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Author Topic:   need some help, SAD 428 numbers - dyno
Randy
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Posts: 43
From: Newriver,Az. U.S.A.
Registered: Nov 2000

posted 04-20-2003 04:36 PM     Click Here to See the Profile for Randy   Click Here to Email Randy     Edit/Delete Message   Reply w/Quote
This is pathetic, don't know what's going on. Here's some spec's, where do I start looking? Have a 428 bored .030, stock rods, forged slugs w/ 9.85:1, edelbrock heads w/ 2.19 in.- 1.72ex, flow 300-240 at .700, Schnyder hyd. flat tappet w/ 230 @ .050 both sides, .525 lift-110, dove valve train,edelbrock rpm intake, holley 800 dbl. pump, FPA tri Y headers,2 1/2 pipe w/ flowmasters, 3.25 trac loc 9", C-6 built, 2500 stall. Just looking for a fun street car that could run in the low 12's- high 11's. So after a best of 13.1 at 104, I went for a dyno tune session. Put the car on the scope for a check, looked good. 36deg.timing all in by 2500, MSD6al, duraspark dist. Car on a mustang dyno put out 262hp at4891rpm and 472ft lbs. at 3127rpm with OPEN HEADERS. Tried a new holley 950hp series and gained 4 hp. No one could say why the numbers are so low and peaking at 4900. It would make a great truck motor for hauling cattle but a huge disappointment to me. I know these are not race car parts but my hp #'s are 302 #'s . My only thought is it can't breathe but wheres the plug?

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Hans olsson
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From: Sweden
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posted 04-20-2003 05:11 PM     Click Here to See the Profile for Hans olsson   Click Here to Email Hans olsson     Edit/Delete Message   Reply w/Quote
Weak valve springs or wrong preload on the lifters.Or maybe the intake centerline.
Lets hear the numbers.

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[This message has been edited by Hans olsson (edited 04-20-2003).]

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Moneymaker
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From: Lyons, IL, USA
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posted 04-20-2003 05:28 PM     Click Here to See the Profile for Moneymaker   Click Here to Email Moneymaker     Edit/Delete Message   Reply w/Quote
I don't like that cam, but I would try fooling with the lash. You may have too much lifter plunger depression.
Also, you don't have near enough timing. FE's lie a minimum of 38 degrees.
Most HP applications are set at 42 degrees.

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Alex Denysenko
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Mpcoluv
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From: Charlotte NC usa
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posted 04-20-2003 06:45 PM     Click Here to See the Profile for Mpcoluv   Click Here to Email Mpcoluv     Edit/Delete Message   Reply w/Quote
472 ft/lbs with 262 hp?
Something is odd there....

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methylated
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Posts: 43
From: wytheville,va usa
Registered: Mar 2003

posted 04-20-2003 07:03 PM     Click Here to See the Profile for methylated   Click Here to Email methylated     Edit/Delete Message   Reply w/Quote
how well are the rings sealing ? what sort of piston/ring combo you runnin ,and how were the cylinder walls honed?

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Moneymaker
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posted 04-20-2003 07:15 PM     Click Here to See the Profile for Moneymaker   Click Here to Email Moneymaker     Edit/Delete Message   Reply w/Quote
It's in the cam.
Either the push rods are too short, or the springs are coil binding, or......?
It's not seeing anywhere near the .525 lift.
Or.......the chassis dyno just wasn't calibrated to spit out the numbers the operator wanted it to.

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Alex Denysenko
Co-Administrator and Moderator

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Quote #1: "I never met a magazine mechanic I liked."
Quote #2: "Make sure brain is in gear before engaging mouth!"
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steve'66
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From: Sonoma,CA,USA
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posted 04-20-2003 07:17 PM     Click Here to See the Profile for steve'66   Click Here to Email steve'66     Edit/Delete Message   Reply w/Quote
The "plug" could be the exhaust system. Can you run it at the track with open headers?

SteveW

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Moneymaker
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posted 04-20-2003 07:37 PM     Click Here to See the Profile for Moneymaker   Click Here to Email Moneymaker     Edit/Delete Message   Reply w/Quote
Those Tri-y headers are at least as good as CJ manifolds Steve. All of my CJ cars that did not have headers were very strong with nothing but 2.5 open dumps.

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Alex Denysenko
Co-Administrator and Moderator

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Quote #1: "I never met a magazine mechanic I liked."
Quote #2: "Make sure brain is in gear before engaging mouth!"
Quote #3: "If you can't run with the big dogs, stay on the porch!"
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afret
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From: Lancaster, CA
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posted 04-20-2003 10:12 PM     Click Here to See the Profile for afret   Click Here to Email afret     Edit/Delete Message   Reply w/Quote
I think Alex is right about the inital advance. You should be running more initial. Also, why are you running such large valves? 2.09/1.66 valves should be more than adequate. If I recall correctly, the Ed heads have the intake valve offset about .05 to the outside with the exhaust at the normal low riser position. That would put the intake valve very close to the cylinder wall with a 4.16 bore. The large exhaust valve will also be close. Did you chamfer the top of the bore for clearance and unshrouding and check piston to bore clearance? Just something to think about.

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jkilroy
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From: Vicksburg, MS
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posted 04-20-2003 10:21 PM     Click Here to See the Profile for jkilroy   Click Here to Email jkilroy     Edit/Delete Message   Reply w/Quote
Alex is right, something is not right with that cam. Did you fully degree that cam when you installed it? Sounds to me like that puppy is way advanced. I would get out degree wheel and dial indicators and figure out *exactly* what is going on under those valve covers.

Also, Mr. Olsson's comment about the springs has merit. Though I am not familiar with you're particular grind, 120lbs on the seat and 305 or so across the nose sounds about right. How is your idle? What kind of numbers do you get when you put a vacuum gauge on it?

Unrelated to you're dyno numbers though it may be, I think you are going to need more gear to let the heads and cam work. Doubly so if you are dead set on keeping the 800 pumper carb.

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Jay Kilroy
68' Fastback GT 390
"No such thing as a cam thats too big"

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65_289
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posted 04-20-2003 11:08 PM     Click Here to See the Profile for 65_289   Click Here to Email 65_289     Edit/Delete Message   Reply w/Quote
Mustang dyno's almost always dyno lower than a Dynojet. So keep that in mind too.

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Randy
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From: Newriver,Az. U.S.A.
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posted 04-21-2003 12:23 AM     Click Here to See the Profile for Randy   Click Here to Email Randy     Edit/Delete Message   Reply w/Quote
I appreciate the input guys and will try to take it all in. First off,I make my living breaking colts and shoeing horses and have for 18 yrs.I don't build motors thoughI have done as much work on this car as I possibly could and love it.I had the motor built at a motor shop so I would have a package that works together good, right? Here's what I think I know. The cam was degreed in, the spring pressure is right where your'e saying,I don't know where lifter pre-load is. That I can check, should I do it hot or cold? Why the big valves I don't know. A motor guy says we can do this, this, and this to these heads and you'll be real happy with them. O.K. sounds good, only thing is , it's not working. So now I know somethings not right ,since I'm running it but not while they're telling me how it's going to be.I'm not dead set on the holley 800, I am dead set on the gears. I like to drive to N.M. or Cal. now and then. Vacume is wierd too, I get 5 in. at idle - 900 rpm and it immediatly climbs with throttle and just keeps climbing up to 20in.still at3500-4000 but thats without a load on the motor so I don't know how accurate that is but it seems strange. Ring are speed pro file fit, Fed. mogul forged piston, don't know about the hone but I'm not using much oil, have maybe 400 miles on it. Hope I don't give the wrong numbers here, intake center line is 108, lobe sep. is 110, rocker ratio-1.75. Alex, I've read you don't like giving cam advice but you're talking to a greenhorn here, I could use advice from somewhere. Whats the biggest I could use and still drive to N.M.? None of it makes sence. I don,t think getting 400 rwhp out of a 428 should be a long reach.

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Moneymaker
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posted 04-21-2003 01:20 AM     Click Here to See the Profile for Moneymaker   Click Here to Email Moneymaker     Edit/Delete Message   Reply w/Quote
Let's start out by fixing the problem you have Randy.
I would loosen the rockers on bank at a time running until they just click a bit and tighten them there. Then let's see what you have for vaccum and power.

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Alex Denysenko
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Quote #1: "I never met a magazine mechanic I liked."
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Rory McNeil
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posted 04-21-2003 04:59 AM     Click Here to See the Profile for Rory McNeil   Click Here to Email Rory McNeil     Edit/Delete Message   Reply w/Quote
I`ve had a few 428 CJ Mustangs, running between 11.9 & 12.5 ET`s, and I relly can`t see you getting into the low 12`s with a 3.25 gear with what you have. For having aluminum heads, your compression is a bit low, although your cam isn`t too big, I think it`s big enough that you are losing some cylinder pressure, though. Although I MUCH prefer solid lifter cams on my own FE`s, hydraulics can work OK, BUT too much lifter preload will make it "doggy". Although the FPA Tri y`s are supposed to fit earier, I still prefer the Hooker 6114`s, I`ve always had good luck with them. As for the heads, I don`t know if you are going to really see much improvement from those larger valves, due to their close proximity to the cylinder walls, which may cause shrouding. The stock 2.09& 1.66" valves in my basically stock C8OE-N 428 CJ heads are sufficent for low 10`s @ over 131 mph in my 428 Fairmont. The S/S 428`s run well into the 9`s with the smaller valves as well.

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78 Fairmont 428 4 speed [email protected]
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Daniel Jones
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posted 04-21-2003 12:16 PM     Click Here to See the Profile for Daniel Jones   Click Here to Email Daniel Jones     Edit/Delete Message   Reply w/Quote
> 472 ft/lbs with 262 hp? Something is odd there....

Indeed. 472 ft-lbs at 3127 RPM is 281 HP.

Dan Jones

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ZEATER
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Posts: 173
From: Mount Pleasant,IA,USA
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posted 04-21-2003 12:49 PM     Click Here to See the Profile for ZEATER   Click Here to Email ZEATER     Edit/Delete Message   Reply w/Quote
I was told by the chassis dyno I take mine to that an automatic with high stall will fool the dyno into showing lower horsepower numbers but accurate torque numbers. A friend of mine with a Cuda and 3500 stall showed 260 horse and 415 torque on a chassis dyno. His car runs 11.85 in the quarter.

They said in the case of an automatic the chassis dyno is used more to map increases or decreases from a starting point. I don't know if this is the same for all chassis dynos but you could ask the shop.

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Randy
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From: Newriver,Az. U.S.A.
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posted 04-21-2003 05:10 PM     Click Here to See the Profile for Randy   Click Here to Email Randy     Edit/Delete Message   Reply w/Quote
Something I forgot to mention, that I did do a compression test. I got 100-120 on 7, 130 on 1. I did this with the motor cold ( plugs are a bitch to get to in that 67). Seems low but I don't know what it should be. I'm going out this afternoon and try to check If I'm getting .525 lift. I have a dial indicator and will check at the rocker and see if I can compute it. I'll also do the rocker adjustment and see if it's tight and up the timing to 42 and see how it is. I'm trying to be ready to drive this thing to Cal. this weekend, there's an all ford show at Knott's berry farm I've planned on all year so I don't want to go out and rip the motor out right now. Thanks for the help

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johnmustang
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From: British Columbia , Canada
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posted 04-21-2003 07:50 PM     Click Here to See the Profile for johnmustang   Click Here to Email johnmustang     Edit/Delete Message   Reply w/Quote
quote:
Originally posted by Randy:
Something I forgot to mention, that I did do a compression test. I got 100-120 on 7, 130 on 1.


That seems awfully low, I would have thought that you would be up in the 165 to 180 or something like that. I assume your 428 is pretty fresh, even for a tired 428 I think your readings are way to low. I could be way wrong about this, but will wait and see what the guys with more experience than I have say about these numbers.

JOHN

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65 2+2 FASTBACK
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Moneymaker
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posted 04-21-2003 08:54 PM     Click Here to See the Profile for Moneymaker   Click Here to Email Moneymaker     Edit/Delete Message   Reply w/Quote
The cranking compression is low due to the cam.

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Alex Denysenko
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Quote #1: "I never met a magazine mechanic I liked."
Quote #2: "Make sure brain is in gear before engaging mouth!"
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Mike_R
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From: Indianapolis, IN 46237
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posted 04-22-2003 09:01 AM     Click Here to See the Profile for Mike_R   Click Here to Email Mike_R     Edit/Delete Message   Reply w/Quote
This may not be anything, but we might as well cover all the bases. What brand of stall convertor does it have? Sometimes a low dollar/crappy stall convertor can kill the performance and this was a rear wheel dyno, so I guess it's worth asking the question.

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Dusty Kiser
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Posts: 168
From: Bethel,Oh USA
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posted 04-22-2003 09:33 PM     Click Here to See the Profile for Dusty Kiser   Click Here to Email Dusty Kiser     Edit/Delete Message   Reply w/Quote
Just a few thoughts that probably won't add much to what Alex and the others have offered, but It's extremely hard to give good advice without good input. When performing a compression test the intake (carb) needs to be open so there is no restriction to airflow. All the plugs should be out so engine turns freely and does NOT pull fuel charge into cylinders. Five or six revolutions is sufficient. Also, as to vacuum, sounds like you are connected to a "signal" port and not manifold vacuum. Try teeing into the pcv port or similar manifold vacuum port. As for your horsepower numbers, your strip times told you what your power level was. The only advantage I can see in a dyno pull is if you tried numerous changes on back to back pulls to see what the engine liked. Recheck your numbers, try bumping the igniton till you get spark knock, then back off some, then write back and let us know where things actually stand. By the way, when you pulled the plugs what did they look like? Good luck with it and don't get frustrated. It always takes a little while to work out a new combo. Oh, as for coil bind, if you bought the heads preassembled from Edelbrock, they should be OK with that cam, and if they are binding you probably have a basket full of bent pushrods. At least that was the achilles heel of my 428.

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Randy
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From: Newriver,Az. U.S.A.
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posted 04-23-2003 12:46 AM     Click Here to See the Profile for Randy   Click Here to Email Randy     Edit/Delete Message   Reply w/Quote
Here's what I came up with. 310 lift on the pushrod, rocker was off so with ratio of 1.7 gives .527, right? The dove rockers are 1.75. Springs are new and came with the cam, just by watching them theres no chance for coil bind. I reset all the rockers, all were close. Yes, I had checked vacume at a timed port, checking it where the pcv hooks in showed 8 in. at idle and immediate increase wih throttle up to 19 in. with a decrease to 15 in. by 5000. I have no idea what to make of that. Plugs look good, the dyno guy checked them too and agrees. Compression test was with all plugs removed and wot. I don't see anything out of wack with the valve train or anywhere else for that matter but I don't know what all to look for. Surely that combo is capable of more than that, isn't it? The converter is a Hughes-2500. How many of you have checked out Doves website and their story of edelbrocks intake verses theirs. They are claiming huge power gains. Any experience with Dove's intakes? How about Offy's port-o-sonic. Yeah, I'm reaching but Dove's claim is incredible and sounds very similar to my situation. What else can I look at? If this is all this package is capable of then this motors coming out, I started this project 2 yrs. ago and damn sure did not have a 260hp goal in mind.

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Mario428
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posted 04-23-2003 06:17 AM     Click Here to See the Profile for Mario428   Click Here to Email Mario428     Edit/Delete Message   Reply w/Quote
The Dove intake would be a huge mistake on your car. It was on mine and my car has a lot more stall and gear than yours.
Your cranking compression is seriously low. My 428 is about 9.5 to one and I had 130PSI cranking with a [email protected] cam. Your 230 cam should be a bunch higher. Pain in the ass but I would check cam timimg, yours sounds retarded big time to bleed off that much cranking compression.

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Butch Jennings
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posted 04-23-2003 11:12 AM     Click Here to See the Profile for Butch Jennings   Click Here to Email Butch Jennings     Edit/Delete Message   Reply w/Quote

I wouldn't do business with Jim Dove again. I had some serious trouble with him a few years ago, when I raced an FE in my car, and he was a real pain to try and get things resolved. If I found his stuff used and cheap, I might buy it, but most of his stuff isn't worth the money he gets or the trouble of dealing with him IMO. Edelbrock's stuff is all killer stuff, I doubt that Dove makes an intake that can make more power than a Victor. I can tell you that on my 460, the Victor makes better power than a tunnel ram with a couple of different carb combinations.


Sorry but I don't have much to add for your lack of power, your combo doesn't sound bad to me. I don't like the tri y headers, but it seems to me that 230 @ .050 is gonna be a dog with 3.25 gears and a tight converter.

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Butch
460 powered 1967 Comet Cyclone (Broken)
10.271 @ 130.231
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n2oMike
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Posts: 2419
From: Spencer, WV
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posted 04-23-2003 11:43 AM     Click Here to See the Profile for n2oMike   Click Here to Email n2oMike     Edit/Delete Message   Reply w/Quote
13.1 is pretty good for a 3.25 gear and 2500 stall converter in a street weight vehicle.

By the way, what type of vehicle is it, and what does it weigh? Did you use slicks? How tall?

Mustang dyno do report significantly less power than the Dynojet. They are supposed to be far more accurate. Converters and automatics do indeed show less power in chassis dynos than manual setups.

I would do a Alex suggested, and back the rockers off until they start to click, then tighten them down just enough (around 1/4 turn) to keep them quiet.

As for next steps, I'd install a solid cam, Hooker headers, and larger exhaust.

Oh, were you running the exhaust at the track? If you were, a crush bent 2.5" exhaust will slow a built 428 down quite a bit.

Re-do the lash.

Good Luck!

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Mike Burch
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3
http://www.geocities.com/carbedstangs/cmml_mburch.html
http://www.fortunecity.com/silverstone/healey/367
http://www.mustangworks.com/cgi-bin/moi-display.cgi?220

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afret
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posted 04-23-2003 01:50 PM     Click Here to See the Profile for afret   Click Here to Email afret     Edit/Delete Message   Reply w/Quote
Just wondering how your dizzy is set up. How much inital advance are you running and how much mechanical advance do you have? Did you try kicking up your timing a few degrees? What's the elevation where you're at and where you tested your car? I guess you are in Arizona. If you are anywhere as high as Flagstaff, you would lose a lot of power. 13.1 sec isn't a bad time but your mph seems low for what you have.

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Randy
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From: Newriver,Az. U.S.A.
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posted 04-23-2003 06:03 PM     Click Here to See the Profile for Randy   Click Here to Email Randy     Edit/Delete Message   Reply w/Quote
The car is a 67 mustang fastback, I don't know what it weighs. Tires are 295/50-15 nitto drag radials. I have reset the lash, valvetrain looks good to me. 13 sec. may be good for a small block street car but no way for this. the issue is 472lbs. ft. torque at 3127 rpm and 262hp at 4891 rpm. Thats with open headers, with pipes attached it was only 10 hp less. With another 125 rwhp peaking at 5500-5700 ,low 12-high 11 would be easy, 3.25 ratio or not. This combo should peak in that range, it's not. RWHP should be at least 330 if not more.BOO HOO. Yeah, I guess the next thing to check is cam timing and I'll get on that. Something has to be off, I can't believe thats the limit of this package and if it is then it's all coming out. This is bull****. Let's see, timing is 16 initial, 38 total, all in by 2500rpm. This is bull**** still. I asked for and was told that my motor package would be a 500 hp package. Time to start over.

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n2oMike
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From: Spencer, WV
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posted 04-23-2003 07:58 PM     Click Here to See the Profile for n2oMike   Click Here to Email n2oMike     Edit/Delete Message   Reply w/Quote
One more thing to check is the valvespring INSTALLED height. Even if they are the correct springs, if they aren't installed at the correct height, the won't have the right pressure.

Most valvespring rates are around 300lbs/inch... so you're losing around 30 pounds of pressure for every 0.100" inch too high they installed. For example, if they are supposed to be installed at 1.800" to give a seat pressure of 120lbs, installing them at 1.900" only gives 90lbs of seat pressure.

Setting spring height is a VERY important, but often overlooked step in setting up the valvetrain. Using the different valves (which may be longer than the stockers) can aggrivate the problem.

I agree, it should NOT fall off at 4900 rpm.

Check it!

Good Luck!

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Mike Burch
66 mustang real street
302 4-speed 289 heads
10.63 @ 129.3
http://www.geocities.com/carbedstangs/cmml_mburch.html
http://www.fortunecity.com/silverstone/healey/367
http://www.mustangworks.com/cgi-bin/moi-display.cgi?220

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steve'66
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posted 04-23-2003 08:44 PM     Click Here to See the Profile for steve'66   Click Here to Email steve'66     Edit/Delete Message   Reply w/Quote
Where's my buddy Glen?

His '67 GT, 428 runs low 12's with a 4 speed and street suspension at Full Weight, nothing fancy in the suspension department. I think 112+ mph in the 1/4.

Glen, what are the spec's of your motor?

SteveW

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Randy
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From: Newriver,Az. U.S.A.
Registered: Nov 2000

posted 04-29-2003 08:14 PM     Click Here to See the Profile for Randy   Click Here to Email Randy     Edit/Delete Message   Reply w/Quote
What a weekend. Good advice on checking installed spring height and valve length, I will check on that. Before I went to Cal., I tore down to the timing chain and saw that it was set up 2+ and looked good. It is a JP billet set-up, multi index. So off to Cal. thinking I'd be o.k. On the way back, about Riverside, one of the new dove h.d. rocker shafts broke and a lifter came out. After spending the night in the back of a 67, an hour of phone calls produced a set of shafts, gaskets from auto zone, and my ever present tool bag, I was back on the road home by 2:00. Much thanks to Gary Richards in Riverside for the help and parts. At this point , I'm calling this motor a misbuild and it's coming out again and I hope to work something out with the builder. My next project will definately have a crate motor, no more of these custom builds.

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Mpcoluv
Gearhead

Posts: 1278
From: Charlotte NC usa
Registered: Apr 2001

posted 04-30-2003 07:17 AM     Click Here to See the Profile for Mpcoluv   Click Here to Email Mpcoluv     Edit/Delete Message   Reply w/Quote
Breaking a shaft? A billet shaft?
Are all the shaft hold down bolt holes in the edelbrock heads drilled and tapped deep enough? Is the shaft in some sort of bind?

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Rustang
Gearhead

Posts: 733
From: Clarion PA
Registered: Nov 2000

posted 04-30-2003 04:43 PM     Click Here to See the Profile for Rustang   Click Here to Email Rustang     Edit/Delete Message   Reply w/Quote
quote:
Originally posted by Mike_R:
This may not be anything, but we might as well cover all the bases. What brand of stall convertor does it have? Sometimes a low dollar/crappy stall convertor can kill the performance and this was a rear wheel dyno, so I guess it's worth asking the question.

That's a good point. One time I put a no-name 8" converter in my car and went 12.20's at 110. The next weekend I put my 10" TCI in and was back to 11.40'[email protected] It's very possible then that you're not seeing all your motor's power at the wheels. I'd be curious how much of the motor's RPM was lost thru the converter?

You're losing 19hp from where peak torque occured(3127rpm) to 4891rpm. That ain't right!
(I don't think an intake's gonna cure this problem unless there's a rag stuck in the old one! There's something more fundimentally wrong here than just a poor combination of parts. A motor just don't drop off horsepower after max torque occurs. Bad drivetrain loss, poor spark, serious valvetrain problems. Cranking compression sounds in the ballpark when comparing it to my truck's 460 with similar compression and cam)

Don't give up!

[This message has been edited by Rustang (edited 04-30-2003).]

[This message has been edited by Rustang (edited 04-30-2003).]

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Randy
Journeyman

Posts: 43
From: Newriver,Az. U.S.A.
Registered: Nov 2000

posted 05-03-2003 10:10 AM     Click Here to See the Profile for Randy   Click Here to Email Randy     Edit/Delete Message   Reply w/Quote
Since the shaft broke, some friends and I have been checking out the whole valve train set-up and I can't believe what we found.The whole rocker ass. is dove, the builder put 3/4 by 1/8 round washers under the stands to shim them up, here's why. The part number for the spring says it's for a mech. roller cam, 190 seat pressure, 370 open. With an installed height of 1.966, seat pressure is 160-170, we tested this with a simple on the head lever tester so it's in the ballpark. The cam card clearly list the proper spring part # and pressures, it calls for 110-120 seat,310 open. Doves's assembly is rated at 350 spring pressure without the end stands which is my set up cause I never expected high spring pressures. So the guy puts in huge springs, shims up the stands with washers and uses the stock pushrods. Well the motors out now so time to make some changes. This is the second build in 1 1/2yrs, the first one being much worse. I got a short rope and a tall tree for these pro motor builders, everyone knows all the tricks and just how to build the perfect motor, no problem, trust me. The mistakes I see are high school shop mistakes. What the hell happened.

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TomP
Gearhead

Posts: 5761
From: Delta BC Canada
Registered: Dec 99

posted 05-06-2003 11:23 PM     Click Here to See the Profile for TomP   Click Here to Email TomP     Edit/Delete Message   Reply w/Quote
There should NEVER be washers under the rocker stands. Valvetrain geometry needs to be proper to work.

I run about 350lbs open pressure on a hydraulic with stock rockers/shafts/stands in my 428 and it never busts anything at 6500rpm.

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