[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.

[F-BIRD'88]

Your cr is already "higher" enough. The TFS 23° heads are a good choice. Make sure the assembled package has the springs/hardware capable of working with the camshaft you want to use.
The assembled packages are available in various progresssive K1 K2 K3 levels.
Don't be afraid to call TFS directly for tech advice, before you decide and order parts.

its a good idea to tear them down, inspect, measure critical lift clearances and thouroughtly clean the new heads before install.

You can build a very good high performance street engine around these heads.
The one issue downside with these heads is the angle sparkplug.

Really a pain in the butt with many headers. Make sure the headers you have or will buy will fit the angle plugs.

If its going to be a fitment issue, the cost of compatable headers that fit can easily exceed the cost of top of the line AFR street ready 195 Eliminators with straight plugs.
Sometimes a good deal is not the right deal.

[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)

[F-BIRD'88]

If the cr is 10.25:1 with a 63cc head the cr will be 10.14:1 with a 64cc head.

I would not go higher than 10.14:1 on your buildup with "91 octane gas". Here in Southern Ontario we have 94 octane gas which is a good bit better than 91. Using 94 octane I like to build for 10:1 to 10.6:1. I avoid excessive cr. No real net payoff.

So go easy on the cr with the 91 octane. If you build with a 62cc head @10.37:1 and it turns out to be a bit too much for your 91 octane gas (detonation, pinging) will you stop and remove the heads and correct the compression ratio before the thing comes unglued? or????
You are riding the edge with little or no cushion. Remember in (a all too short) time the engine will build up carbon in the combustion chambers which further raises the real cr and lowers the detonation resistance threshold.
The hot rod mags and dynamic cr/cam duration-overlap calc theorey pushers don't take this very real factor into consideration.
go easy on the enigne cr on a street motor.

The cam:

A good lil street hi perf cam good power and torque without getting too carried away.
Needs a bit of gear and converter for best results. Should work well for you.
1.6 rockers = good choice with this cam. Make sure the heads you get can handle the .510" net valve lift. I think you'll like it.
You may have to play with the push rod length. Read the direction for the heads.

[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]

Originally Posted by glen242

'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]

Originally Posted by elcaminodragster

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]

Originally Posted by elcaminodragster

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.