The 541 is headed to the dyno! Results are in!

I finally got the 541 all buttoned up and ready to dyno. Moparts member sr440 is kind enough to let me make a mess on his dyno tomorrow.


So, what does the brain trust think? I'm pretty sure I got the cam and all the pistons in there so it just might run.

4.50 crank
4.375 bore
10.5 compression
Edelbrock performer heads with a full CNC job
Hydraulic roller 235/241 cam with 589/571 lift 112 LSA
Comp roller rockers
Old Weiand tunnel ram converted to front facing port injected intake
1700 cfm throttle body
2" dyno headers will be replaced with my 1-7/8" headers when it goes in the car.Don't want to smoke the ceramic on the dyno.


The idea behind this thing was to have an oversized cruiser with stupid amounts of torque with HP being whatever it wants to do.

What's your guess on power?

i'm gonna guess about 550lb-ft at 2500-3000rpm and a peak at about 4200rpm, maybe the peak will be about 620lb-ft
hp around 550hp, maybe 5300rpm?

this one will be interesting. not your typical build..

550 +/- @ 5300, 650 ft/lbs @ 3800. Flywheel horsepower.

If it's anything like my 493 it will fall off a cliff shortly after peak power but my RPMs are pretty much OOTB with the exception of a good valve job.

Kevin

My take on it is.......
The Weiand TR is too small to support 541” at any kind of higher rpm, so I’m expecting to see a pretty big TQ number, then the HP will peak pretty early.
As a result of the early peak the HP number won’t be all that big.
I’m thinking the TQ/HP numbers will end up pretty lopsided, towards the TQ end of things.

To throw some numbers out there(which will be a total “WAG”), 660-670ft/lb, 550-560hp.

In order to know how the basic long block combo compares to “the rest of the world”, it would need to be tested with a “known quantity” induction on it.

I'm going to say vey close to 700 ish TQ very early & 520 to 540 hp

i'm not going to guess any numbers because i'm not smart enough to come up with any.
however, i will say i think the torque will move that imperial out in a way bigger step than you might think.
i'm waiting for driving impressions after the engine is installed.

The intent of the build was to make silly amounts of torque over a usable range. HP was never a concern. It was going to fall into the Rolls Royce range of "sufficient".

This thing needs to pull down the highway at 1700 rpm and still have a full normal rpm range.

It's an unusual build for sure.

Mechanically, the upper limit of the usable rpm range will likely be determined by the valvetrain.........although the hp peak should occur well before that.

If it peaks between 5200 and 5500 I'll call it a proper job.

The Imperial needs a high torque low rpm engine but I didn't want a tractor motor.

You should have your answer in about 24hrs

mine made 725, buddy son made 705. less stuff than ours. i will guess 645 hp and 605 tq.

Cam is small so that will restrict the power but you should have great torque. I'm going with 650 torque and 525 hp as a guess. Hopefully it starts, runs good and doesn't leak. If it does those three then it is a successful dyno day. Fine tuning can always take place down the road. Are you confident of the EFI tune at this point or will you need to dial in that tune on the dyno?

No guesses, but Good luck with it, hope it runs well for you.

It's your cam so it's all your fault anyway.


When I've discussed the build with other engine builders they like the combo.

People have to understand that it's not a horsepower build. This thing needs to have a strong vacuum signal, be happy lugging a 5300 lb car down the highway at 1800 rpm, idle fairly smooth, and make absurd torque everywhere in the rev range.

I'm pretty sure it'll do all that.

I'd be happy with that torque and maybe a wee bit more hp. Maybe 540?

Rich Nedbal from FastmanEFI.com will be remoting in to build the tune.

Hopefully all goes well and you're happy with the results!

There is probably some power in opening up the ports in that tunnelram. The question is, how will it affect the torque you prize. I like your build.
At first I thought it might be limited to low 500 hp teritory. But it might surprise us. I will guess 560 hp. max torque 660 at 3400? No matter what, you are going to love the way this deal runs!

660 lbft, 575 hp

Going to make at least 1hp/ci, I'd guess just over 600hp, and high 600's for torque. S/F....Ken M

Ringer alert

I'm. Guessing 650 hp and 600+ tq

618 horsepower, 645 torque

Why you have to do that to me?!?!?! Can you PLEASE be wrong for a change? Just once?

Phrase of the day: valve float

The activities were cut short by the onset of valve float.

Today was a rather miserable day for this kind of thing but getting three busy schedules to line up is kinda tough. Outside temp was 104. Inside temp was 104. That beats the forecast of 107.

Anyway, after plenty of fussing and head scratching, we got everything lined up and talking to one another. It wasn't the worst day any of us have had playing with engines but it took a while to get everything straightened out. We struggled to get the throttle blades set properly due to Accufab's use of hardware that was neither inch standard or metric. Eventually, we found a fix and moved ahead,
That problem sorted, we lacked a steady throttle position due to a serious mismatch between my weirdo one-off intake manifold and Joe's dyno. Initially we had full throttle but by the time we made a pull WOT became 55% with 4 inches of vacuum. Improvise! Adapt! Overcome!
After getting it straightened out the engine behaved itself for the most part and we got a little tuning time in.

We didn't baby this thing. I told Joe it was going to have a 180 degree thermostat so that's where we ran it. None of that 130 degree pretty number stuff.

A whopping 5 full runs were made over the course of the 8 hour day. Believe it or not, other than a little minor clean up the initial run was the best we had. My little Comp double valve springs lost control around 5200 rpm but there's not likely much more to be had.

You guys like data so here's your data. Andy, you were pretty stinkin close.

I gotta say, the torque does not disappoint. It did exactly what I wanted it to do. Sure, it would be nice to have a 10-15 more hp but if I get the valves under control I think it'll be an awesome cruiser.

This thing idled smoothly at 850 and was pulling 14 inches of vacuum. Look at those BFSC numbers! Is it possible to build an eco friendly 541?

I need to decide if I want to shim those valve springs or just slide in a bit beefier units.

In all, I gotta give a tip of the hat to Dwayne. I told him what I wanted out of my one-off weirdo engine build and he delivered. It would be pretty hard to hit any closer on such an unusual build.

Now I gotta stuff it in the Imp and see what breaks first. Maybe we should take bets on that. Axle? Driveshaft? Transmission? Unibody?

Oh, the last nerdy data chart...

I would shim the spring up closer to coil bind even if you go to a stiffer spring, your already in there so?

That will be a fun car, I don't see you breaking anything unless you put a good tire on it. And speaking of tires, your going to need a lot of those lol.

A Banks kit for a motorhome 460 ford had 50 inch primarys in the 4 tube headers. It was amazing how much better that rig pulled. The claimed torque increase was 87 ft lbs, as i recall. And it had every extra one. It would be great to see just what that would do for your 541.

Glad you got it up and running....... with no major hurdles to overcome.

So, here’s the thing with hyd lifters and spring loads........
“Valve float” and lifter bleed down act pretty much the same on the dyno.
A little extra spring load will usually show some degree of improvement if it’s regular old valve float.
If it’s lifter bleed down, it won’t really show any gain with more spring.

What are the springs, spring loads, and lifters you used, and the preload setting?
Was the valvetrain fairly quiet?

You can see the bsfc numbers are decent until 51-5200, then the valvetrain gives up.

Im sure there would have been a few ponies left on the table if it could have made it to say, 5600 or so.

Anecdotal hyd roller lifter story.......

We had a 446 on the dyno a couple years ago. HR cam from the same lobe family as Feet’s cam(this family of lobes is supposed to be fairly rpm friendly).
1.5RR, prepped(no porting) RPM heads with Isky dual springs set up at about 145 on the seat.

After several pulls were made, increasing the rpm every few pulls to get a handle on where the valvetrain was getting unhappy.
It seemed to be pretty solid to 5800. Then it was turned up to 6000.
It was peaking well below 5800, but we wanted to know when it got unhappy.
On the second pull to 6k, when the pull was over there was some unhappy noises coming from the engine.
Pulling the valve covers revealed two rockers with a bunch of slop in them.

In this situation it was easy to determine if it was valve float, or lifter bleed down.
Since two of the lifters had collapsed and the pushrod seats were stuck all the way down...... it was lifter bleed down.

That’s how quick it can go bad.
No indications of a problem at 5800....... stuck plungers at 6000.

The lifters were Howard’s “street series” 91767, which are made by Morel.

I will add this.........theres lots of good data on those sheets.

Very complete....... not just a page with the basics

You guys are probably somewhat conditioned for it being that you’re from down there.......but 104*+ in the dyno cell doesn’t sound all that pleasant to me.

You're going to have fun with that. Congrats man. Sounds like alot of work.

First thing to give up? I'd have to vote motor mounts, followed by U joints.

My guess of 525 hp and 650 torque was fairly close. 104 in the dyno room sounds like hell to me. We typically dyno in the morning during the summer and the outside air will be in the 60's. We've run a few times in the afternoon with the temp up in the 80's or 90's and it gets miserable really quick. I'm actually impressed that you guys got the testing done in one day with a new EFI build in that heat. We often spend one whole day getting a new EFI engine on the dyno and then spend a day testing. Weird EFI engines sometimes take 3 days on the dyno since so much stuff has to be sorted out. At least it wasn't dry sump? A dry sump engine adds another few hours to the install time!

One more thought........
Could you guys “hear” the valvetrain getting unhappy?

The reason I ask is........ when you get outside the upper limit of the wave tuning window on a TR manifold, the power curve will tank in such a way that it very closely resembles a valvetrain issue.

I tested a 451 low deck motor with a dominator and a TG4500 manifold and was making pulls to 7300, with no signs of valvetrain control problems, or a big drop off of power(peaked around 6800).
I swapped to a Weiand TR with 2x650 carbs and the power peaked way earlier, and at 7300 the power had fallen like 100hp and there was a halo of fuel mist floating above the carbs at the top of the pull.
Had I not already just been running the motor to 7300 with no problems using the single carb, I would have been trying to chase down a valvetrain issue....... an issue that didn’t exist.
I later did some research and measuring and came up with data showing that “by the math”, that TR on the 451 would have been tuned for 5900 rpm.

With 90 more cubes, that number would be noticeably lower.

I bring this up since 51/5200 seems like a pretty low rpm to be have a control issue....... unless the springs are really just not up to the task.

Just to illustrate how the weather affects the power.........
Looking at the fuel flow and bsfc...... and looking at just one line......4900rpm(peak HP):
223.8lbs/hr with a bsfc number of .494, works out to 453 uncorrected HP.

That 4700ft DA is a power killer.

Welcome to Texas HEAT LOL , I was close on HP, but WAY off on TQ , that manifold runner length must be shorter than I thought. The 3 ram pulse timing must be wrong for the combo in my opinion, but still will be a handful in that big ole Car

It’s always fun to “what if” someone else’s stuff

It would be interesting to see what would happen with something like a Victor or TF intake on it and a big 4150 carb.
Both from an absolute power standpoint, as well as the shape of the curve.

Mostly it would be to quantify the effectiveness of the current induction system.

Yes it is , its nice to see all the dyno info also.

I like how the channel order on the one sheet is set up to show both the std corrected data, along side the std corrected with inertia.

At 9am here it is 100..Wont see 60 until later October here

Sounds like you got exactly what you wanted. What hydraulic roller lifter are you using?

I got there at 8:15 and we didn't waste time putting it together. We were on the horn with Rich by 10:30.
The heat was climbing and surely added to the frustration. To make matters worse, Rich was sick and feeling pretty bad. I'm sure he was ready to give up on us a few times.
By 3:30 or so we got a full run in. Heat was miserable. The USB extension wasn't working so we had to leave the laptop in the cell. We got some good quality sauna time standing next to that beast at idle. To make things more fun, we were using Joe's fenderwell headers.
I got out of there (and out of Joe's hair) just after 5 pm.


I'm running Gatorman lifters and Comp 1.5 rollers. The valve train was very quiet. Quieter than I expected. When it ran into valve float the engine started dancing around.

As for the springs, I'll have to look for the part number. I had them shipped to the porter and he did the assembly.

Dewayne, I posted all the nerdy data for you to peruse and maybe a couple others would appreciate seeing it.

Thanks for sharing the Data !!!

That would be a new one for me.

I’d expect the Gatorman lifters to hang on well beyond 5200 with those cam lobes and 1.5 rockers........ provided the springs and pushrods are stiff enough.
If the springs seem to be correct, and set up properly, then it nosing over at 5200 might just remain a bit of a mystery for the time being.

I used these springs: https://www.compcams.com/dual-valve-springs-1-509-o-d-outer-697-i-d-inner-3.html


Max Lift: 0.665
Installed Height: 1.9
Coil Bind Height: 1.175
O.D. of Outer: 1.509
I.D. of Inner: 0.697
I.D. of Outer: 1.125
Spring Style: Dual
Spring Rate: 395
Seat Pressure: 111
Damper: Yes

Well, dance around may be a bit strong. When it got up close to valve float the engine began to wiggle around.

I was eyeing the Holley datalog. Intake air temp was hovering around 130 degrees.
Yeah, the cell was a bit warm.

It looks like I edged out the mighty AndyF with my power guess over on the discussion page.

That is not a hydrualic roller spring in my opinion. Should be 140-150 on the seat and at least 400 open. From what I can tell your around 110 on the seat and 335 open.

I suspected you may have had Comp 925’s on the heads.

I’d change them if it were me.

Way easier to do it now before the motor goes in the car.

Agreed

What's your recommendation for better springs?

Watch it now, he is a site sponsor, better keep quiet and stay out of trouble .

I’d have used the Isky 8005A, installed at 1.840-1.850.

Set the springs you have to 1.8 and you get 150-415 or thereabouts.

The 496 in my Coronet made 613 hp and 631 torque so one could argue that I only gave up a tiny bit of torque to pick up a bunch of power. But, I have a feeling that the cam used in my 496 would not be happy pulling a heavy Imperial down the freeway at 1800 rpm. It would probably pull the car down the racetrack a little faster, but cruising in OD is a really tough trick for a performance engine.

I'm not convinced that the induction system on that engine is great for that application but it would take a bunch of testing to find a better one that fit under the hood so I think it is what it is.

I knew my build was going to throw away a lot of easy power but it makes no sense to build an engine that won't do what the car needs. Looking at the datalog the engine was idling around 48 kpa. That'll keep the power brakes happy. There should be no such thing as a soft bottom end on this motor and I imagine it'll be happy dragging the Imperial around.

As for the intake, I had it so it went on. I expected it to fatten the middle of the curve but I didn't think it would quit that hard and fast.

I explored the idea of TF 270s but I couldn't find a decent intake that would fit under the low hood and work with the MW ports.

Yeah I agree with your decisions. They aren't perfect but they are the best you can do with the resources that you have. It would require a major R&D effort to optimize an intake manifold that engine in that engine bay. And the camshaft choice just has to be what it is or else that engine won't work right in that car. My engine idles at 58 kpa which is significantly rougher than 48 kpa. My engine would have significantly worse gas mileage on the freeway than your engine just due to the slightly larger duration at 0.050 and the little bit of extra overlap.

If I could pick your mind a bit more...

When the power fell off the engine began to wiggle around a bit. I didn't notice any jumps in the rpm. In the first pull we hit the suspected valve float and the engine dances around a bit. The second pull shut off a bit earlier to go easy on it and there was hardly any wobble. Pull number three went a little higher again and it was back to bobbling about.

Can valve float and/or the intake giving up cause it to waggle only in that part of the pull? It is rather amusing to see the camera get all twitterpated with the harmonics in the room.

I suspect engine balance rather than valve float or intake ram effect. Could be the engine or the dyno driveshaft but looks to me like the engine gets into a harmonic wobble at a certain RPM.

Not really surprising to me, it's like throwing the brakes on the entire setup.

I would say after posting your spring pressures that valvetrain instability is confirmed rather than suspected. (so fixing that should make a huge difference)

I’m not sure how you’re coming up with that.

Valve lift = .590
Spring rate is 395lbs/in
395 x .590 = 233
233 + 150 = 383

For something that’s going to see a lot of miles, I’d prefer to not have the springs set so close to coil bind.
The 925 is 151lbs @1.800, and coil binds at 1.175”....... so .625” available travel -.590” valve lift is .035” from coil bind.

If one really felt like they needed over 400lbs open load(which only exacerbates the lifter collapse/bleed down scenario) in this application, you’d want to use a spring with a higher rate....... like a Comp 929(439lbs/in).

439 x .590 = 259
259 + 150 = 409



Actually, I didn’t see where it was posted what the spring loads are....... just what the springs themselves are.
Depending on exactly how the springs are set up, the loads may or may not be way too light for the application.

On the 1st and 3rd dyno pulls, I can hear the engine start to get a little ratty at the top of those pulls.

You can also look at the dyno sheet and see that the acceleration rate isn’t real steady at the top, and the computer is making big changes to the load trying to chase/maintain a smooth/constant rate.

Andy, how high did you make pulls on the 496?
That cam used lobes from the same families as feets cam.

We pulled to 6200 or 6300 rpm. I don't have all of the dyno sheets here in my office but I don't recall any valve train issues. But I used the conical valve springs from Comp. That engine probably didn't need the conical springs but I thought they were cool and I had used them on a previous build so I went with them.

All the conical springs from Comp(if that’s where you got them) have a pretty high rate.

My notes say that I used Comp 7228-16 but I honestly don't remember. This wasn't a magazine build so I didn't keep really good records. The picture I posted seems to confirm that they are indeed conical springs so I'm going to assume that my notes are correct on the part number.

Two questions, is there a beehive spring that fits your cam? And what can be done with the tunnelram? Many years ago i had a 535 with 906 heads, picked up .15 et in the 1/4 by hogging out that tunnel ram on it. Those two together might make a big difference. If you have a converter built to 340/hemi specs, it will flash over 3,000 rpm , (3400?) a nd that allows a little leeway in manifold tuning, i would think.

Congrats getting it going!

There was a BBM on the dyno here last week.
Not a build we contributed to...... just provided the dyno service.

TF heads with their HR springs(PAC 1294), TF HR cam, Howard’s HR lifters(not sure which version), HS 1.5 rockers.

Tthe report I got is things were solid thru 5800rpm, and at 5900 the lifters gave up.

Those heads come set up with the spring installed height at a nominal 1.950”.
The specs for the PAC 1294 are 154@1.950/410@1.350.

5900 is a little low, I bet the owner was unhappy with that. The TF cam really needs to be pushed past 6000 rpm with a 440 to make peak power.