Testing RPM Limit : UPDATE Results

Since the tracks are closed and the weather is summer like still here,I started looking for a/the reason my 440 does`nt like to make power over 5,000 rpm.

Been all thru the fuel demands/AFR stuff,no improvements.
3 different cams.
Checked valve springs,only a couple tho... shop said OK? 112 seat.
Checked exhaust back pressure .5lbs,nothing there.
Different octane fuels nope.
Hood off,nope.

So I`ve been told that the blower cant feed it and thats why it noses over like that.
So I took the blower off and installed a 4bbl. intake. Weiand Team G.
I had it in the attic from a package deal some years back. Man that thing is HUGE in the plenum,sits as high as the blower.
NO,,,, it NOT ideal for my engine but I ain`t buying something just to test.

1st trip. run surprisingly good till about 5,100 just gives up and pops once.
2nd trip 1st gear only DOWNHILL ,held it to the floor. Got to about 5,200 popped once and made it to 5,600.
Should have redlined and blown up.

So evidently the "tested" valve springs are not up to the job.
What are people using on a .509 hyd. cam these days?

Pretty sure I have Comp 911 springs in my old 440 w/ the 509 cam. That thing'll scream to 6300+ rpm easily.

Been a while but if I recall- used to set them up at 125 seat/ 300-350 open at .500".
My 6bbl stocker used the same rate back in the day and would run to 6500 without a hiccup.

are you using the mopar lifters ??? never had luck with those - but spring pressure seems to be a little low at the seat - do you know what the open pressure was?

Have Crower "cam saver" lifters in it now. 1 turn of pre-load .020 I think?
Did use mopar lifters on it the 1st time.
Don` t remember open pressures

to me it seems you are just running out of spring and going into float - hence the pop you are hearing - might be worth checking the open height pressure and installed height

I am going to get fresh springs,probably Comp 911`s.

I am going to test the old ones and see whats up.

Good news is that 11.09 with a 5,000 governor looks pretty good now.
i will have to slow the blower down and start over.
3 cams
2 converters
2 carbs.
2 exhaust systems.................LOL

112 on the springs sounds a bit low for a hyd
cam.. I ran some MP springs on one of my roller
cams.. the springs were way off for it.. it
would top out just like yours.. the only reason
I didnt hurt anything was that they went into
coil bind before the valves hit.. that was just
like running a rev limiter

Mike you suggested checking the springs a couple years ago on this thing.
got lazy and only ck`d a couple.
Should have just got new ones.

See what this winter holds,maybe pull it apart and go thru it and make sure there isn`t more hiding stuff.
The heads are un-ported as is the intake.

Without knowing what electronic ignition box you have on there I hope you didn’t get your hands on one of the old mopar boxes that had a built in rev limiter in it. I fought that issue back in the 70’s.

MSD,,,tried 2 different ones,2 coils/distributors,,,1 chrome 1 orange MP box.

Good deal. That drove me crazy as we didn’t have info available like we do today. What’s funny is it was a 509 cam in a 340

If it where me I would go to a hydraulic roller and kill two birds with one stone.

Running an old hydraulic flat tappet cam is going to kill the engine. Just a mater of time. The oils and all the additive you have to run to keep them alive is not good.

Just my thoughts.

I could have saved you a bunch of trial and error, buddy!

That blower when I had had ZERO problems pulling my 446" motor to 5600-5800, I usually shifted right at 5500 tho. Cam was a Crower 282/292 (232/242 @.050 if I remember right or a little bigger than a Comp 280) on a 112 in at 107. I ran the old 933 Hemi springs, heck I still got the 906 heads laying around somewhere! something like 130 seat and 310 over the nose, most people run the comp 986's (if i remember the # right) that are like 110 seat and 285 over the nose.

But I don't think running a 108 Lobe spread 509 would be the way I'd go, way too much overlap so your effective boost will be even lower. I know Landy didn't recommend it for the blower, I had one on my shelf. He recommended a Crane split pattern that was just slightly smaller than my Crower but he told me my choice would work great, and it did.

That blower for what it was (to me) was very impresssive, I was able to take a basically stock compression high 12 second 440 bottom end and add 100+ HP with a swap that took less than 1 1/2 hours to do start to finish. this was the late 80's , no truly affordable Heads back then (except maybe the Iron-1's). I only ran an 850 on it, Landy told me when I bought it to put a 950 on it.

The Team G, Gary (RIP 180) used to crack up whenever I talked about That Manifold not being able to fall out of a tree below about 4000 rpm.

The only difference I can think of and it should be unrelated? is that my combo was a 4 speed.

I guess you considered fuel pressure or a restriction? Last time I saw a motor inexplicably laying down it was pick-up corrosion limiting flow....my friend didn't want to believe me until I dropped his tank and showed him.

Hey Bobby.
The .509 I have is 114c/l in at 110.
Ran a 224/234@114
and a 236/241@110

.509 was fastest with iron heads.
Haven't tried every combination with the aluminum heads yet.
Ran an 11.09@120 with the rpm issues.
Can't wait for next spring.
It should be quite a bit faster

11.09 @ 120 turning only 5100 is testament to the torque your putting to the ground. 500 more RPM and your running 10.70's at least

I was gonna say the wider 114 509 might work good to overcompensate the head restrictions.

I'd start with fuel, do you have a pressure gauge on it? if you feel it laying down it's likely fuel cause with a blower even with dropping boost it should still pull, just at a lower rate of pull but still harder than say a normally aspirated motor.

Yes pressure gauge.

I can jet up and loose MPH.

With the blower on it if you stay in it it can rev past 5,000 but you have to wait for it.
Probably put 50 passes on it at the track so far, a whole lot more on the road.
Shifting over 5,000 really kills the E.T.

Still thinking valve float or fuel flow. Boost doesn't just lay down like a rock it tapers

Try setting the seat pressures at 140 to 170 lbs. with no more than 400 lbs. open on your current broken in camshaft and matching lifters
On your deal those current low pressures are not seating the valves at the upper RPM, especially the intakes
Let us know your results afterwards please

Are you SURE on the lifter pre-load? What kind of rockers? How many turns past 0 lash? If you're 1 full turn past 0 lash thats .042 pre load assuming a standard 24 thread per inch adjuster. That could be too much for your setup. I'd try 1/2 turn (.020)

Put a solid cam in it with some real springs and be done with it.

IMO, the MP 933 spring is technically a better match for the 509 cam than the Comp 911.

My main gripe with the 911 is its way too far away from coil bind with most typical hyd cams.
Installed at 1.900, it's .200 away from bind at .500 lift, which is a little more of an invitation for spring surge than a spring with similar pressures, that's a bit closer to coil bind.

The MP 933 spring is fairly high rate, and is getting close to being maxed out at .500 lift.

There aren't many cams that I feel the 933 spring is a good match for, but the MP 509 and 484 cams are two that I feel are.

It i "had to" run a hyd cam, I'd use the Hy-lift B-2330S lifters adjusted at zero preload and a spring package set up for like 140/340.

A good read on the pitfalls of hyd cams and high rpm is the old Mopar Muscle article by Dulcich in 2005(iirc), "mild mannered mauler".

Have you tried a different set/brand of lifters? Had that issue years back and the lifters would pump up at RPM and it would just nose over on the top end.
.

The 1st build up in 11' had the Summit 6401 cam and Comp lifters.
Stock rockers etc.
2nd cam MP 509 MP lifters stock valve train.
3rd cam Comp 525 with Comp lifters and adjustable Crane rockers on Stage 6 heads,can't use stock rockers on Stage 6 heads.Pushrod end hangs over valve cover face.
4th combination MP 509 back in with Crower cam saver lifters.
Crane rockers.
I followed the instructions with the lifters,I will have to find the instructions and confirm my memory.
The RPM ceiling has been there through all the changes.

Same springs for all combos?

When you get tired of messing with it, you'll put a solid in it.

440, mild solid cam, Mancini rockers, single springs(140 on the seat);

Don't forget that the rocker ratio will end up making he valves open more than just the thread increase or decrease with the adjuster changes, which can affect the pressures on the lifters
I like to use right at 1/4 to 1/3 turn preload on 3/8 adjusters from zero lash at room temps. to start with and go from there with the motor broken in and warmed up

Yes,I had a .528 MP solid in mind,then I saw the new 114-c/l 509 and tried it.

I`m sure to some reading some of my posts on this thing, that guy is F++k== nuts OR stupid.
You would`nt be 1st to say so.

In my own defense I have NO ONE to talk over or bench race ideas with except forums like this. So yes I make mistakes and take the long way around sometimes.
It is what it is..............

I had it written on the board 1/2 from O-lash cold.

Something experiment with next summer.

Well couldn`t wait for spring,so installed a used set of Hughes 1106 dual springs I had on the shelf.

I left the open Weiand Team G on it,only installed the springs.

The damper in the single springs had destroyed the seat shims,not impressed by the debri in the pockets.

So anyway just springs NO other changes.

I was hoping it would pull higher but did not expect to see such a dramatic change.
Idles better,crisper
Throttle response is impressive.
Power everywhere from idle to 6,000 is smooth and am suprised just how good it runs for the wrong intake,jetted way rich=11.5 AFR,not enough timing for 8.8cr. and 3.33 gears.
My butt gauge says 11.80ish.

So the springs were it.
1,000 to 6,000 with no popping or nosing over.

If we get another stretch of good weather,I will install the blower and have at it.
Thanks for all the ideas and replies

I think the .528 would have been the better choice, but glad you found something that made a difference.

Next time its apart I`ll have to do some digging and see if a change is worth the money.

I have to remind myself that I`m bumping into the 10`s with NO rollbar and a 50 year old lap belt.

Really just trying to see what it can do,not looking to have 2nd race car that I don`t use.
10.999 sounds so much better than 11.000000

Glad to hear you found a issue.. so now its all
set.. right

Thanks

I hope so..... looking forward to trying the blower again.

My back is not happy with me for todays project.....setting the blower on probably would have put me down for a few days..sciatica..sux

Glad you found it,

Like I said I spun that little blower up to 6K several times with the old 933 springs, if you think about it, running easy 10's with a stock short block and unported heads in a 3700+ pound street car with mild gears is pretty impressive, I always felt like that little blower was like a '125 Nitrous shot' that I never had to refill the bottle for. I miss it, kinda sad sometimes I sold it but it went to very good hands!

Glad you figured it out Dennis!

Thanks Bob.
Now maybe I can keep up with you!