First Dyno Complete
#11
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Not really that #. The #’s before…starting at about 5200. Also remember, most engines produce peak hp 1200-1400rpm over peak torque…few exceptions of course (tuned long runner efi intake as one example)
What springs ? What height installed ?
What lifter ? What cam # ?
What springs ? What height installed ?
What lifter ? What cam # ?
#12
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You threw on those heads out of the box? No changes for marine use? (larger clearances?)
#13
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I went to the AFR site and this is the spring package that comes with the heads.
PAC Racing Springs 1.550” OD Solid Roller Dual Valve Drag Race Spring, 220 lbs. on seat, .710” maximum lift, - 260* max recommended duration, Max RPM 7200-7400
PAC Racing #1940 1.550” OD Hydraulic Roller Dual Valve Spring, 175 lbs. on seat, .725” maximum lift, Max RPM 6500-6700
The only change I made when I ordered was for Inconel exhaust valves and hard anodizing which AFR recommended for marine use.
PAC Racing Springs 1.550” OD Solid Roller Dual Valve Drag Race Spring, 220 lbs. on seat, .710” maximum lift, - 260* max recommended duration, Max RPM 7200-7400
PAC Racing #1940 1.550” OD Hydraulic Roller Dual Valve Spring, 175 lbs. on seat, .725” maximum lift, Max RPM 6500-6700
The only change I made when I ordered was for Inconel exhaust valves and hard anodizing which AFR recommended for marine use.
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Formula 353
Merc Racing 540s
Formula 353
Merc Racing 540s
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#14
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No AFR readings?
#15
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Thread Starter
Just got back from running the second engine and there is absolutely nothing wrong with either engine. They are both smooth from start to finish with no signs or sounds of valvetrain distress or any distress at all. He said he has run engines that do have "valve float" and you can easily hear it when it happens. Could be an anomaly with the dyno unit itself but nothing with the engines. I do appreciate your concerns but all is well. Really looking forward to this upcoming season. AFR was no higher than low 13's and it should go a little fatter with my wet exhaust.
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articfriends (12-30-2022)
#16
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Just got back from running the second engine and there is absolutely nothing wrong with either engine. They are both smooth from start to finish with no signs or sounds of valvetrain distress or any distress at all. He said he has run engines that do have "valve float" and you can easily hear it when it happens. Could be an anomaly with the dyno unit itself but nothing with the engines. I do appreciate your concerns but all is well. Really looking forward to this upcoming season. AFR was no higher than low 13's and it should go a little fatter with my wet exhaust.
Did the second engine look similar? Would be cool to see the graphs laid over.
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Formula 353
Merc Racing 540s
Formula 353
Merc Racing 540s
Last edited by DRAG; 12-30-2022 at 11:53 AM.
#17
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Thread Starter
DRAG, Thanks for your input. I was in a state of "relief" after running the 2nd engine. Didn't intend on sounding defiant or whatever. Just relieved to hear the 2nd one run and to go over with the dyno guy the questions I had and some from this post. Yes, this engine is very close to the first one. I neglected to grab the sheet but will be picking them up next week with all of the paperwork and I did ask for an "Overlay" of both so I could see the differences. I'll be sure to post them.
For ICDEDPPL, yes. They were installed right out of the box. AFR recommended that for marine use, that I should order them with Inconel exhaust valves and to have the heads hard anodized. Which I did. I feel as though if there was something else they would have mentioned it.
I also misspoke about my dyno guy, he only ran to the 5600 because they stopped making power so what would be the point and again, he never thought that either engine was having a problem.
He has a wide band 02 sensor in each side to watch but nothing prints out. He said he goes by the BSFC numbers? DRAG, do you use BSFC too or a combination? Anyway, I was watching those AFR gages during the runs and they were in the high 12's and low 13's. Should fatten up a little with the wet exhaust. Hoping it's not so fat that I get soot on the transom.
And again, I am really looking forward to this upcoming season.
For ICDEDPPL, yes. They were installed right out of the box. AFR recommended that for marine use, that I should order them with Inconel exhaust valves and to have the heads hard anodized. Which I did. I feel as though if there was something else they would have mentioned it.
I also misspoke about my dyno guy, he only ran to the 5600 because they stopped making power so what would be the point and again, he never thought that either engine was having a problem.
He has a wide band 02 sensor in each side to watch but nothing prints out. He said he goes by the BSFC numbers? DRAG, do you use BSFC too or a combination? Anyway, I was watching those AFR gages during the runs and they were in the high 12's and low 13's. Should fatten up a little with the wet exhaust. Hoping it's not so fat that I get soot on the transom.
And again, I am really looking forward to this upcoming season.
#18
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Thread Starter
Got the engines back and the paperwork. He was not able to "overlay" the 2 engine graphs. They are pretty close to each other or at least as close as you would expect? I do like the look of the curves he printed out however you can see the actual data points so maybe just a decent curve? My understanding is the higher hp numbers at the end of the run are not actual. Something to do with the dyno. Inertia? Anyway, very happy with the combined 1002.3 hp.
#19
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I wish I would have saw this sooner like before you went there...I'm not going to get into bashing anyone on the internet but I will say I would be VERY cautious of any advise that place gives you....especially regarding dyno numbers or valvetrain advice....looks like you got a couple solid 500 hp runners! glad it's all working out!
#20
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Thread Starter
BBYSTWY, Thanks for taking a look. The dyno guy just verified that the tune and carb were good and then did the pulls. He didn't assemble anything. When I was there during the session, we didn't hear anything that gave us pause. The other shop who put them together for me didn't spec anything out, just did the block work and assembled what I brought them. I am going to prop as close to 5300 rpm as I can. I am interested in your opinion on what you see especially if it is something I can correct before they get installed and or I go for my first run and set off a grenade. If it's the appearance of the valvetrain distress in the upper numbers, I'm not convinced there is a problem at least nothing we heard. Someone else commented that it could be the way the dyno is set up? Anyway, feel free to let me know your actual thoughts.