Need help choosing 454 cam

[KerrLake]

I'm in the middle of having my 370hp 454 rebuilt. I want to make sure I get the right cam. I'm using the same crank, boring, re-working heads. The shop looked up their marine cams and did not have many choices. One was .505 / .515 and the other was .525/.525, both Comp cams. Thanks for any suggestions.
BP

[Cuda]

The previous owner of my Formula said it has Comp 292H cams in it. Runs great, and idles great. It has been punched to 468, and raised compression.

[mrfixxall]

comp cams 262hworks well,,,but the isky 270/280 rocks....made over 500 hp on the dyno compared to the comp 262..specs as follows

part # 396271/281-14

lift
I .543
E .565

duration

I 270
E 280

duration at .050

I 221 deg
E 232 deg

lobe center

114 deg.

we zero decked the block,, used the stock style pistons,, used the stock exhaust valves and cut the heads for .221 intake valves.. mild port job blended the bowls ans blended the intake runners..and we used a rpm airgap intake...
509 hp and 612 ft lb of torque at 5200 rpm on 93 octain....

[Barry Eller]

Depends on how you use your boat. Lots of idle speed, low speed running, go with a mild cam. If maximum HP and torque is what your after, just make sure you have the fuel delivery system and exhaust system that will let it "Breathe".

Here is the link to the Company I bought my Comp cam and parts.
They have a good selection, designed for marine applications.

The Comp Cam Kit I bought is part number 295-012008k

http://www.cpperformance.com/products/Engine_Parts/comp-cams.htm

I'm putting a Comp HYD Roller back in my 502.

intake duration 286...@.050 226

exhaust duration 294...@.050 234

intake lift .591

exhaust lift .601

112 lobe separation

I'll also be using Comp HYD roller lifters, Comp Roller rockers, Comp's best push rods and Comp guide plates. (trying not to have a weak link!)

I have a good exhaust system, so reversion (water entering the engine from exhaust pulses when two valves overlap and are open momentarily at the same time) won't be a problem. But I wouldn't suggest a cam like this unless you have good exhaust.

[KerrLake]

Thanks for the posts. After the transom and stringer work, the new interior and engine rebuild, I must wait on the exhaust. Anyway, if I go too wild on my cam am I shooting myself in the foot with the 3" stock exhaust? I like to cruise around 3500-4000 with the wide open for a mile here and there. I know that the z-25 will not be a speed demon. However, while the engine is torn down completely, I want to get the best bang for my buck.
Brian

[Barry Eller]

Thanks for the posts. After the transom and stringer work, the new interior and engine rebuild, I must wait on the exhaust. Anyway, if I go too wild on my cam am I shooting myself in the foot with the 3" stock exhaust?
Brian


Yes.

Sorry.

Go as close to the stock cam profile as you can... Ah, fudge and go up a little bit, just a S-M-ALL amout...I always do...just don't go too far.

Just make sure to match your valve springs to the cam. (Coil Bind #'s):bonk:

[RickR]

KerrLake
You might want to read Dennis Moore's Big Block Chevy Marine Performance before you decide on a cam.

$50+Shipping
New in box
Not responsible for cam failure during break-in.

[KerrLake]

Rick R it seems Dennis Moore's Big Block Chevy Marine Performance is out of print and hard to get a copy. Is the picture you posted a stock cam profile?
My mechanic is going to guage to see what profile I have. He doesn't have all the marine books. What problems could I have with a little more aggresive cam if I don't do the exhaust now. I have the high rise manifold and quadra jet carb.

[RickR]

Stock Gen IV 454 Mag cams are
224/224 w/5.10 lift 115.5 LSA

Too large a cam will cause reversion and /or coil bind.

The Bullett cam I have is a warranty replacement I got because of a cam failure during break in (too stiff a spring). Please read http://www.cranecams.com/pdf/548e.pdf

I was using this cam in my 22, 454Mag Gen IV, w/Gil Mag Choice exhaust.

I will be working a fundraiser for Cystic Fibrosis untill Monday www.Curefinders.com

[mrfixxall]

comp cams 262hworks well,,,but the isky 270/280 rocks....made over 500 hp on the dyno compared to the comp 262..specs as follows
part # 396271/281-14
lift
I .543
E .565
duration
I 270
E 280
duration at .050
I 221 deg
E 232 deg
lobe center
114 deg.
we zero decked the block,, used the stock style pistons,, used the stock exhaust valves and cut the heads for .221 intake valves.. mild port job blended the bowls ans blended the intake runners..and we used a rpm airgap intake...
509 hp and 612 ft lb of torque at 5200 rpm on 93 octain....

Kerrlake, this cam uas used in a 454 370 hp,,when i installed the engine in my cust hallett 21 it had a volvo 290..i used the stock volvo exhaust also on his boat because he didnt want to spring the extra 1700.oo on some emi thunder exhaust...their was no reversion with this cam what so ever...

[KerrLake]

Thanks Mr. Fixall. Would this cam need a higher idle speed or should be ok with the recommended stock setting. Also would I have to rejet the carb from the stock settings? Any other problems I may encounter? Should I use an oil baffle too?
Brian

[KerrLake]

I talked to my mechanic today. I showed him the ISKY profile and the other things done to achieve the 509 hp. He said no problem. If I use the RPM airgap will I be able to use my stock carb, or will I that not work? He had a 454 in with the RPM airgap and showed me how he had blended and ported. It makes much more sense now.

[mrfixxall]

Thanks Mr. Fixall. Would this cam need a higher idle speed or should be ok with the recommended stock setting. Also would I have to rejet the carb from the stock settings? Any other problems I may encounter? Should I use an oil baffle too?
Brian


The boat already had a holly on it,800 cfm ...on the dyno i bumped up the primary jet from 80 to 84 and the secondary from 88 to 94...i also installed a 50cc accelator pump on the primary and left the secondary stock..i also took the accelator squirters from 31 to 36.....this cam sounds real healthy and is real responsive...if you plan on buying a airgap they only come in either a q-jet style or a square boar style(holly or carter or edlbroch) its not like a performer where its drilled for either carb...if your looking for the same style intake as a airgar theirs another copany thet makes the same style intake,, go to professionalproducts.com and look up the crosswind intake..
its cheeper then a airgap and it has a little longer intake runner and flows more cfm..

http://www.iskycams.com/iskycategory_search.php?engine_id=20&page=0&limit=10&pages=2&model_id2=0&sub_category_id=127&attid=9&attid=&attid=25&compid=69&dealer=no&company_id=69&page=0&limit=10&pages=2&model_id2=&sub_category_id=127&brand_id=
good luck

[f_inscreenname]

I just finished my 454 and used, Chevy 396-502 cid, RPM Range 2000-4500, Adv Dur 296 intake/296 exhaust, Dur @.050 218 intake/218 exhaust, Valve Lift 519 intake/519 exhaust, Lobe C/L 110.

From what research I did it was the best cam I could come up with for the .210 domed pistons I installed.
:)

[KerrLake]

I found on an old thread that says my stock q-jet is 830cfm. Does anyone know if this is correct? I would like to use the rpm airgap and keep my stock carb. I love the way the 4" exhaust sounds, but also love how quiet my 3" is. I don't want to do all this in vain because my stock exhaust holds back my performance. Is that what I would be doing?

[mrfixxall]

I found on an old thread that says my stock q-jet is 830cfm. Does anyone know if this is correct? I would like to use the rpm airgap and keep my stock carb. I love the way the 4" exhaust sounds, but also love how quiet my 3" is. I don't want to do all this in vain because my stock exhaust holds back my performance. Is that what I would be doing?

If your spending all this money for a rebuild you may as well spring another 1700.00 forthe exhaust.....you will loose a good 100 lbs
As for your q-jet, the parts for the inside you have to order at your local dealer or buy your self a mini drill kit to open the primary jets up..Once you open them up that it no going backwards..as for the secondarys you either change the meatering rods to fatten it up or i seen other guys take them to the grinder..i prefer changing them.....A holly is much easier to tune and all the parts are avaliable at your local performance shop..
B rake
o out
a nother
t housand

http://www.eddiemarine.com/store/cart.php?m=product_detail&p=13075&c=63

[KerrLake]

Hey guys. Here is what I'm planning on going with. Bore for new stock style pistons. Zero deck the block. Stock heads with larger intake valves. RPM airgap and 800 cfm Holley. Blend the bowls and port job. I like Mr. Fixalls Isky cam profile, so I'm going with it:part # 396271/281-14
lift
I .543
E .565
duration
I 270
E 280
duration at .050
I 221 deg
E 232 deg
lobe center
114 deg.

I haven't decided which exhaust system yet, but a new exhaust as well. How does this sound and am I forgetting anything? What is the best bang for my buck exhaust sytem? Remember, thanks to you guys I'm spending about twice what I had planned to! (just kidding)

Brian

[BUIZILLA]

degree the cam to 109* IC...

[RickR]

If you go with the Isky Cam, 0 deck, Felpro .039 head gasket and a 109 IC your valve/piston clearance should be OK, but I would still check it.

[KerrLake]

This is the recommended setup info from ISKY.
ENGINE INFO: CHEVY BIG BLOCK V8 396-402-427-454 CU.IN. APPLICATION:
SPECIAL REMARKS: HYDRAULIC PRODUCT USE: STREET/STRIP

RPM RANGE: 2200-6500
Valve lift is calculated with zero lash and rocker ratio of 1.75
INTAKE TIMING DURATION: 270 deg.
OPEN: 21 BEFORE TDC
CLOSE: 69 AFTER BDC
CAM LIFT: .310"
VALVE LIFT: .542"
VALVE LASH: . HOT
. COLD
EXHAUST TIMING DURATION: 280 deg.
OPEN: 74 BEFORE BDC
CLOSE: 26 AFTER TDC
CAM LIFT: .323"
VALVE LIFT: .565"
VALVE LASH: . HOT
. COLD


LOBE CENTER: 114 deg. OVERLAP: 47 deg. CAM ADVANCE: 0 deg.
THE ABOVE TIMING IS CHECKED AT .007 (OPEN) LIFTER RISE
.008 (CLOSE)

The following timing is taken at .050" lifter rise and gives a more accurate determination of camshaft position.
INTAKE DURATION: 221 deg.
OPEN: -3.5 BEFORE TDC
CLOSE: 44.5 AFTER BDC
EXHAUST DURATION: 232 deg.
OPEN: 50 BEFORE BDC
CLOSE: 2 AFTER TDC


RECOMMENDED ISKY CAM KIT PARTS AND SETUP INFORMATION
LIFTERS: 202-HY LIFTER TYPE: HYDRAULIC
SPRING: 8005-A TYPE: dual w/damper DIA.: 1.530" RATE: 400 lbs per inch
INSTALLED HEIGHT: 1.875" SEAT PRESSURE: 135 lbs OPEN PRESSURE: 395 lbs
COIL BIND: 1.160"
SPRING SHIMS: # 2
STEEL RETAINERS: 347-ST
TITANIUM RETAINERS: 91-TI
PUSHRODS: 203-96 TYPE: heat treated non-adj LENGTH: int - 8.281" / Exh - 9.250" DIA.: 3/8"
ROCKER ARMS: 204-96 TYPE: roller RATIO: 1.72
VALVE LOCKS: VL-3/8
VALVE LOCKS: VL-3/8

Why 109 instead of 114? I'm just learning what all of the numbers really mean. I ordered the recommended parts also to be sure that everything works well together. Am I going in the right direction?
Brian

[mrfixxall]

Brian, Does your guy have a dyno? Have him brake the cam in with only the outter springs in the heads....after he brakes the cam in have him install the inner valve springs.....This way the valve pressure doesn't wipe out a cam lobe..BTW the that cam started making hp at 1800 rpm and stopped around 5600 rpm...

[BUIZILLA]

lobe split and intake centerline is 2 different things..... lobe split never changes.... by moving the IC number you change the torque band and personality of the engine to a more usable and less peaky torque number, but building the same upper rpm power without turning the engine more rpm to get the job done, this profile will allow 5000-5300 max rpm with a strong 3200-3500 rpm cruise range. I like that cam grind myself, good choice, stable and smooth idle, good vacuum signal for crisp throttle response with the 800 carb. The 47* overlap will have a definate *tone*, but not obnoxious, it should idle at 700 in gear and 800-850 out of gear. I would run it at 1200 rpm in gear, mushing along, and check the vacuum number, if it's over 10.5" I would run a 8.5 PV in the front and 6.5 in the back, and call it good. Watch your piston to valve clearance especially on the exhaust side through it's whole rotation, the cam spec's use a 1.75 rocker, but the real ratio is closer to 1.7, I wouldn't go less than .100 p/v clearance, preferably .110-.130. Back cut the valves for sure...

JH

[KerrLake]

The machine shop cleaned up my old heads and noticed that both were cracked. Could someone offer me some suggestions on specifics. I didn't plan on new heads, only larger intake valves. I'm also going with the exhaust. Where is the best place to get the new heads?

[mrfixxall]

The machine shop cleaned up my old heads and noticed that both were cracked. Could someone offer me some suggestions on specifics. I didn't plan on new heads, only larger intake valves. I'm also going with the exhaust. Where is the best place to get the new heads?


From me! have access at a largge amount of performance cast iron and alunimum heads...Em me your # and ill go over prices with you..

[MOP]

Check the parts for sale section there was a nice set of BB heads there a little while back.

Phil

[KerrLake]

Would I be on the right track with these:

Brand: Edelbrock
Product Line: Edelbrock Marine-Duty Performer RPM 454 Cylinder Heads
Part Type: Cylinder Heads
Cylinder Head Style: Assembled
Cylinder Head Material: Aluminum
Cylinder Head Finish: Natural
Combustion Chamber Volume (cc): 118
CNC Machined Combustion Chamber: No
Intake Runner Volume (cc): 290cc
Exhaust Runner Volume (cc): 118cc
CNC Machined Intake Runner: No
CNC Machined Exhaust Runner: No
Combustion Chamber Style: Open chamber
Intake Port Shape: Oval
Intake Port Location: Standard
Exhaust Port Shape: Round
Exhaust Port Location: Standard
Intake Valves Included: Yes
Intake Valve Diameter (in): 2.250 in.
Exhaust Valves Included: Yes
Exhaust Valve Diameter (in): 1.890 in.
Valve Springs Included: No
Damper Spring Included: No
Retainers Included: No
Locks Included: No
Valve Stem Seals Included: No
Rocker Arm Studs Included: No
Rocker Arms Included: No
Rocker Arm Nuts Included: No
Guideplates Included: No
Accessory Bolt Holes Drilled: Yes
Valve Guides Included: Yes
Valve Guide Material: Manganese bronze
Valve Seats Machined: Yes
Valve Seat Machine Style: 3-angle
Valve Seat Material: Ductile iron
Steam Holes Drilled: No
Oiling Style: Through pushrod
Machined for O-Ring: No
Heat Crossover: No
Quantity: Sold individually.
Notes: Designed for Marine use. The spark plug location has been moved .150 inch closer toward the bore center. Custom pistons are recommended make sure to check clearance before final assembly.



Top-end marine performance.
Designed for 396-502 c.i.d. big block Chevy engines, these Edelbrock cylinder heads include heavy-duty exhaust valves that provide the added durability needed for marine applications, and have one-piece, stainless steel intake valves with hardened tips and swirl-polished heads. The high-velocity flow capabilities of Edelbrock Performer RPM cylinder heads provide increased torque across a wide rpm range that's ideal for marine use. They're cast from A356 aluminum and heat-treated to T6 specs. Their oval-port heads have 110cc chambers and their rectangular port heads have 118cc chambers. Both the oval and rectangular port heads are hard-anodized to protect the aluminum in the harsh marine environments.

???????????

[KerrLake]

By the way Mr. Fix, no easy access to a dyno.

[mrfixxall]

I Dont Like The Fact That You Have To But A Notched Pistom Which Will Drive The Cost Up...try To Find A 320 Cc Intake Runner Cylinder Head,would Be Alot Better In The Upper Rpm Range..