Brodix 18X heads??? - Page 2

Bob Verwold · 12-11-2008, 03:05 PM

After reading this and other posts, I'm wondering what's wrong with my motor! With posted HP running from 650-850 and my 421 is only making 596 HP at 6700 rpm, are the 18 deg heads worth that much of a difference? Or is it in the combo, motor was built by Ohio Crankshaft and I wasn't real pleased with that whole deal but that's water under the bridge.

63corvette · 12-11-2008, 03:33 PM

My 434 with the Brodix 23 degree heads that made almost 850 HP on the dyno was a 14.8 to 1 compression ratio. Comp Cams small base circle with almost .800 lift. (1.5 & 1.7 Ratio Rockers)
It made its HP from 5400 to 7200 RPM
It was all in the flow of the Heads and manifold that Ron's Porting Service did. He actually cut the heads to about 21 degrees.
They flowed 440 CFM and I had to use a worked Gary Stinnett 1050 Holley to get it to work. I started out with a 950 and that just was not enough. The engine would just labor. When I changed carbs it really came to life.
The car weighed 2435 with me in it and would run 8.70's at 155 to 160 at sea level.
My 2 Cents

H.A.A.C. Racing · 12-11-2008, 04:08 PM

Bob,

Without knowing what the heads flow, compression ratio, cam, etc. There is no way to tell why your motor is down on power, but one thing is for sure, that thing has to spin higher, if it is not making any power past 6700 there is your problem.

Bob Verwold · 12-11-2008, 04:46 PM

The heads are Dart pro 1 with 215 int runners, comp ratio is 14 to 1, the cam is the small base with a 679 /645 with the 4 and 7 swap intake is Dart with an 850 holley. I have been shifting at 6900 and going through the traps at 7100 to 7200. I'm still wondering if this carb is big enough?

The cam was supposed to be 5000 -7500...............Motor was new at the end of last year....

63corvette · 12-11-2008, 05:35 PM

I would look at the carb and check your valve springs.
If I noticed my 434 getting a little lazy I would look at the valve springs and usually they were a little weak.
When I tried to run the 950 carb my 434 would not hardly get to 7000 RPM.
My 2 Cents

R&S Motorsports · 12-12-2008, 01:13 AM

Well arrived at the PRI show today I will be talking to all of the manufactures and will post some results next week sometime, as far a carb I run a 1435 terminator with a O 1/2 pump on my small 396 which is very consistant and I was told that with the new combo and bigger heads that I may need the 2100 CFM model guess you can never have enough air the motor it will only use what it can take. When I was told that I needed the 1435 for the 396 I thought that the guy was nuts I figured that it was way to big for my combo but was way wrong when the car picked up almost 2 tenths and became much more consistant from a good 850 methanol carb.

rod butcher · 12-12-2008, 08:08 AM

Bob I sent you a pm
rod

sst3447 · 12-12-2008, 09:24 AM

I have a 434 with a set of Brodix 18c heads that are cnc machined and they are spreadport, titanium valves and t&d shaft rockers, 704 lift cam 14-1 compression with a 1050 carb with a dart block . It made 757 hp @ 7000rpm ,on the stop it goes 10.90 @140 in a 2950 lb car it was a big improvement over my 23 degree heads i had before when it went 10.90 @ 130with the same cubic inches was told i was undercamed my the machine shop it needs about 800 lift and would be over 800hp if i would change it but this combo is very consistant i would recommend Brodix and 18 degree heads to anyone that asks

Jason Oldfield · 12-13-2008, 11:30 PM

Quote:

Originally Posted by 63corvette

I would look at the carb and check your valve springs.
If I noticed my 434 getting a little lazy I would look at the valve springs and usually they were a little weak.
When I tried to run the 950 carb my 434 would not hardly get to 7000 RPM.
My 2 Cents

I picked up 30 hp on the dyno by increasing the size of my Race Demon RS from an 825 cfm version to 975 cfm. Every simulation I have run has shown that I should run as big of a carb as possible on my 383. This motor made 630 hp with a 4-7 swap cam and AFR 210 CNC ported heads. Nothing really exotic. I go through the traps at 7800 rpm.

Jeff Brandenburg · 12-19-2008, 04:32 PM

I have a set of 18X's on a 406 with a small .704/.704 277/284@.050 cam...motor made 681 on a really conservative dyno. Pushes our 2280lb Monza to a best 5.59's at 124mph using a 1050 Pro Systems gas carb

12-11-2008, 03:05 PM	#11
Bob Verwold Senior Member Join Date: Jul 2007 Location: Fayetteville Ohio Posts: 656 Likes: 0 Liked 0 Times in 0 Posts	Re: Brodix 18X heads??? After reading this and other posts, I'm wondering what's wrong with my motor! With posted HP running from 650-850 and my 421 is only making 596 HP at 6700 rpm, are the 18 deg heads worth that much of a difference? Or is it in the combo, motor was built by Ohio Crankshaft and I wasn't real pleased with that whole deal but that's water under the bridge.

12-11-2008, 03:33 PM	#12
63corvette Senior Member Join Date: Mar 2007 Location: Canyon, Tx Posts: 539 Likes: 122 Liked 299 Times in 91 Posts	Re: Brodix 18X heads??? My 434 with the Brodix 23 degree heads that made almost 850 HP on the dyno was a 14.8 to 1 compression ratio. Comp Cams small base circle with almost .800 lift. (1.5 & 1.7 Ratio Rockers) It made its HP from 5400 to 7200 RPM It was all in the flow of the Heads and manifold that Ron's Porting Service did. He actually cut the heads to about 21 degrees. They flowed 440 CFM and I had to use a worked Gary Stinnett 1050 Holley to get it to work. I started out with a 950 and that just was not enough. The engine would just labor. When I changed carbs it really came to life. The car weighed 2435 with me in it and would run 8.70's at 155 to 160 at sea level. My 2 Cents

12-11-2008, 04:08 PM	#13
H.A.A.C. Racing Member Join Date: Aug 2007 Posts: 319 Likes: 0 Liked 0 Times in 0 Posts	Re: Brodix 18X heads??? Bob, Without knowing what the heads flow, compression ratio, cam, etc. There is no way to tell why your motor is down on power, but one thing is for sure, that thing has to spin higher, if it is not making any power past 6700 there is your problem.

12-11-2008, 04:46 PM	#14
Bob Verwold Senior Member Join Date: Jul 2007 Location: Fayetteville Ohio Posts: 656 Likes: 0 Liked 0 Times in 0 Posts	Re: Brodix 18X heads??? The heads are Dart pro 1 with 215 int runners, comp ratio is 14 to 1, the cam is the small base with a 679 /645 with the 4 and 7 swap intake is Dart with an 850 holley. I have been shifting at 6900 and going through the traps at 7100 to 7200. I'm still wondering if this carb is big enough? The cam was supposed to be 5000 -7500...............Motor was new at the end of last year.... Last edited by Bob Verwold; 12-11-2008 at 06:00 PM. Reason: add on

12-11-2008, 05:35 PM	#15
63corvette Senior Member Join Date: Mar 2007 Location: Canyon, Tx Posts: 539 Likes: 122 Liked 299 Times in 91 Posts	Re: Brodix 18X heads??? I would look at the carb and check your valve springs. If I noticed my 434 getting a little lazy I would look at the valve springs and usually they were a little weak. When I tried to run the 950 carb my 434 would not hardly get to 7000 RPM. My 2 Cents

12-12-2008, 01:13 AM	#16
R&S Motorsports Junior Member Join Date: Oct 2008 Location: Wind Lake, WI Posts: 54 Likes: 0 Liked 0 Times in 0 Posts	Re: Brodix 18X heads??? Well arrived at the PRI show today I will be talking to all of the manufactures and will post some results next week sometime, as far a carb I run a 1435 terminator with a O 1/2 pump on my small 396 which is very consistant and I was told that with the new combo and bigger heads that I may need the 2100 CFM model guess you can never have enough air the motor it will only use what it can take. When I was told that I needed the 1435 for the 396 I thought that the guy was nuts I figured that it was way to big for my combo but was way wrong when the car picked up almost 2 tenths and became much more consistant from a good 850 methanol carb.

12-12-2008, 08:08 AM	#17
rod butcher Member Join Date: Dec 2005 Posts: 248 Likes: 292 Liked 129 Times in 24 Posts	Re: Brodix 18X heads??? Bob I sent you a pm rod

12-12-2008, 09:24 AM	#18
sst3447 Junior Member Join Date: Apr 2003 Location: erie ill Posts: 69 Likes: 0 Liked 0 Times in 0 Posts	Re: Brodix 18X heads??? I have a 434 with a set of Brodix 18c heads that are cnc machined and they are spreadport, titanium valves and t&d shaft rockers, 704 lift cam 14-1 compression with a 1050 carb with a dart block . It made 757 hp @ 7000rpm ,on the stop it goes 10.90 @140 in a 2950 lb car it was a big improvement over my 23 degree heads i had before when it went 10.90 @ 130with the same cubic inches was told i was undercamed my the machine shop it needs about 800 lift and would be over 800hp if i would change it but this combo is very consistant i would recommend Brodix and 18 degree heads to anyone that asks

12-19-2008, 04:32 PM	#20
Jeff Brandenburg Junior Member Join Date: Jan 2008 Posts: 3 Likes: 0 Liked 0 Times in 0 Posts	Re: Brodix 18X heads??? I have a set of 18X's on a 406 with a small .704/.704 277/284@.050 cam...motor made 681 on a really conservative dyno. Pushes our 2280lb Monza to a best 5.59's at 124mph using a 1050 Pro Systems gas carb