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Bracket Talk Bracket Talk Forum Tech Talk - by Abruzzi 9* or 12* Cylinder Heads - What's your take?Go | New | Find | Notify | Tools | Reply | |
| 9* or 12* Cylinder Heads - What's your take? | Login/Join |
| DRR Trophy |
Just heard back from Mr. Stinnett that our other cylinder head is cracked. That makes it 2/2 after Dart ported them two seasons ago. The first cracked around 20 passes and the second is probably between 100-120. They are 11* Dart Big Chiefs, made good power but not sure I want to continue possibly risking a motor if one cracks as I'm going through the stripe. So what's the opinion on the 9* degree stuff out there now? I know APD is making great power but haven't heard much regarding the reliability. Or should I stick with a 11* and go with a different brand? MBE? Pro-Filer? Or something else? | ||
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DRR Sportsman |
Can you post them up. I would be curious where they are cracked at. | |||
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| DRR Trophy |
I don't have any pictures, but from what we've been told it's behind where the intake valve comes into the runner if that makes sense. The first crack wasn't visible to the eye but when they pressure tested it, in Stinnett's own words, that cylinder "had custom water injection". It locked up right before I flipped the ignition to go up for round 2. This second crack was visible but he doesn't think it was deep enough to leak any water. Dart attempted to fix the first head but couldn't get it fixed so we had a new head ported to match. Waiting to hear back from Dart/Stinnett about what to do with this second one. | |||
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| DRR Pro |
I’ve got a 9 degree 655 sitting in my shop that I have run the Dog Shyt out of with zero problems with the exceptions of a couple broke rockers.... | |||
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| DRR Trophy |
Take a look at MBE Facebook page he does a comparison between the 11 degree and the 9 degree heads. I ended going with the 9 degree head from him. | |||
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DRR S/Pro |
MBE stuff is definitely the top of the line from what I see. Watch any of his videos he's been making... Really nice heads no matter what they are... | |||
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DRR Trophy |
Are we talking bracket racing? TD/TS? Outlaw stuff? Other? That would possibly help to suggest something. Nick Craig 1971 Camaro Split Bumper 376ci LS3 | |||
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| DRR Trophy |
I've been watching his videos, definitely knows what he's talking about. Stinnett really likes his stuff, just seeing what everyone's opinion is. NC3x58 - SC/Bracket Racing primarily, and throw in some local top dragster/quick stuff. No desire or need to put any nitrous to it. Also to add, its a 615, with eventual plans to make a 632. | |||
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| DRR S/Pro |
What are you trying to do? How much power... Don't know of any issues with this head that you are experiencing so gonna say Dart should step up and correct the issues if they ported them too much or you got bad castings. If your at a point where you need new pistons then this would be the time to consider moving to the 9 degree heads but it will be more than just pistons to make the change, rockers, push rods and likely and intake also.... so if your good with what you got why change considering the additional dollars you will need to spend? BTW if your combo in in a door car, take a good look at your headers, the EX flange on the 11 degree darts sends the headers out at a different angle than every other head I have seen so you would likely have issues here also. Other heads, many are having good results with the 12 degree profilers and the Raptors. The 9 degree head is also very good! It really comes down to what you want to do! Just saw your post above, if just brackets and SC with some TD, I'd replace what you got! No brainer here... As for MBE, they do very good work but they also charge for it and then some IMO so for what your doing, not sure I would get a set for them unless your wallet is too heavy... | |||
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| DRR Trophy |
The goal is to always make more power, right?! lol but in general, we want something pretty reliable while also making good power. Stinnett mentioned this is the third set of heads with this specific porting that has had this issue so I would learn toward it being too aggressive of a porting compared to a casting issue, unless they changed the casting recently. To your point about pistons, not sure if we need them yet, when he called I don't think they had the entire motor apart so we're still waiting to hear back on that. But I agree that if it does need them, the now would be the time to change. We were considering changing the intake anyway, so that was already built into our budget but I agree, the rest of the valve train would need changing. And of course, this would happen right after we put a tool steel cam in. It's in a dragster, but we had a set of fabshop's built for the extended flanges when we bought the motor several years ago since we didn't have a set for the motor anyway. I had a steel 18* 632 that we put in my dad's car when we got the aluminum 11* 615, so he took the headers with it. Thanks for your response! | |||
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| DRR S/Pro |
My guess would be the leak is in the short turn section of the intake runner. Very hard to get in there to fix.... Have had the exact same experience with Brodix raised runner small block heads..... One leaked, they fixed it and it failed. Got a face full of water checking it for my buddy....!!! MBE is not going to be cheap for sure.... | |||
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| DRR S/Pro |
If your going to switch to the Brodix 9 degree heads, give Joe Jolley a call at Sunset Performance! You will get a great product for a reasonable cost. | |||
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| DRR Trophy |
SCDIV1 - That location sounds right. On the first head, Dart tried to fix and couldn't get it to hold so they warrantied a new head for us. We'll see what they're going to do with second one. Still waiting to hear back... TOP38 - thanks for the reference! | |||
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| DRR Sportsman |
Also you can look here. Three different head setups complete for about 10K with rockers. Overstock deal... https://www.shafiroff.com/Uncl...gines-And-Shorts.php | |||
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| DRR Trophy |
Heard back from Dart yesterday. They're going to try to get it fixed at no cost, and if they can't fix it, they'll sell us a head at a discount. From what it sounds like, the casting has changed since our heads were made. They've been running this port job on the "newer" heads and haven't had any issues so it sounds like the older casting just doesn't agree with the port they're doing. But it sounds like they wan't to get to the bottom why this is happening, so that is encouraging. | |||
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| DRR Sportsman |
Free would be better. Sounds like a "Nightmare on Elm street". You personally think it's just a porous cast and the port job finished them off? | |||
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| DRR Trophy |
Just curious, how fast and a what weight are you now? | |||
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| DRR Trophy |
1255 HP, 980 something torque, 4.10 gear, 1.80 planetary, 34.5 hoosier, 1890-1910 pounds, super comp style converter, best its been is 7.02 189. In SC trim went between 182-183. 60ft - 1.017 330 - 2.872 660 - 4.456 MPH - 154.46 1000 - 5.838 1320 - 7.025 MPH - 189.04 From the comparisons I've done, car should be faster than what it is... | |||
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| DRR Elite |
my next super comp engine will most likely have MBE/Brodix 9 degree heads. Around $16,000 assembled with T&D rockers and intake manifold. | |||
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| DRR S/Pro |
It looks like you're mostly asking about dart heads, but I'll tell ya, my 15 years old Profiler 12 degree heads on a motor roughly 80 cubic inches smaller (533") at the same weight as you, would drive away from these numbers. For some reason people tend to stick with Dart and Brodix and never look at profiler. I've had zero issues in 15+ years, they make more power then just about anything and when they came out, they were a decade ahead of the big name brands. .991 60' 4.36 @ 159 so far..... 6.86 @ 198 trying for more...... 533" single carb 235" Harrison 4-link | |||
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Bracket Talk Bracket Talk Forum Tech Talk - by Abruzzi 9* or 12* Cylinder Heads - What's your take?
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