Sometime in the near future I want to junk my stock L81 heads & replace them with something that will give more power (current mods in sig.).
I've narrowed my choice of Heads down to the Edel Performer rpm, trickflow 23* or trickflow twisted wedge G2. AFR would be good but the cost is prohibitive. I was planning on 64cc chambers to up the CR.
So, what are the major differences between the 3 types of head above (particularly between the 2 types of TF)? Is any one particularly better than the others? I want a lot of mid range power, good economy(!!) & a bit more up at the top end would be nice :)
Has anybody got anything good/bad to say about my choices, or is there another type of Head for street use that I've missed?
TIA
Paul

 

You're lucky this is a C3 forum :yesnod: :lol: ;)

 

i dont know which head is the best ,but everyone seems fairly happy with the AFR heads. might want to just wait longer and get the best.

anyway i was going to say that if you put a thinner head gasket with the 64cc head you can make even more compression.

 

Paul,
I dont have anything to add to your post But I do love your sig pic :cool:

Stew

 

:nono: C'mon Paul.......the language isn't "that" much different across the pond! :D

:seeya

 

I'm sure I don't know just what you could mean! ;) Hope life's treating you well?

Stew: The building is Knebworth House, which is just north of London (the 1st & only time I saw Zeppelin was when they played in the grounds of the House). Just out of shot (front & rear) is a long queue of Vettes, which looked really :cool:

thejaf: :D

QuickVet: Thanks for the reply. I can get the Edel. heads here, but haven't seen any TF or AFR ones yet. Buying from the US invokes the wrath of UK customs, the tax + duty is a real killer (added to purchase price AND the shipping costs :mad ). If I go for the AFR heads then it would make sense to fly over & take them back as hand luggage (I'll have to convince the GF that she'd really enjoy a vacation to Summit Racing!).
How much thinner than stock are the thin head gaskets? Is it enough of a difference to cause any problems with sealing on the intake manifold, or is it small enough for the gaskets to take up the difference? I was figuring on aiming for 9.5:1 with alloy heads. 10:1 would be OK at the moment as we can get 98 octane fuel, but I've heard that the Government (or Big Brother, the EU) want to ban it.

What are the differences between the 2 types of TF head? And, just to show my ignorance, what's special with 23*? What's the standard angle? Can anybody explain the pros & cons of the various designs of Heads? And I promise I'll be more careful with my Post titles :)
:cheers:

 

My recommendation would be the ProTopline 180's for what you are looking for,a very high flowing head while maintaining excellent velocity.Even better price!

The are International as well. Email me if you cannot find them locally. I can find some for you in your area.
http://www.protopline.com

 

Seems to me the thinner style are a thin metal from (i think it was) felpro, that adds about .5 to the CR.. so if you had 9.5:1, you should see 10:1 with the new metal gasket alone. :smash:

 

HI Paul! So, you've caught the horsepower flu? :crazy: Plenty of good head around for you to have many choices. But keep in mind, the heads you select will only perform to their capabilities in conjunction with other components. Once you start....cam, headers, intake and carb is next. Otherwise it's a lesson in futility. All the big hi-performance head companies have web sites you can visit to compare flow numbers. I suggest you check their websites out and take notes. Summit and Jegs carry almost all the brands, so you can check pricing too. Good luck in your decision.
Eddie

 

To reply in a manner worry of the title, hopefully some of the engine studs will chime in.

In case you haven't checked out http://www.ryanscarpage.50megs.com/combos1.html so many powerful engine combos here. Find a combo similar to yours (cam, intake, carb, etc..) and see what they different heads they run with it to get max. power.

 

Just keep in mind that AFR's are CNC milled from the start. You would be comparing apples to oranges if you compared AFR heads to unworked Darts or Brodix (or other) heads. I believe Dart and Brodix also offer CNC heads now, so you would be better off comparing those to each other. Don't go too hog wild on your port size, your car will run like crap if the heads are mis-matched to the rest of the motor (ask me how I know :D ).

AC


[Modified by A C, 9:19 PM 8/2/2002]

 

I owned a set of TF Gen 1 heads that had numerous quality problems that resulted i broken springs and worn guides. After I had them repaired locally, they performed very well. TF refused to acknowledge a problem and did not warrant anything. So I wouldn't buy them again even though I understand that their quality problems have been resolved.
I visited the Edelbrock factory a couple of weeks back and was VERY impressed with the facility and the product. They do the complete package- design, casting, CNC machine, assembly, testing. If I was buying now, I'd certainly consider Edelbrock.

 

only problem with edelbrock is I believe they only have 170 intake runners vs others are around 190s. :cheers: I plan to save up for the AFRs myself.

 

The stock head gaskets on an 81 are the thin gaskets, also called shim gaskets.

 

Thanks for the replies.

Ben: I was considering (if I don't get any new heads for a while) just fitting the thinner gaskets to increase the CR. Would have been a bit :mad if I removed the heads to find that I already had thin ones fitted! So, thanks for the tip!!

flynhi: What sort of problems were there with the TFs & were they easy to sort out? Edel. are very popular here with SBs, but I'm wondering if that's because they are better than most or simply because they are easily obtainable?

Mountainmotor: Good info & thanks for the email (haven't replied as we have problems with our email server at the mo). I've just fitted 1.52 rockers & the Crane cam. I'm not after race car performance, just want to let the heads flow better (K&N & Performer on the intake, 2 1/2" duals with Monzas on exhaust) & get a decent CR. I want to have some heads that will work well with what I've got, but I don't want to find that they are too restrictive if I ever put a better cam in. I'm after more mid/top end power but not at the expense of losing my low end torque. The cam was chosen as it works well with the computer & gives good fuel economy. Apparently it's better than it looks as the valves are opened/closed very quickly to reduce overlap (& keep vacuum high for the ECU) but give good scavenging. It's a big improvement on the std cam (esp. now I've advanced my base timing) & economy is still v. good.
Am I correct in saying that small inlet runners (if well designed) give more torque & the larger inlet runners are more for top end power as needed when racing? As I'll probably never go above 5500rpm I just need a head that will work very well up to those rpms & will cope with any future "hot" street cam I may drop in.

AC: Good point. Mismatched heads & cams are exactly why I've posted this question. I've built 2 identical engines with high lift performance cams. My GFs has a big port/valve head & mine has a small port/valve head. The performance difference between the 2 is incredible. Mine feels restricted, as if it wants to go, but can't (apart from a very narrow rpm range where it does pick up). My Vette feels the same. It's hard to describe as it's just a "feel" & I reckon that changing the heads will make a huge difference, but I don't want to go too large on valve/ports (another guy has the same engine as above but cammed for the small port/valve head. He's put the large port/valve head on without changing the cams & it's killed the performance).

tominator: Good link - thanks.

Eddie: Hi! I can't shake that flu off :) There's far too many heads about which is what's causing me a headache! I'm trying to pick a head that will work well with the mild mods I've done, but will cope with any future mods. ie if I ever junk the computer & fit a bigger cam then I want to have some heads that will cope with it (changing a cam is easy, changing heads is $$$$). The only definate is that I'll never go for max power. One thing I must have is good fuel economy as fuel prices are just going to keep increasing. Take care.

:cheers:

 

How come their prices are so high? I thought New Zealand was a third world country, or at best, a second world country ;) . Prices should be cheaper!