I've had this engine built for a while, but life, covid and work got in the way, finally found a couple days to get it ready and make the 5 hour round trip to the engine dyno.
-1978 440 block, bored .030 over, bushed lifter bores, line hone, decks cut square
-Milodon 8 qt truck pan, hv oil pump, windage tray, studded mains and heads.
-Bullet racing cam, mild enough for the power brakes to work in truck application, hydraulic roller, .540 lift. morel lifters
-Trickflow 270 heads
-Indy dual plane match ported to heads.
-Comp cams promagnum rockers, 3/8 Smith Brothers pushrods, B3 racing shim kit.
-Eagle 4.250 crank and rods, Icon pistons 10-ish compression.
_Cometic Mls head gaskets .040, pistons were .009 to .011 below deck
-Proform distributor, QFT 950 vac secondaries with E/Choke.
2" mad dog fenderwell headers.



The torque is pretty good and should be fun in a truck with 37" tires and 5.13 gears. We capped it off at 5200, past there the valvetrain started to lose control and it would break up. If I ever go back into the heads I think I will revisit the springs.
It wasn't real picky, changing timing from 30-36 didn't really change much, neither did a jet change, it was kind of there right out of the box. We did gain a wee bit when we did a back to back spark plug change test.
I'm really glad it runs pretty well, no real leaks, the rear main stayed totally dry with a stock retainer and rubber seal with it installed clocked slightly. We cut the filter open, no metal, some rings particle on the mag plug. I can install the engine now and get the truck so it runs on its own power again, then send it back for paint.

Very nice!

Glad you had a stress free dyno day.

What rpm were you seeing the valvetrain unhappiness start?
The airflow numbers look good all the way til the end on that pull.

I had a lot of anxiety on the drive up there yesterday...
Every time it got in the 5300-5400 rpm range, it appeared, and the dyno operator said it sounded like it was only one or two cylinders at first. When I tested the pressures, I recall that the springs were kind of all over the place and not that consistent. I posted about it once that the Trickflow numbers didn't line up with the PAC specs, from the part numbers provided.
I guess I could shim the springs and retest?

Do you know what the valve springs pressures are open and on the seats?
I'm thinking the hydraulic roller lifters will need more pressure than the standard flat tappet lifters due to the increase weights. I will shoot for 140 to 180 lbs. on the seats and from 340 to 400 lbs. at max lift
I do have a 1400 lb. valve spring tester and a bunch of valve spring shims so i can usually get them within 10 Lbs., +or - 5Lb from each other on the seats and within 25 lbs of each other at max lift depending on the valve springs and actual lift at the valves

I bought a set of 270's with springs and I took them apart and checked the springs, then took them over to Ohio Crankshaft to get a second opinion and I couldn't even remotely make them work. I bought a set of PAC and everything is happy now. Birdtracker

In my notes from the machine shop, I have 140/375 as the spring pressure tested by them. I had done some testing with a hand testers and some were off that number both ways, mostly a little higher in the bottom and little less up top.
Morels spring numbers maybe assume a lighter valvetrain, It's not the lightest with 3/8 pushrods and the iron rockers.

Edit, back to the future
https://board.moparts.org/ubbthreads/ubbthreads.php/topics/2866226/1.html

My .02 would be……..
With 140/375 spring loads, unless that cam had pretty aggressive ramps………53-5400 would be a pretty low point for there to be any type of lofting or valve bounce going on.
That’s not to say it couldn’t have been happening, but at that rpm, I’d consider it an anomaly.
However……….it does show up fairly regularly at a point not much higher than that(57-5800).

That dyno must be at a fairly high elevation……….the correction is quite high.

Also, I’ve had several sets of TF heads here with that 16094 spring, which is a PAC 1294.
TF has different specs for that spring depending on what documentation you’re looking at.

On my spring tester they check the same as the PAC specs, and the TF specs in their valve spring listings.
Those specs are stiffer than the specs that are on the instruction sheet that comes with the heads.

The PAC specs are 154@1.950/431@1.300……428lbs/in

Cam is a little bit bigger than I remembered, but not by much.

Yes, we talked about the elevation and stuff for the tuning, the dyno is at 2800 ft, and the humidity was about 85% . The weather station pressure local to there was saying 26.2 inhg that day. We moved the jet a little because the truck will be mostly in the 3500-4100 ft area for most of it's driving.

I have had motors on the engine dyno start to nose over around 5000 RPM and then start to gain power again above 5300 RPM, more than once
if you test it some more on the engine dyno try taking it 500 RPM above peak HP rpm to see if it is done or not (unless it is starting popping and backfiring through the intake )

I'm under the gun to get the truck together so engine testing is kind of done for now, I can test it some more on the chassis dyno once all the gears are broken in. Although making engine part changes in place on a truck so big kind of sucks..

After seeing how short the duration is on the cam, I’m not surprised by the shape of the TQ curve.

The Hp curve is still climbing slightly, and at least on the sheet you posted, there no obvious signs of a problem.

With Hyd lifters the loss of control point is often like a switch………might be good at 5200, and in the crapper at 5300.

I usually go high enough to know where the end is………then keep it under that point for the remainder of the testing.
You may have done that prior to the pull you posted.

I'll pm you a google link to pull video where it's audible right at the top end.
I guess this is where a spintron service comes into play. There is a local guy that test distributors so I may do that just to rule that out as well.

Thats really good power and torque for such a mild cam.

My only advice is that if you spend about an hour or so relieving/radiusing the branches of the LOWER plenum of that 2D you will probably pick up some power up at the top. The upper plenum as cast flows about 30CFM on average more for each port than the lower plenum, and it doesn't really take that much work to get them to flow much closer to even. Of course It might not make as much difference on a mild torque motor like yours but on my 6800 rpm 517" it was well worth doing.

I had a very similar 508 RB before this one with only ported Stage V iron Heads (flowed on par with Edelbrock RPMs) and that thing was a HOSS

I will keep that in mind if the intake comes off it in the future. The intake was rough CNC'd to max wedge and I did a bunch of hand blending at the port exits and into the runners on it.
When I do the 440 in my other truck, I think I am going to give solid roller lifters a try on that one, will definitely be doing a stroker again. Clearancing the block was a lot of work, but the ft/lbs was worth it.

I haven't built a stroker 440 or 400 motor with a 4.250 or 4.320 stroke crank with BB Chevy rod journals and steel rods that I had to clearance the blocks a lot, maybe a tiny bit but not a lot

Not so on my current build with a KB aluminum wedge block with a 4.500s stroke crank with stock 2.375 Mopar rod journals sizes and steel H beam rods, I had to notch the sleeves at the bottom of the bores on all eight cylinders to clear the rod bolt heads

I could turn everything over before I clearanced it, but I could barely sneak a piece of paper in some places. I had read that .050 is a good number, so I used a tie wrap that was about that thickness and ground out to give it that around the counterweights and casting pads etc.

Way, way better to be safe instead of wishing you had later
Steel rod motor with iron blocks I like and shoot for .030 minimum at 60+F shop temps.
I also use the same clearances on my crankshaft steel scrapers, a little more (.045+) on the aluminum scrapers

I think the intake manifold may be a limiting factor. I have used in a couple of different street engines and managed to make over 600 hp with both (in the end), on pump gas. Had to play with the camshaft a little with the first one to get there, .54" lift, but the other one did it with off the shelf comp street roller, with .59" lift. Still I feel, they would have produced better power with a single plane, and the low end wasn't that great eirher.

If the goal were to simply increase the HP by a fairly significant number……..I’m sure adding 20-25* of duration and .050” or so lift would make big difference.

Of course…….that doesn’t mean it’s the right thing to do for the application.