[elcaminodragster]

well as some of you may know (if you remember me lol) i was going to build a 12 bolt for my elky then i couldnt because the cylinder heads need a lot of work (worn guides now bad springs) i might as well buy new heads. anyway its gone back and forth rear end or heads rear end or heads. im still trying to figure that out so im just shopping for both right now because they both need to be done asap.

anyways i have been looking at a set of RHS heads for 990 (a pair) but then i came across aluminum heads are only a 100 or 200 more (if i dont go all out performance that is) i came across a set of Trick Flow super23 heads for 1099

http://www.summitracing.com/parts/TFS-30400002/

i was wondering what you all could tell me about these heads. ive read they out flow many other heads of equal size. but i dont know what the "perks" are to the twisted wedge design.

and is it true with aluminum heads you can run .5 CR higher on the same octane gas and not risk denotation? and how much lighter are aluminum heads they cast iron?

this is my setup
383 10.25CR
currently 63cc iron heads cast #3947041
650cfm carb
268h cam
street fire HEI dist
victor water pump
rpm air gap intake
hooker comp headers
and i run 91 octane gas

 

[ericnova72]

First off, these are not "Twisted Wedge" heads, these are standard valve layout 23° heads. As far as outflowing everyone else's at the same size, only if you believe their marketing department . Nothing wrong with them though, they are quality pieces, just everybody has a flow claim over the next guy. They are pretty much equal to any quality as-cast head(Brodix, Edelbrock, Dart, RHS).

Yes aluminum allows a higher compression ratio on pump gas. Aluminums are 40 lbs or so lighter per pair IIRC.

 

[glen242]

I have been running TF 23*, 64cc heads on both my original 350 and now on my 383. The heads seem to perform well. Not saying there are not better performing heads out there, but I consider these top heads in their price range.

BTW, I am using Dynomax headers with the angle plug heads, without a problem.

 

[elcaminodragster]

so since my CR is 10.25 with 63cc heads my CR will rise to 10.37 i believe (correct me if im wrong) would i have any issues in doing that on 91 octane?


i have hooker comp headers and from looking at them i think the angled plugs would work best rather then straight because i have two problem plugs right now with them being straight.

this is how angled plugs are right???
intake side
\ / \ /
header side


i wasnt referring to the flow numbers that they list but many people on this site say they flow better then most of equal size.


and as far as the springs working with the cam this is the cam i plan on upgrading to so i believe it will work just fine.
http://www.summitracing.com/parts.aspx?sku=LUN-07101LK
with 1.6 full roller rockers (summit brand rockers btw)

 

[glen242]

Here is my 383 setup, FWIW.

Eagle crank, 12cc Speed Pro dish pistons, '0' decked block, TF 23* 64cc heads, 0.041 head gasket, CC XE274H cam.

Ignition timing is 34* all in by 2600 RPM + vacuum advance of 15* @ 13" vacuum.

I have been running this in my '76 'Vette 4 speed, for over two years without problems. Calculated static CR is 10.30, dynamic CR is 8.3. Using 89 octane BP since the engine was new.

 

[techinspector1]

'0' decked block, 0.041 head gasket

There's the answer.

 

[elcaminodragster]

what if i was to use a thicker gasket and still use the 62cc heads? i want to keep the high compression.

 

[ericnova72]

what if i was to use a thicker gasket and still use the 62cc heads? i want to keep the high compression.

The thicker gasket adds volume, so.... you end up offsetting any gain you got from the smaller chamber. Volume is volume, no matter if it is gasket or chamber or valve relief, it all adds up to volume at TDC.

Example: 64cc head and 8cc gasket is the same as 62cc head and 10cc gasket. They both add up to 72cc total.

 

[cobalt327]

what if i was to use a thicker gasket and still use the 62cc heads? i want to keep the high compression.

And, a thicker gasket will queer the piston to head quench measurement, which should be considered.