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 !!!