First Dyno Complete
 

Hey guys, I did not end up going to Smitty for my dyno work. I just couldn't see making the 2+ hour one way drive. I was however, able to get in at Performance Engineering in Jenison. They have a nice dyno set up and they were very easy to work with. Hoping to run the 2nd engine tomorrow. They have a little more work to do on the carb because there's a slight hesitation off idle but other than that it ran great. Looking at the printout, I plan on propping so WOT is now 5300 rpm. I can set the rev limiter with the distributor. Would you also set that for 5300? Thanks for your advice. https://cimg5.ibsrv.net/gimg/www.off...830289fbcb.jpg

My opinions/thoughts ….
Some rev limiters can stop dropping cyl’s just before rev limit set point. Also, i use rev limit to only limit rpm when engine is ‘winged’ by mistake (getting air/ cavitation/ missibg the throttle, something breaks / etc….so i like say before valvetrain will have issues. Anywsy, without knowing your set up, i’d go for 6k rev limit.

Speaking of valvetrain - looks like you may he running into lifter fuss or valve train fuss (starting to lose control) - see how hp lowers than rises and does it again. Just going by sheets - don’t know your specifics

I'd set the rev limit to around 5600-5700rpms.

He did say that he stopped at that rpm because he noticed that there might be some distress and it stopped making power. I have the AFR 265cc heads with the 112cc chamber. I did not upgrade the springs but I believe they are supposed to be able to handle a decent cam "as is". My cam is a roller 230 236 @.050 and the lift is .547. Full roller rockers too. I think somehow I ended up with a taller(?) roller lifters. The guy who built it for me said they were taller than what he usually uses. Could be the added weight of those is causing that if that is correct?

The up and down power up top is likely valve control related. What spring is it?

Before you talk about rev limiter you wanna fix that vave train before you run that thing .

What are the chances that the problem is a plug wire? I only ask because the #3 wire pulled on and off without any resistance and he suggested that I get new wires. I have ordered new wires regardless for both engines. If the twin runs without any distress I'm going to assume that was the problem. Any thoughts on this?

I try to educate myself on something every day if I can so...for those who have experience in these dyno pulls...what exactly is it that gives you concern about the valve train in the data from these pulls?
Thanks

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.

I'm pretty sure the 503 hp number is because of dyno inertia and not the valve train if this particular area is the concern

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 # ?

You threw on those heads out of the box? No changes for marine use? (larger clearances?)

Dramatic fluctuation in power above 5000 and those variances increasing more and more as it approaches 5700. Most of the time this is valvetrain related.

PAC has many different grades of springs but I'd think that is enough for this RPM range. You'll know more if the other engine does the same thing. Keep an eye on the servo valve on the dyno when it gets up there 4800-5700 on today's pulls and see if its fluctuating a lot. They can give you a printout of that servo control also. If the water brake setup is not dialed in for this power range it can have trouble controlling the engine. I change quite a bit going from a 300hp engine to a 1000hp engine to a 1500hp engine...it's a lot of setup.

No AFR readings?

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.

I don't think anyone was meaning to put you into a state of concern, just some guys that look at a lot of dynos and have been around them awhile. I live on the dyno and have never really heard valve float. If its that bad its past that...if I'm in the room with the engine all I hear are my 3 brain cells hitting the metal plates in my head and if I'm sitting out at the dyno stand door closed I am drinking a beer so all noises heard are ignored LOL! Could have been water brake control or other things as well.

Did the second engine look similar? Would be cool to see the graphs laid over.

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.

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.
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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!

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.

:D

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Attachment 577539LOL!!!! Now I get it!!! Valve train distress. What do you think with the given info? Just springs?

Unless something has changed at afr, their valve guide clearance has always been too tight for marine use. I had a set cost me a lot of time but luckily not too much $$$ even though the “salesman” ensured me many many times they were fine and to the “marine spec”

So this is the 2nd time I've heard that the valve guide tolerances were too close for marine use. Is that across the board with AFR or just my heads?
Is there anyone else running these AFR heads?
Just because I'm enjoying my ride down De-Nile, doesn't mean I'm not listening.
Thanks for your help.

Across the board. Just hate for you to stick a valve and wipe out the whole motor

Completely agree. Out of the box any head is not set up for marine use and you have a good chance of sticking a valve.
In a car the head expads at a similiar rate as the valve because coolant is near 180* or so.
I don`t know where you boat but I`m pretty sure the water isn`t 150* and your water temp isn`t anywhere near 180* ... so the valve will expand but the head won`t.. you may be just fine but I woudln`t take that chance.
None of this has anything to do with your bouncing HP numbers , theres something else going on there , doubt theres valve float at 4700 but something is going on there .
I have a great head guy in Illinois if you need one.

I can’t speak to your heads, but back in 09 or so I bought a set of 290 AFR heads for a street car. Dropped them off at the shop only to come back a couple weeks later to realize they were completely disassembled. It wasn’t a dig at AFR, but my guy said he pulls all “assembled” heads apart before installing. I don’t recall any major issues, we ended up swapping retainers because they were a bit small for his liking (creating wear/play) and the springs were shimmed kind of strange which was also corrected.

Again, not saying there is an issue but from my limited experience buying new assembled heads, they weren’t perfect out of the box as one would expect.

I also understand your position of having two motors ready to go in that may be spot on and run fine for hundreds of hours. Flip side you pay to install/remove/repair/install.

540Fever, Yup. I missed almost 2 full season's working on these engines between cash flow and everything backordered. Now finally done and It seems everyone thinks I have 2 expensive grenades ready to go off at any time. Obviously it would be beyond terrible if they do grenade but I can't chase something based on opinions of people that had no hand in them at all. Ultimately I'm going with the guys that built and dyno'd these engines. Neither see's a problem with the printout's or the way they performed. If you boat on the Grand River or Lake Michigan and see me getting towed in, be sure to wave and tell me you told me so.
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What would it cost, and take for time to pull 1 head and bring it to the shop and have the valves removed and clearance checked?

I was trying to buy a boat for sale on here a couple years ago, guy had owned it for a long time, had just finished building 2 555’s for it. He sent me the build sheet/parts list and I offered to buy the boat without the engines for one price or for a bit more with the engines but I didn’t want to even start them.
Seller said he needed to get a bit more for the boat and took another offer of a few bucks more.
The buyer was very green to performance boats, had the boat shipped, stored for the winter, serviced in the spring and as they prepped it for him to use in the Tres Martin course, the first time they ran it under load, it dropped a valve and DESTROYED the engine.

This is only funny for you guys. Believe me, I'm not laughing even a little bit.
I just visited the AFR website and looked at the info for my heads (I'm calling it small print) and low and behold you OSO guys are f'n CORRECT!!!

• Valve Guide Clearance - Your AFR Heads come with proper guide clearance (.0012"-.0016") for most applications. Boosted/Nitrous or marine applications might require additional clearance and it is the customer's responsibility to verify proper clearance in these applications.

So while you guys are on a roll what should be the clearance for marine use for these heads?

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Ouch...

Well at least they are still out, not that big of a deal at this time to pop the heads of and get the clearance correct. I would call your self lucky. While at it your guy can make sure all spring install heights are correct.

BTW

There used to be a guy on here that dropped a set of "ready out of the box" heads and they seized a valve, forget his screen name Had a old Cig Mystic and then a 38 gun, from Northern Ohio. Full force?

“But the guys on the internet said” :)
I know, tough to say to someone face to face or on the phone huh.

Thanks to everyone who kept after me about this. I wouldn't have given it a second thought if not for you guys and yes, I'm sure that they would have been a couple grenades the first time out.
I will remove them and get things figured out with the machine shop. Still looking for the clearance required for marine use so if anyone knows I would appreciate it. I do have an email into AFR but I have emailed them in the past with no response. AFR says they are now .0012 - .0016
I could have kept my findings to myself but you guys really deserve to know that you were right (of course you knew that already) and I am grateful for your help.
So, can I reuse ARP fasteners or are they a one time use? Kicking myself now because my builder suggested going with head studs and I said, no need, these are never coming off again. https://external-content.duckduckgo....d1b&ipo=images
I hope looking into this will reveal what is wrong with the valve train. These were going into a boat but they would have worked nicely in a car or truck too which AFR says the clearances are good for.
I'll let you guys know what the machine shop finds.
I'll have them check the "spring install heights". Interested in anything else I should ask about.
Thanks again for all your help

Arp bbc head bolts are reusable.

please double check your spring psi’s as installed and open heights. Address this if an issue.

Installed height for both are: 1.920 and 155lbs
Open ht is 1.370 and 340 lbs
bind is 1.187 and 550lbs.
I have no idea what this means. It's on the build sheet.

I believe this bit Full Force awhile back as well.

Bit me as well on a new set of Brodix heads. We set mine at .002, no more problems. It is a pretty tricky measurement though, if you have 10 people measure it, you will get 12 different numbers.

make sure you use the ARP assembly lube when reassembling the engine and proper torque sequence on the heads