572 tall deck cam
 

Time to replace cam and valve train on my 572 tall deck. 8.5:1 comp. Merlin heads 320cc intake, 119cc combustion chamber. Dart single plane intake 1050 holley carb., gaffrig. Dry to tip headers. Current cam is a comp cams 288ar8. 680 lift solid roller 288 in. 296ex. Duration, 108 lsa. Dyno results 693 tq. @ 4,500 rpm. 672 hp @ 5,400 rpm. Happy to stay in this hp tq. Range. And solid roller or hydraulic roller is fine. Looking for cam, spring, lifter suggestions. This is in my Formula 402sr1 big and heavvy
thanks guys

why are you changing the cam and etc????? alot of hours???
i am running cam machine shop suggested. i guess shop has used before and like the cam
its an isky cam, red zones solid roller lifters, they , the shop , ordered all my parts,,as they know what will work.
140444861 heads, 380 runners,, they got the springs, so i dont know what they got,,,but they work..
cam is similar to yours 286 296 and 714 lift lobe center 114
547 's standard deck,,,10.3 srp pistons,,,single plane intake ,,,1050 dom's,,,old cmi split top headers...
i wish i had run motors on a dyno,,,but ,,,too late for that...
shop said motors should be around 675 hp.....
i also have an old heavy scarab...

good luck

Thanks Flashgordon, they were rebuilt and sat three yrs. before i bought and installed them last year found they had set one pushrod on top of the lifter instead of in the pocket. Damaged a lifter pushrod and rocker. While fixing that i
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found the cam had significant wear and weak or incorrect springs. So before any major damage time to do it right.

hmmmm,,,well with what these motors cost or money we have in them,,,its best to never second guess anything.
just more info the shop i go to builts all hi perf stuff...cars and boats.
only thing they dont do ,,,is flow heads, they do the basic head work..
good luck....

I haven’t used them, but I like the idea of bushing lifters. Less weight and low or no fallout from a failure that could take out an engine.

That is a lot of duration (288/296) and it start to fall on it`s face at 5000rpm?
That thing should pull till 6500+ , wonder what`s going on there.
Mine is blown ,548ci. 247/254 , still making power at 6200, stalls at 6400 , starts to drop off at 6500rpm.

Any chance that's to .020 number, not the .050.

Is the cam bearing journal all chewed up or am I seeing things ?

254 ...262 at .050 lifter rise

Probably wouldn't be bad if it was a hydraulic roller on a 112.

Jounals are fine. Several lobes have edges cut into lobes and what looks like stress cracks.

okay that makes more sense , 253/261 still shouldn`t be running out of steam so early thou .
Something `s not right

comp catalog shows 2 spring options on this cam this is the on i believe are in now
Camshaft Type
OEM
Camshaft Type
Roller
Quantity
Sold as a set of 16
Coated
No
Damper Spring Included
Yes
Number of Springs Per Valve
Dual
Valve Spring Style
Standard
Outside Diameter of Outer Spring (in.)
1.539
Position
N/A
Inside Diameter of Outer Spring (in.)
1.125
Spring Type
Double
Inside Diameter
0.731 in.
Outside Diameter
1.539
Spring Rate
490 lbs./in.
Inside Diameter of Inner Spring (in.)
0.731
Manufacturer's Part Number:
26097-16
Shipping Weight:
5.71
Package Height:
3.7
Package Depth:
2.9
Package Width:
13.5
The other is 734 lb. In Pressure
my thought is it needs the bigger spring.

Camshaft Type
Hydraulic
Camshaft Type
Mechanical
Quantity
Sold as a set of 16
Coated
No
Damper Spring Included
No
Number of Springs Per Valve
Dual
Valve Spring Style
Standard
Outside Diameter of Outer Spring (in.)
1.57
Position
N/A
Inside Diameter of Outer Spring (in.)
1.12
Spring Type
Double
Inside Diameter
0.796 in.
Installed Height (in.)
1.95
Installed Pressure (lbs.)
190
Open Height (in.)
1.2
Open Pressure (lbs.)
747
Spring Rate (lbs./in.)
743
Outside Diameter
1.57
Spring Rate
753 lbs./in.
Inside Diameter of Inner Spring (in.)
0.796
Coil Bind Height
1.1 in (27.94 mm)
Manufacturer's Part Number:
944-16
Shipping Weight:
5.58
Package Height:
13.6
Package Depth:
2.9
Package Width:
3.7

merlin 320 heads,,those heads suck.
you'd be better off w/ cheap chinesium heads or EQ320's.

That's great but you're running a 572

Guessing not enough spring pressure and the lifters are bouncing off of the lobes. Could be the pushrods flexing. Maybe call someone like Bullet, tell them what you want to do and have them spec the cam, lifters and springs.

i agree, but not in the budget right now.

if you are talking about the red zone isky lifters,,yes i was told them are bullet proof....
but they are taller than normal lifters.
i found this out the hard way ,,,lifters were crashing into my intake valley baffle ,,,destoyed it baffle
i caught it before got really bad ,,,thankfully mu eix filters caught all the metal.
i did a post on this.
so i removed intake valley baffles.
https://cimg9.ibsrv.net/gimg/www.off...77c0339d06.jpg

How in the heck does this even happen ^^^^^ who assembled the engine ?

Glen Self Racing Ok. They replaced the lifters, but. I cannot believe anyone would reuse that cam. I haven't spoke with them so i don't know if it was their decision or the owners. Also had a cracked head and then not setting the pushrod in the lifter pocket. I heard nothing but good about these guy's prior to buying this engine from a private party. But i am not impressed with any of their work on this motor. But the motor was rebuilt 3 yrs ago then sat till i purchased it. So move on and fix it right.

The lifter baffle clips in at the bottom head just below the intake ports at least 2inches above the lifter its self, so how did the holes happen ? just trying to understand I know your moving on

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speedy,,if your talking about the intake baffle...i assembled motors.

as i was rotating motors on stands ,,setting valve lash,,,i heard a noise ,,i kept spinning motor over , then figure out lifter was hitting baffle.


took baffles out , placed on top of 3 dia pipe, and peened the baffles in area was hitting.

put back on motor,,,rotated motors several several several times,,,didnt hear or fell anything hitting.

i discover the issue on the port motor, as i cut open my filters and found metal in my wix filters,,but nothing really got pass filters.

stbd engine baffle was fine.


so i boiled block, new rings bearing in motor with bad baffle.

my machine shop person said he has never seen anything like this

speedy ...look ar the lifter in photo...the isky red zone are taller lifters

Do not try to use the baffle again, first thing I do when working on these engines is to remove and never reinstall them. not just because of the lifter situation that you have encountered, but with the cool lake water keeping the engine running cool I have seen water (condensation ) accumulate on the pan and run down and drip on top of lifters causing premature failure. The benefit of this outweighs the original reason of their purpose, to keep the hot oil from the underside of the intake. jmho

Geeez. I have never seen anything like that.....................if you're running an intake manifold with a center located PCV like the 500 & 525 EFI intakes you need to run the baffle, or risk the chance of sucking oil into the upper plenum and into the cylinders.

I have removed them from my friends 500 EFI engines when we rebuilt them and never had a pcv/oil burning issue. those engines have been running fine for the last 6 years. and my engines since i built them 20 years ago,but like i said that's just my opinion, works for me. but I do see your concern!

my motors are 10051107 mark 4 bow tie block and the 14044861 bow tie heads.....
i removed baffles in both motors ...do not see any other issues
dont really know anything about 525 efi motors....
i have no pvc stuff in center of heads of intake
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sorry ,,,i am old school,,

I was just making a general statement about the valley pan, not pointed at anyone

np speedy.....

no issues taken ,,
life is tooo short for silly issues..
just like to get info learn, chat, etc...

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Is that a hole in the guessing #6 intake port floor ?

Dont spend a dime repairing those heads. There’s another 100hp in there with modern heads and compression. Assuming you’ve got a good exhaust system. What is your exhaust setup?

gaffrig headers dry to the tip. My mechanic caught the head while test firing and prior to dropping the motors in so i had him replace it at that time. Would have loved to put better heads on at that time. But after replacing everything in the bilge i was already way over budget and out of money. Like any good boater lol. So the goal is to work with what i have but replace the cam and valve train.

its a thread hole for the extra head studs that get used if the block has the bosses.

I ran the extra bolts with the Big M block and multiple sets of heads, never saw them come through the intake port. Maybe I was just lucky, seems like a great place for a vacuum leak.

It needs to or should be plugged from the bottom side when not used.

that hole is plugged from under side....
didnt the old ZL1 aluminum block have the extra stud hole???

The Brodix heads that I used were tapped for studs, the holes never came all the way through. I believe the stud kit came with the Big M blocks. Different manufacturers do things differently I suppose.

Have Bullet Regrind that Cam , a whole lot cheaper and just as good .