4 Valve Heads!
Thread Starter
Melting Slicks
Joined: Apr 2000
Posts: 3,341
Likes: 6
Drifting
Joined: Nov 2000
Posts: 1,477
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From: Florida 33460
Re: 4 Valve Heads! (45ACP)
Well these been out for a long time,but still never heard anyone who actually HAS one set in hes-her ride. Does anyone have anykind of comments or experiences(street miles???) about these heads?
Racer
Joined: May 2001
Posts: 304
Likes: 0
From: Bakersfield, California
Re: 4 Valve Heads! (bowtie racing)
What Id love to see is someone show some dyno sheets on a before/after basis..... Theres quite a few of us that run 350/383's with built motors making 450-500 horsepower on the motor with miniram/superram/carb.
The setup id like to see is a typical built l98: 383,miniram, afr 190, 58mm t/b, 1 3/4 longtube, 219 LPE or larger hydralic roller. And see before and after dyno results from afr 190's to these heads.
Id probably save up and go with a set if they could gaurentee 75 horsepower over the afr street 190's on my car. Can you a imagine a nice streetable 383 that makes 550-600 flywheel horse. Power would probably just keep climbing till you quit winding it with those heads. Sheesh..that would make for a mild motored 10 sec n/a daily driver if they make the power they claim. 9 sec 1/4's would be easily attainable in a very streetable miniram car with just a small 150 n20 shot.
The setup id like to see is a typical built l98: 383,miniram, afr 190, 58mm t/b, 1 3/4 longtube, 219 LPE or larger hydralic roller. And see before and after dyno results from afr 190's to these heads.
Id probably save up and go with a set if they could gaurentee 75 horsepower over the afr street 190's on my car. Can you a imagine a nice streetable 383 that makes 550-600 flywheel horse. Power would probably just keep climbing till you quit winding it with those heads. Sheesh..that would make for a mild motored 10 sec n/a daily driver if they make the power they claim. 9 sec 1/4's would be easily attainable in a very streetable miniram car with just a small 150 n20 shot.
Drifting
Joined: Jul 2000
Posts: 1,861
Likes: 1
From: Bremerton WA
St. Jude Donor '09
Re: 4 Valve Heads! (bowtie racing)
Theres a guy over on the CamaroZ28 board that has had some bad experience with them.
These things are like a bad penny :) (comment for Merle at dragnet)
Cory
These things are like a bad penny :) (comment for Merle at dragnet)
Cory
Drifting
Joined: May 2001
Posts: 1,329
Likes: 12
Re: 4 Valve Heads! (CHarris85Vette)
Yeah saw them before. They seem nice but don't mix them up with OHC heads...those won't let you go higher RPM. They will surely flow better than 2 valve heads but then again I wouldn't see the street use of those as you can get more than enough flow in 2 valve heads. Another thing to keep in mind is that they are huge and would probably make it very complicated to fit in a vette.
Thread Starter
Melting Slicks
Joined: Apr 2000
Posts: 3,341
Likes: 6
Well, my current engine (what amounts to a Performer RPM package set-up) has been
tucked between the fenders for almost ten years. Veeery nice street/weekend
warrior stuff, for sure, but . . . these heads actually have me thinking
about diving back under the hood.
If they perform as advertised, I can see going for it.
An LT5? An excellent engine, at least as far as I have heard, but . . .
. . . expensive (last I heard) to aquire
. . . not exactly growing on trees
. . . not a simple drop-in on a C3
. . . last I heard spare parts can be tough to come by
A Big Block? A far better choice (IMHO) than an LT5. But, as we all know . . .
. . . there is a weight penalty
. . . not cheap to mod (compared to sb)
I'll have to agree that it may make more sense to go the BB route, but *I* can't say for sure - I've never really looked into modding a BB all that closely.
In any event, I must confess that the idea of a truly high-winding small block appeals to me.
tucked between the fenders for almost ten years. Veeery nice street/weekend
warrior stuff, for sure, but . . . these heads actually have me thinking
about diving back under the hood.
If they perform as advertised, I can see going for it.
An LT5? An excellent engine, at least as far as I have heard, but . . .
. . . expensive (last I heard) to aquire
. . . not exactly growing on trees
. . . not a simple drop-in on a C3
. . . last I heard spare parts can be tough to come by
A Big Block? A far better choice (IMHO) than an LT5. But, as we all know . . .
. . . there is a weight penalty
. . . not cheap to mod (compared to sb)
I'll have to agree that it may make more sense to go the BB route, but *I* can't say for sure - I've never really looked into modding a BB all that closely.
In any event, I must confess that the idea of a truly high-winding small block appeals to me.
Racer
Joined: May 2001
Posts: 304
Likes: 0
From: Bakersfield, California
Re: 4 Valve Heads! (Lohkay)
"more than enough head flow in 2 valve heads" <---- completely wrong, the main limiting factor on making horsepower is the flow of the heads. These heads alone with the rest of the combination to go with it should be able to make a ton of HP. airflow is everything. Thats what a blower does right? just puts more CFM through at a given lift.
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Drifting
Joined: May 2001
Posts: 1,329
Likes: 12
Re: 4 Valve Heads! (CarbedC4)
Well humm...I know I'm not a pro in engines but I think my theory is right. And from my book, a blower increases velocity which is good. Increasing flow increases your volumetric efficiency but you will never get over 1.0 w/o a blower. so even if your heads flow more than your engine needs, it won't help its power...even reduce it in the low rpm range. Can someone acknowledge that? Or am I nuts? :)
Safety Car
Joined: Dec 2000
Posts: 3,767
Likes: 5
From: Jacksonville Fl
Re: 4 Valve Heads! (Lohkay)
Your nuts. Hi compression normally aspirated racing engines typically have a VE ratio exceeding 1.0. The theory to explain it is the tuning of the intake syste.
As for theory...well, the scientists at one time had told everyone that you will never exceed .707G's on a skid pad or on acceleration in the 1/4...which was disproven by people actually going WAY faster than that. New theories were developed in retrospect.
As for theory...well, the scientists at one time had told everyone that you will never exceed .707G's on a skid pad or on acceleration in the 1/4...which was disproven by people actually going WAY faster than that. New theories were developed in retrospect.
Safety Car
Joined: Dec 2000
Posts: 3,767
Likes: 5
From: Jacksonville Fl
Re: 4 Valve Heads! (dtorc4)
I was looking at the dyno sheets...looks like they make all kinds of high rpm power, but less low rpm power...or maybe even with the stock 1970ish LT1.
If I extrapolate this to modern times, I see they would make the same power with the L98 as L98 heads...maybe ported. Why? Because the low rpm torque is the same, and the L98 has a cam designed for nothing BUT low rpm torque.
If you put them on a miniram engine, with a hefty cam and custom prom programming, it will make more power.
So, my opinion is it's not going to be very great as a stock replacement on a TPI ( L98 ) engine.
If I extrapolate this to modern times, I see they would make the same power with the L98 as L98 heads...maybe ported. Why? Because the low rpm torque is the same, and the L98 has a cam designed for nothing BUT low rpm torque.
If you put them on a miniram engine, with a hefty cam and custom prom programming, it will make more power.
So, my opinion is it's not going to be very great as a stock replacement on a TPI ( L98 ) engine.
Racer
Joined: May 2001
Posts: 304
Likes: 0
From: Bakersfield, California
Re: 4 Valve Heads! (BBA)
Of course its a terrible idea for a low winding l98. L98 is not suited for drag racing or making real horsepower. Take stock l98 intake/cam and throw it in the trash unless you are towing.
If i take a typical street/strip solid roller .600 lift 406 SBC and swap a set of race ported 23 degree heads for the 4-valvers your going to pick up a ton of power on the low/mid and more on the top. arao 4-valve heads werent aimed at the 300 hp market. I bet i could build a pump gas killer 650 hp daily driver small block with those heads....do that with a normal 220-230 afr heads. But i also wouldnt spend the $5500 on 4-valve heads, id be buying other stuff with that 5500 (i could build 3 motors for 5500)
If i take a typical street/strip solid roller .600 lift 406 SBC and swap a set of race ported 23 degree heads for the 4-valvers your going to pick up a ton of power on the low/mid and more on the top. arao 4-valve heads werent aimed at the 300 hp market. I bet i could build a pump gas killer 650 hp daily driver small block with those heads....do that with a normal 220-230 afr heads. But i also wouldnt spend the $5500 on 4-valve heads, id be buying other stuff with that 5500 (i could build 3 motors for 5500)
Melting Slicks
Joined: Jul 2000
Posts: 2,112
Likes: 2
From: Peoria IL
Re: 4 Valve Heads! (CarbedC4)
For the price they are not worth it at all, AFR and Brodix's top 23* normal port and valve heads can flow enough for 600hp for less than half the price. A 23* Raised Runner head would be about even, and some good 18* heads would probably make more power. The RR's and 18* would run 2-3k add about a grand for fancy valvetrain parts required and you would still have about 2k left and the same or more power.
Drifting
Joined: Jul 2000
Posts: 1,861
Likes: 1
From: Bremerton WA
St. Jude Donor '09
Re: 4 Valve Heads! (korvetkeith)
Again... These heads are supposed to be a nightmare to get to work without spending cubic dollars. A 18 degree head would be a better option because you could get the heads used from a circle track guy and get them cleaned up and ready to go fairly inexpensively (cost is always relative), buy the shaft mount rockers for about $2000 or so, Get pistons to work with the heads (no additional cost over the pistons you would be buying anyway), And get custom exhaust fabricated.
A huge plus to this path is that it has been done before. Maybe this is boring to do the "same ol 18 degree head engine" but at the 600+ hp level I'd rather have it "boring" than blowing-up, dropping valves, or God-knows-what-else with the 4 valve heads.
At the same time, I'd love to see someone get these bastards running and have a set up that was actually reliable... someone with a lot of money!
Cory
A huge plus to this path is that it has been done before. Maybe this is boring to do the "same ol 18 degree head engine" but at the 600+ hp level I'd rather have it "boring" than blowing-up, dropping valves, or God-knows-what-else with the 4 valve heads.
At the same time, I'd love to see someone get these bastards running and have a set up that was actually reliable... someone with a lot of money!
Cory
Le Mans Master
Joined: Oct 2001
Posts: 5,302
Likes: 2
From: Atlanta GA
Re: 4 Valve Heads! (45ACP)
Still no reply from these guys. I was checking their website and saw the dyno charts. They didn't start the dyno graphs until like 3500 RPMs. The only time I see 3500 is getting onto the interstate. Otherwise, I don't normally go over 2200. Oh well... :( :cheers:
Le Mans Master
Joined: Feb 1999
Posts: 5,877
Likes: 1
From: Park Ridge IL
Re: 4 Valve Heads! (dtorc4)
It's pretty normal to start dyno runs at 3500 or even 4000 if you are trying to show peak hp/tq. Rarely do you see dyno runs done starting at 2000rpm. I wouldn't look at it as if they are trying to hide something, they are just showing what most of their potential customers want to see.
Le Mans Master
Joined: Oct 2001
Posts: 5,302
Likes: 2
From: Atlanta GA
Re: 4 Valve Heads! (korvetkeith)
I remember that for some reason that most dynos can't take measurements at those low rpms. You won't often see a dyno chart go below 3000 rpms.
Drifting
Joined: Oct 2001
Posts: 1,699
Likes: 1
From: Westampton NJ
Re: 4 Valve Heads! (dtorc4)
A friend (he owns a Mustang...:crazy:) and I built airflow files for DesktopDyno 2000 for the set of these for his 289 and my 350. My setup is producing about 430 HP (estimates from RWHP with a VeriCom)...and with the heads, about 600 HP NA. Oh, and it has >90% VE for the whole range of the enigine...and it continues to produce power all the way to 11,000 RPM...too bad I can't run that high.
His 289 was producing the same kinds of number increases. I'll get graphs soon...
Oh, and that equates to a 10.65 sec 1/4 mi at 6,000' (NA).
[Modified by rainman69, 8:00 AM 11/10/2001]
His 289 was producing the same kinds of number increases. I'll get graphs soon...
Oh, and that equates to a 10.65 sec 1/4 mi at 6,000' (NA).
[Modified by rainman69, 8:00 AM 11/10/2001]
