Cylinder head dyno shoot out

Any interest in a dyno shoot out of a few popular SBM heads?

  • Yes

    Votes: 131 97.8%

  • No

    Votes: 3 2.2%
  • Total voters
    134
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Dart Frog said:
anyone approaching Max effort on a small block Mopar would never begin with a standard location push rod head would they?
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No. That's what I'm getting at.

I think it's been established that the test heads are "street" parts. Sure the line gets blurred to some degree but based on the above statement, it's generally accurate. TF designed their parts to fit into a certain segment of the market. It can be argued that was a good or bad decision but either way, their ultimate goal is profit. How many sets would they sell if they designed them to be used with offset rockers? Four?

So if that's the case, working the TFs to the point of being viable/competitive in a 'race' or 'max effort' application may not be the most practical endeavor. Can it be done? Of course. Is it worth it? That's up to the person doing the work or paying for it. At their core they are still replacement heads with inherent design flaws which makes them a dubious choice for a max effort build up. The guys running the test know and understand this.

The BPE heads are about as close to an offset rocker head as you can get without actually being an offset rocker head.
 
what makes people so scared of off set rockers? what is it?

nothing changes but the potential to make way more power.
 
9secRR said:
what makes people so scared of off set rockers? what is it?
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$$$
You're looking at about $1000 extra for a set of new offset W2/W5 rockers unless you can find something cheaper in the secondary market. For someone that is serious and wants the power potential, that's not a huge cost. For most others though, it's a "race" part that they don't need. Probably same folks that don't want a solid roller because you might have to check the rocker clearance once in a while. I regret selling the set of W2 rockers I acquired very reasonably, but I couldn't find a decent set of heads locally that could be inspected first. I don't "need" the W2 power potential but I'm not going to kick them out of bed for eating crackers either. Same reason I want to run an STR-12. Be different, have fun.
 
gzig5 said:
$$$
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Correct. Not sure on the H.S. or any other brands out there but Jesel rockers start at over $1,500 and their W2-specific ones are over $1,700. T&D rockers for the Indy 360-1-2 heads are over $1,800. I got my standard LA Hughes rocker arms for just under $1,000 about 10 years ago. They're around $1,100 now. In the scheme of things a couple hundred bucks is not that big of a deal but when you start looking at $800-$1,000 over standard rockers you take notice.

Problem is when you're stepping up to the offset rocker stuff, EVERYTHING goes up because you're theoretically beyond the point of using standard parts. It makes no sense to handicap an investment in those types of heads with low compression or low rpm or small headers, a small cam, a tight converter etc. so whatever it takes to support that level of power is going to cost more than just the offset rockers.

I went through that snowball scenario with my 416". The CNC ported iron RHS heads were good but of course I wanted more. Once I had the BPEs it became clear that pistons with a lake of a dish weren't doing me any favors so now it has 11:3:1 flat tops. The old 1 5/8" step headers are good pieces but kind of small so new, bigger headers. The BPE intake ports dwarf the gasket-matched Victor 340 so now has a port-matched Super Victor. Of course the cam is not going to cut it so from 251/259 @ .050" SFT to 263/268 @ .050" solid roller which means roller lifters, roller valve springs and good pushrods plus checking valve springs often... and on and on. It was an exponential hemorrhaging of money. Should have just gone this route to begin with.

IMG_6659.jpg
 
Yes I don't think it's that people are scared to go with W-2 style heads it's just all the accompanying cast. You'll need bigger headers with W2 pattern, W2 appropriate intake manifold, rockers, etc and by that time you're probably approaching the safe limits of a factory block possibly. I think a lot of people move to B or RB platform where it's actually less expensive per horsepower and and stronger architecture in the block, that's my take. But there's no denying the cool Factor of a badass W-2 small block.
 
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rmchrgr said:
Correct. Not sure on the H.S. or any other brands out there but Jesel rockers start at over $1,500 and their W2-specific ones are over $1,700. T&D rockers for the Indy 360-1-2 heads are over $1,800. I got my standard LA Hughes rocker arms for just under $1,000 about 10 years ago. They're around $1,100 now. In the scheme of things a couple hundred bucks is not that big of a deal but when you start looking at $800-$1,000 over standard rockers you take notice.

Problem is when you're stepping up to the offset rocker stuff, EVERYTHING goes up because you're theoretically beyond the point of using standard parts. It makes no sense to handicap an investment in those types of heads with low compression or low rpm or small headers, a small cam, a tight converter etc. so whatever it takes to support that level of power is going to cost more than just the offset rockers.

I went through that snowball scenario with my 416". The CNC ported iron RHS heads were good but of course I wanted more. Once I had the BPEs it became clear that pistons with a lake of a dish weren't doing me any favors so now it has 11:3:1 flat tops. The old 1 5/8" step headers are good pieces but kind of small so new, bigger headers. The BPE intake ports dwarf the gasket-matched Victor 340 so now has a port-matched Super Victor. Of course the cam is not going to cut it so from 251/259 @ .050" SFT to 263/268 @ .050" solid roller which means roller lifters, roller valve springs and good pushrods plus checking valve springs often... and on and on. It was an exponential hemorrhaging of money. Should have just gone this route to begin with.

View attachment 1716387710
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Knew a guy that raced a 12 sec car. Then an 11, then 10, then 9 sec car. Built a no-prep car (Mustang) that ran in the 4 sec 1/8 mile range. Told me he actually had more fun when he raced a 12 sec car as it was low/no maintenance, he could go to the track by himself instead of a cast of 4-5, current costs were out of control, etc, etc.

My takeaway was to be careful what you ask for! Hence my 11.0's sec avatar. (C'mon, gotta get a 10.99 out of it....I better be careful or I could be the next victim of the dreaded speed junkie slippery slope!!)
 
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Demonx2 said:
Knew a guy that raced a 12 sec car. Then an 11, then 10, then 9 sec car. Built a no-prep car (Mustang) that ran in the 4 sec 1/8 mile range. Told me he actually had more fun when he raced a 12 sec car as it was low/no maintenance, he could go to the track by himself instead of a cast of 4-5, current costs were out of control, etc, etc.

My takeaway was to be careful what you ask for! Hence my 11.0's sec avatar. (C'mon... gotta get a 10.99 out of it....!!)
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Seen that many times over the years. Everybody has a different threshold, but once your car starts giving you grey hair and headaches instead of enjoyment thats a good sign you've gone too far.
 
skrews said:
Seen that many times over the years. Everybody has a different threshold, but once your car starts giving you grey hair and headaches instead of enjoyment thats a good sign you've gone too far.
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Much more fun to try to go fast in a slow car, then to go slow in a fast car.

Best races I remember were slow cars such as 6 cylinder cars out of town. You could literally see every gaining foot as the cars reached certain shift points... LOL
 
gzig5 said:
$$$
You're looking at about $1000 extra for a set of new offset W2/W5 rockers unless you can find something cheaper in the secondary market. For someone that is serious and wants the power potential, that's not a huge cost. For most others though, it's a "race" part that they don't need. Probably same folks that don't want a solid roller because you might have to check the rocker clearance once in a while. I regret selling the set of W2 rockers I acquired very reasonably, but I couldn't find a decent set of heads locally that could be inspected first. I don't "need" the W2 power potential but I'm not going to kick them out of bed for eating crackers either. Same reason I want to run an STR-12. Be different, have fun.
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Don't forget the extra $ for the intake and headers on top of the rockers.
 
Yeah the speed monkeys never satisfied.. don't you monkey with the monkey. Just one more bottle of nitrous man you know I'm good for it LOL
 
there are speed parts and there is crack.

They both are very addictive,
 
Dad told me when I first got my car that there will always be someone with a nicer faster car than you. Build what you enjoy and leave it at that. That wisdom has kept me out of going full stupid. But it’s also kept my car with a 318 lol
 
Pile of parts heading to Concord, NC today. Wife is not real happy about dirty/nasty car parts in her clean car.

IMG_3486.jpg
 
This is why Chrysler guys are always picking **** with the chickens.

The cost of W2 rockers is essentially the same as straight rockers.

Harlan Sharp W2 rockers are almost the same price as the standard rockers.

Jesel and T&D are about the same price for standard or W2 rockers.

When all this **** was fairly new the cost of the intake manifolds were close to the same.

The cost factor is an excuse not a reason.

I can only think of one Chevy guy over the years who bit he’d when I told him it was time to upgrade his rockers. Instead of the T&D I wanted he bought some other ****.

Never made it off the dyno. He got to buy twice.

BTW, the cost for a Chevy shaft set up is almost the same as a Chrysler if you are buying the same level of rockers.

The cost excuse is sad and pathetic.
 
NC Engine Builder said:
Behind the scenes we are progressing with the 408 dyno mule, and would really like to find a old milodon superstock oil pan and pickup to borrow for dyno testing. @Earlie A is going to buy the shortblock at the conclusion of our testing, and it will be going into a early A body, and I dont know if there is a suitable oil pan that fits those cars, that will be up to high rpm dyno testing. Definitely like to keep the bearings happy during our flogging!
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Any chance you might go into detail about the modifications done to this short block to keep the bearings happy? In this thread or a seperate thread.
 
92b said:
Any chance you might go into detail about the modifications done to this short block to keep the bearings happy? In this thread or a seperate thread.
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Not really any "tricks" to it. I bushed the lifter bores, which in my experience, is the biggest source of oil leakage in a SBM. Drill the main feeds to 9/32, drill all the pump and filter feeds to 1/2" and use studs and line hone the main tunnel. That's it.
 
rmchrgr said:
I went through that snowball scenario with my 416". The CNC ported iron RHS heads were good but of course I wanted more. Once I had the BPEs it became clear that pistons with a lake of a dish weren't doing me any favors so now it has 11:3:1 flat tops. The old 1 5/8" step headers are good pieces but kind of small so new, bigger headers. The BPE intake ports dwarf the gasket-matched Victor 340 so now has a port-matched Super Victor. Of course the cam is not going to cut it so from 251/259 @ .050" SFT to 263/268 @ .050" solid roller which means roller lifters, roller valve springs and good pushrods plus checking valve springs often... and on and on. It was an exponential hemorrhaging of money. Should have just gone this route to begin with.

View attachment 1716387710
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did you dyno? or any ET's and MPH?
 
NC Engine Builder said:
Not really any "tricks" to it. I bushed the lifter bores, which in my experience, is the biggest source of oil leakage in a SBM. Drill the main feeds to 9/32, drill all the pump and filter feeds to 1/2" and use studs and line hone the main tunnel. That's it.
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Thank you. Will this be pushrod oiled?
 
9secRR said:
did you dyno? or any ET's and MPH?
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Dyno sheet.JPG

This is a dyno pull from my previous 416" RHS head combo. 502.9 lb ft of torque @ 4,800-4,900 rpm and 500.2hp @ 6,000 rpm. This was 9 years ago, April of 2016. You can see it fall off a cliff just after peak hp. Not much in the way of tuning - changed jets up and down and timing once or twice but it didn't respond. Carb was an OOTB Proform 850 so there was likely some power there with a little tinkering.

And clearly, the BSFC numbers on this pull are not great. As I mentioned a few pages back, I discussed this with PRH back then and he had a suspicion the dyno may not have been not properly calibrated The shop didn't use a carb hat for whatever that's worth. The air was good that day (60º, low humidity) and the dyno is at sea level (Long Island, NY). I was thinking it would be around 525-530hp. I told the operator that before we ran it - he laughed and said no way. He was surprised when it hit 500.

For various reasons, I never ran the car with this version of the engine in it. I'm still pretty bummed about that I wish I could have made it happen. I'm my own worst enemy.

In the end, the combination of parts was probably not the greatest and this is what it was. It had a nice, flat torque curve though and would have moved the car out OK (3,000lb Duster). 500 lb. ft of torque from a '340' is nothing to sneeze at.

I think it would have gone in the 10s. I have a freind who has a similar combo (non-ported RHS heads) also in a Duster and he went 10.60s so the potential was there. Before I built the 416" the car had a stock-stroke 340 with mildly ported W2s that went a best of 11.97. Shifted at 7,200 so that was fun. When that 340 last ran it it was going 12.0s @ 110-111 with a broken piston ring in the #5 cylinder. It was also old and worn out, the bearings were from 1994.

Car is lighter now with a better converter so it should run OK with the new combo. A little birdie told me it could go 10.20s when it's sorted out. From 12.0 to low tens is a big jump...

Enough about me though.
 
I'm also going to mention that member @Scampin has his iron-head small block combo on lock. @furrystump is getting closer to the 10s as well in his 'Cuda. Those guys are small block heroes!

Here I am I'm thinking I could go low 10s with max ported aluminum heads, big headers, single plane intake, slicks yada yada but Scampin is going 10.20s @ 130+ in his "stock appearing" Duster without any of that nonsense on Goodyear Polyglas tires. It's just mind boggling how amazing that is.
 
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