but I did a search and found nothing really...Just want to discuss this with some fellow enthusiasts. Okay so we have been told that 18* heads perform better than 23* heads, and 15* better than 23* heads (given good port work and proper chambers on all aforementioned heads). Question #1...Why exactly are the lower degree (15,18*) heads better than the traditional 23* heads that come on the LT1, besides obvious greater port volume and smoother radii, what is the benefit? Is it because the spark or valves are at a better angle for combustion/ exhaust flow?

Question #2...How is it determined what an optimal valve angle on a specific motor? Like would a particular displacement or stroke or big/small bore motor run better with certain degree heads?

Question #3...Why are there no heads that are say 10*? I think there are 12* heads, not sure, but if so how come I never see them on max effort motors?

Question #4...Much like question #3 how come there are not heads that are say 25*, or 30*...is this a negative flow design or what?

Just a few questions for some thinkers out there like myself....Sorry if its confusing...

 

ttt. i'm curious too

 

Good question, only if i had the answer...

 

i think youve got the correct idea as far as flow characterstics and valve placement which can affect combustion chamber design. i also think that not every engine needs the same heads to make power. but since almost all american V8s are pretty much the same the heads that are out there fit whatever bill you need them to. a 10* head may not work well at all for these engines, but on a toyota Iforce it may. or maybe a ferrari V8 would prefer 30* heads. these things i do not know.

i believe there is a window for all engines and combination of these engines. if you go too big or you go too small your out of the window. i think the 15* and 18* heads fit the bill and are the window for a great deal of these SBC engines out there that need absolute max performance. if you need something else youve got to see if its availible or how much it will cost. for all we know a 16* head would be better in some instances.

couple things i think everyone should remember when building or modifying an engine. there is always more than one way to get the power you want. bigger is not always better. last but not least its about the total package. everything must work together and be correct. the people that have this last part down are the ones who build the baddest engines. they are the ones who know when to correctly use a 15* head versus an 18* head.