505 stroker fresh off the dyno - Power seems low? Thoughs?

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Ivoryk3ys78 said:
Those springs may be your problem.

Last year we took my 72 Duster to the track

408
Trickflow 190
11.2 compression
Howard Solid 600/615 254/260@050 108 in at 103.5
Strip Dominator
800cfm DP
727/3500 4.10 / 28

I am pretty sure the springs are the same as you got on the big block heads. They are rated at 120 on the seat and a pac spring isntalled at 1.9.


It only did 113.5 in the 1/4. Something was definitely wrong..

After talking to my friend Mike we took off some springs and tested them. We tested a few at the install height and were only getting like 110 and you could see the scrub pattern on the tops of the valves had been moving around. The valves had been turning.

We started looking to try and find another spring that would work with that same install height and everything and ended up ordering Howards HRS-98632

Valve Spring Set Series:
 Max Effort





Style Of Spring:
 Dual
Outer Overall Diameter:
 1.500
Outer Inside Diameter:
 1.100
Inner Overall Diameter:
 1.100
Inner Inside Diameter:
 .816
Damper:
 No
Closed Pressure:
 145 @ 1.940
Open Pressure:
 422 @ 1.250
Rate:
 413
Max Lift:
 .780
Coil Bind:
 1.100


This ended up being a spring pressure of about 155 Seat Open 390/400 area.

We brought it to the track this year and the car did 118.5. We were not quite wide open we discovered the previous year but it wasn't by much.

I think your issue is those springs. I had wished I had bought the heads with the one size stronger spring.

The howard springs went right in though without anything else needed to be changed. Perfect for the 1.9 install height and everything. Went right in and they are not expensive. They are lik $140.

Howards Cams 98632 Howards Cams Performance Street/Strip Valve Springs | Summit Racing

I am also running there EDM oiling solid lifters. I would imagine when the spring breaks in a little the spring pressure will drop some.
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Well, when I spoke to the main tech guy at Howard's, (can't think of his name) he was shocked I hadn't wiped the cam and lifters out with a spring rates at open pressure of 394. He said it a few times about how impressed he was the cam was still holding on and we were able to break it in without issue. He wants me to check pressure at actual spring hight on installed and full open and let him know.

So I'd be hard pressed to go higher with spring pressure after hearing that. But ACTUAL numbers will of course be more telling then what the sticker on the box says. I've got a nice scrub pattern on the valves thanks to the B3 kit, but I'll keep an eye on it.
 
I think I miss read what you meant. I think your referring to the stronger closed pressure. Anyways, I'll watch the scrub pattern and keep what you said in mind. Thanks.
 
he was shocked I hadn't wiped the cam and liftersout with a spring rates at open pressure of 394.
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Read my previous post where I showed you what your closed and open pressure really is.
It’s not 394lbs........ unless you’re net lift at the valve after lash is about .700 lift.

The spec is [email protected].
Your open height is more like 1.340.
 
Your right, I only had a moment to look at your post when I saw it. Thanks for the info. One thing I'm going to re-verify is the exact lift.
 
I would bet he means he installed it dot to dot and confirmed it was at the right cenerline with the degree wheel and didn't need to put it on a differnt location on the timing chain set.


oldkimmer said:
In post number 7 u say the Howard’s tc&g were installed dot to dot. So which is it? Kim
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Minnesota Muscle said:
To be honest, I'm not sure there is another dyno in the state. originally I asked around on fakebook, and locally and only one business came up, with some speculation of another, but never did get contact info. I will put some feelers out again to see what I can find.

I asked about an air turbine to get air intake numbers, and I was greeted with a blank stare, so I assumed they didn't have one. We did look at a few other builds he had in his records, but nothing was close enough to really compare. He had one that was fairly close but was a roller cam engine, and it was 650hp, but a lot of the engine details were not noted, essentially just displacement and some minor details like carb size.

Yeah, a compression test with a strong cranking would have done me a world of good. I paid out the nose for professional advice and assistance and didn't get it. I won't be going back to Wheeler Dyno and Engine services in Blaine, MN again.
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SDR racing in Sabin Mn has a Mustang Dyno. They also own our local drag strip. Great guys and very intelligent. I just had my Demon on their Dyno last week.

F646E036-C949-4669-9BAE-83A631FFBB4B.jpeg
 
The ignition timing is weird 30* all in? Something is off, verify TDC
Go ahead and verify the cam centerline, correct if needed, as many others have suggested. Install the engine and drive it, the true results will show up at the track in the time slips.
You wont be the fist or last to think their engine build should have made bigger numbers on the dyno.
 
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Demonx2 said:
And????
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Hah! Fair enough, I am 452HP at the tire at 5200 RPM. I gave them a hard stop at 5200 as it is not my race car. Regardless we quit making power right at 52 anyway so it turned out to be a moot point. The surprise was the torque, Mustang Dynos are notoriously stingy with torque. I was north of 400 on torque as well. 413 or 433 don’t remember which. I am waiting for Email with results graphing. I took a pix of screen but it was not very clear. I about peed down my leg while they were winding her up. Long pipe headers with Cherry Bomb glass packs on a Hemi, what’s not to like!
 
Sublime one said:
Hah! Fair enough, I am 452HP at the tire at 5200 RPM. I gave them a hard stop at 5200 as it is not my race car. Regardless we quit making power right at 52 anyway so it turned out to be a moot point. The surprise was the torque, Mustang Dynos are notoriously stingy with torque. I was north of 400 on torque as well. 413 or 433 don’t remember which. I am waiting for Email with results graphing. I took a pix of screen but it was not very clear. I about peed down my leg while they were winding her up. Long pipe headers with Cherry Bomb glass packs on a Hemi, what’s not to like!
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That's great!!
 
Looks like the 27cc dish piston they offer. with a .040 gasket . pistons sit.010 below deck, you should be at about 10:1
 
I've been dealing with some medical issues, but I'm making progress. Engine is finally in and just working on all the plumbing. Once I get it installedI 'll pull the front off and get things verified. Cold weather is coming fast up here, and I need to make sure it's all together first.
 
Minnesota Muscle said:
I've been dealing with some medical issues, but I'm making progress. Engine is finally in and just working on all the plumbing. Once I get it installedI 'll pull the front off and get things verified. Cold weather is coming fast up here, and I need to make sure it's all together first.
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Not sure how far you are from Fargo (Sabin Mn) but the SDR guys run their Dyno most all winter. Keep in mind they are generally about two months out on appts. As you have discovered there are not a lot of Dynos up in our part of the world so they stay super busy. You end up deciding to do a few pulls let me know and you can use my shop as a base camp and I can shuttle you back and forth as they will likely have your car most of the day. Many of the FABO guys have wandered into my shop on occasion, Winters are long the bar is always stocked!
 
Sublime one said:
Not sure how far you are from Fargo (Sabin Mn) but the SDR guys run their Dyno most all winter. Keep in mind they are generally about two months out on appts. As you have discovered there are not a lot of Dynos up in our part of the world so they stay super busy. You end up deciding to do a few pulls let me know and you can use my shop as a base camp and I can shuttle you back and forth as they will likely have your car most of the day. Many of the FABO guys have wandered into my shop on occasion, Winters are long the bar is always stocked!
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That's awfully generous of you! Thank you for the offer. I'll keep it in mind. You get out to Brainerd International Raceway at all? That's about 15 minutes from me.
 
Minnesota Muscle said:
That's awfully generous of you! Thank you for the offer. I'll keep it in mind. You get out to Brainerd International Raceway at all? That's about 15 minutes from me.
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If I was that close to Brainerd I would be divorced and broke! That is just a beautiful facility and a great track. You see a Sublime and Black mostly 70ish Cuda in the pits holler at me. I am done for this year. I tried heading up that way here a couple weeks back but could not pull it off.
 
I hope your feeling better and doing ok.
I have icon 4.382 bore pistons with 16.4 dish that look the same as what’s in your motor, 440 source just advertises as 17cc but it’s an Icon 16.4cc piston. Besides, they use the same photo for all the dish pistons on the 440source site.
That spinning assembly is 10.705. With the block cleaned up, I would think it’s gotta be within.010-.025 deck clearance.
How tall could the block be ? ..What’s the tallest factory block you guys have seen ?
With that cam, calculator says roughly
10.4-10.7 compression and 8.0 - 8.3 dynamic, depending on deck.
The static and dynamic compression ratio calculator

If the deck height is tighter, .00-.010
Static and dynamic go up close to 11-1
and 8.5. Maybe it’s detonating and why power was dropping off over 30* Timing ????
Mix some race fuel in and run it again,
bump up the timing
 
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604B1duster said:
I hope your feeling better and doing ok.
I have icon 4.382 bore pistons with 16.4 dish that look the same as what’s in your motor, 440 source just advertises as 17cc but it’s an Icon 16.4cc piston. Besides, they use the same photo for all the dish pistons on the 440source site.
That spinning assembly is 10.705. With the block cleaned up, I would think it’s gotta be within.010-.025 deck clearance.
How tall could the block be ? ..What’s the tallest factory block you guys have seen ?
With that cam, calculator says roughly
10.4-10.7 compression and 8.0 - 8.3 dynamic, depending on deck.
The static and dynamic compression ratio calculator

If the deck height is tighter, .00-.010
Static and dynamic go up close to 11-1
and 8.5. Maybe it’s detonating and why power was dropping off over 30* Timing ????
Mix some race fuel in and run it again,
bump up the timing
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I appreciate your concern.

The machine shop just cleaned up the deck surface. If it was detonating, I have to think the Dyno guys would have noticed. I'm mostly deaf, but I don't notice anything. We just finally fabricated the exhaust on, so I'll get to drive it on the road tomorrow. It seems to run really well though.

Honestly, I'm more worried about figuring out why it made peak power with the ignition timing is so low. Temps are dropping fast up here in MN. Looks like I'll have it drivable just in time to put it away. I still plan on pulling the timing cover and verifying valve timing before race season. Sure wish I had a ceiling in my shop so I could heat it.

Any other tips on what could cause such low timing would be greatly appreciated. Will give me a place to start looking in the spring.
 
You ever brake rev a car to set timing ?
Brake rev it to 2500-3000 rpm, Turn/advance Distrib until it starts pinging and back it off till it stops. Lock distrib down and check timing. See if it’s at 30*
 
604B1duster said:
You ever brake rev a car to set timing ?
Brake rev it to 2500-3000 rpm, Turn/advance Distrib until it starts pinging and back it off till it stops. Lock distrib down and check timing. See if it’s at 30*
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That seems like a way to find optimum timing for an engine that is octane restricted. Also the timing would be known as optimal only for the rpm and load it was set at. A motor can lose power from too much timing before it goes into detonation. It depends on what the octane requirements are for the particular engine and the octane of the fuel being used. The timing number (lets use 30 degrees) is assuming that the timing marks have been checked to be accurate along with the tdc mark. Also most engines won't maintain 30 degrees through the entire rpm range even if the timing is locked. So 30 degrees happens at a particular rpm. A motor with 30 degrees at 6000 and 24 degrees at 3000 may not run the same as a motor with 30 degrees at 3000 and 24 at 6000. The best way I know is to see what the timing is in 500 rpm increments then sweep the motor for best power under full load then adjust the curve accordingly. That will get you pretty close to optimal full load timing.
 
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Yup, well my best guess is either something is together wrong, balancer is off, keys ways are in the wrong spot, and it really is higher than 30 just not showing it, or it needs better than 91 octane and more timing.
But I’m on my second shift OT with only 5hrs between them and 2 of the 5 was driving back n forth, So I might be wrong,
Maybe
 
Minnesota Muscle said:
The springs are TFS-16893. Installed pressure of 120lbs at 1.875, and open pressure of 394lbs at 1.175. These are the springs that trick flow sends with their flat tappet 240 heads. I spoke to Howard's cams yesterday to pick their brains about things, and he was a little concerned about the spring pressure. He said he generally doesn't like to see more than 360-370.

Anyway, he recommended getting the cranking pressure up in the 185 region, moving in two degree incriments until it gets there. I'll be ordering the stall converter today, then get that in and get the engine dropped in quick. At that point I'll pull the timing cover and check/adjust the cam timing so I can crank it over.

I plan on 30% street and 70% bracket with the car. Just taking the kids to school, a few local car shows and such.
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Just be aware that advancing the cam makes you loose intake valve to piston clearance. So recheck this first with checking springs before spinning the engine over by hand or with the starter and bending your valves.
 
Where did you have it dynoed? My old boss and myself have always had good results from R&R Performance in spring lake park.
Over 10 yrs ago we took a 512, edelbrock heads, I believe 238 @ 50 hydraulic roller cam, performer rpm, 750 demon carb. It made 538 hp and 624 ft lbs. Granny could drive to get groceries. That was a very nice running street motor.
 
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