeds expectations power wise. I opened the rings a bit to be safe with some nitrous but this will wait…
 
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Newbomb Turk said:
What did your timing curve look like before and what is it now?
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Now its 1 blue and 1 lightest silver spring in the msd distributor, total 34 advance idle 18 deg advance (I made a custom bushing). I tried different mixes of advance and this one seems to be the best overall.
 
Miszny said:
Now its 1 blue and 1 lightest silver spring in the msd distributor, total 34 advance idle 18 deg advance (I made a custom bushing). I tried different mixes of advance and this one seems to be the best overall.
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At what rpm do you get full advance?? I forgot, did this engine go on a dyno??
 
Newbomb Turk said:
At what rpm do you get full advance?? I forgot, did this engine go on a dyno??
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Its all in around 3300 according to timing light. I never dynoed this one. Car will probably be on chasis dyno but I dont really know how to interpret the numbers with gear vendors on 727. What the impact of it is on the result. I go to the same place every time.

When I tried low octane fuel the advance was coming in much later and total was 30 degrees. It was all in at 4600 if I remember well. It didnt help much anyway. All it took was one hard hit.
 
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