Promaxx 320 flow numbers
01-13-2017, 08:24 PM
#31
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Do they have QC that stays at the foundry ? Reason why I ask is we all know what happens after all company reps leave the foundry / manufacturer / etc over there.
01-13-2017, 08:41 PM
#32
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I don't recall, but I believe they don't. That's why they are just rough cut. I also remember him saying that they changed the sand used in their castings. That is why they look so good in the casted areas that aren't machined. They quality of sand is some of the best.
01-14-2017, 08:06 AM
#34
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Interesting to see what Jim V. Does and what exactly needs to be changed on exhaust port if it is all done at .600". Interesting to see full out of box flow numbers.
01-14-2017, 08:54 AM
#35
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The new castings look great, I'm curious what Jim is going to be able to do with them. Here are some flow numbers for the Patriot 320 head. These were flowed with out a pipe on a 4.31 bore.
.20 140/103
.30 195/154
.40 252/189
.50 305/242
.60 343/256
.70 369/266
.80 363/266
.20 140/103
.30 195/154
.40 252/189
.50 305/242
.60 343/256
.70 369/266
.80 363/266
01-14-2017, 01:19 PM
#36
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I have these same heads on my 509. Ive only had the boat out once since the build so cant really say to much cause i was taking it easy and i need a bigger carb. My builder got the castings and built them up himself. Hes used them on several engines with no issues. I do lknow i am making way more power then before but its more then just the heads obviously. My builder ordered a custom ground cam based off the heads. Only time will tell i guess but so far so good.
01-14-2017, 03:45 PM
#37
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The new castings look great, I'm curious what Jim is going to be able to do with them. Here are some flow numbers for the Patriot 320 head. These were flowed with out a pipe on a 4.31 bore.
.20 140/103
.30 195/154
.40 252/189
.50 305/242
.60 343/256
.70 369/266
.80 363/266
.20 140/103
.30 195/154
.40 252/189
.50 305/242
.60 343/256
.70 369/266
.80 363/266
01-14-2017, 07:41 PM
#38
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Better cooling how?
They don`t handle more compression, they require more compression due to the faster absorbtion of heat.
Only advantage to Aluminum heads is weight saving, the rest is just marketing and old wives tales that came from great marketing.
You buy ready to bold on assembled heads all the specs are going to be tight for automotive use.May work just fine with tight valve guides and factory valve jobs, or it may not. Tim might be able to shed some light on that.
They don`t handle more compression, they require more compression due to the faster absorbtion of heat.
Only advantage to Aluminum heads is weight saving, the rest is just marketing and old wives tales that came from great marketing.
You buy ready to bold on assembled heads all the specs are going to be tight for automotive use.May work just fine with tight valve guides and factory valve jobs, or it may not. Tim might be able to shed some light on that.
Theres waaaaayyyy more to controlling what an engine can take before detonation, than simply cylinder head material. Its called , engine management.
A good example. Look at the 454 truck engines. For the longest time, thru the 70's, and 80's, and up till the mid 90's, the 454 truck engine, was 7.9:1 static, with iron heads. This engine was designed for 87 octane.
When GM revised it in 1996, they raised the compression to 9:1, still with iron heads, and ran on 87 octane. With the changes made, the power output also went up substantially as well. Then , they came out with the 8.1L engine, also 9:1 static. Again, 87 octane. Still, iron heads. The meat and potatoes pretty much remained the same.
Those engines certainly see some detonating types of conditions. Coolant temps in 210* range, lots of engine lugging pulling 15k lb trailers up a hill at low engine speeds, hot humid weather with insane underhood temperatures, and so on.
My opinion on the iron heads being handicapped, stem's from the days of guys running god awful lean fuel mixtures (had no widebands to help sort that out), thought locked timing was the best thing going, had no idea what heat range plug to run, and so on. They'd melt an engine down, and blame the material of the cylinder heads as the cause. When in reality, it was their tuning that was the issue.
01-14-2017, 07:55 PM
#39
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I also think there are some advantages just from the rigidity of cast iron, esp on engines running boost or nitrous. You have a cylinder head that expands at the same rate as the iron block they are bolted onto, the decks are extremely rigid , head "brinneling" is really not an issue, etc. When a thick iron head is clamped to the block with head studs, the clamping is excellent.
My old aluminum dart heads, had some sure signs of brinneling after 4 seasons of running. Not surprising, since I was running MLS gaskets with stainless wire fire rings. Felpro themselves admits that with an alumnim head, you will get some dents in the soft aluminum deck with those, as opposed to , a copper wire fire ring, that is softer.
My old aluminum dart heads, had some sure signs of brinneling after 4 seasons of running. Not surprising, since I was running MLS gaskets with stainless wire fire rings. Felpro themselves admits that with an alumnim head, you will get some dents in the soft aluminum deck with those, as opposed to , a copper wire fire ring, that is softer.
01-14-2017, 10:05 PM
#40
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Wonder what Merc uses for gaskets on most their engines these days. To be honest I can't see past a year or two tops with same builds. Like everyone else you always gotta take it to the next level. It will either be boat or engines. Just curious MT how much did you have to take off them to clean them back up. Maybe I can rig up some hot water heater elements to my heads and flip a switch 1/2 hour before a ride. Lol.
