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Discussion Starter #1 (Edited)
Hello,

I am a car guy and I dont know anything about boats but I have a question I hope you guys can help me out with.

I picked up a 502ci Big Block 4 bolt main with rectangle port heads casting # 14097088. The guy who built this engine builds racing engines for both drag boats and offshore racing.

I dont have all the numbers from this engine just yet but what I know so far, it is a full roller engine, Eagle H beam connecting rods, JE pistons, Crane roller lifters, Crane duel valve springs, Aluminum 1.7 rockers, double roller timing chain, Merlin High rise intake, Holly 850 DP carb, Milodon 10 qt oil pan.

My question,
When I remove the rear cover for the cam I see a grind number HR 296-2S-12 IG and what looks like "CR" below that.

When I look this number up I see it is for an engine size of 305-350 ci.... HR- 296- 2S- 12 IG camshaft - Ch. 305 (5.0L)- 350 (5.7L) V8 87- 99

Why would my 502 Big Block have this cam in it???? Isn't this a tiny cam for a 502 BB?

What kind of performance can I expect from this setup?

Thank's for any help here.
 

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I would just say you have carryover grind numbers from one to another,definitely not the same cam,
HR=hydraulic roller, 12 is probaly LSA
 

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Discussion Starter #3
Ok,

Is there another way to find out more info about this cam if were thinking it is just a carry over number?

Thanks again.
 

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steelcomp was here
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It's the big block version of that cam. P/N 139641
Hyd roller
3000-6500rpm
296/304 adv. duration
234/242 @ .05
.610/.632 lift
112 LSA
10.0 - 11.5 compression
They recommend 120# seat pressure and 410# open with their lifters. I don't think you'll ever see 6500 with those springs and lifters.
For marine use I'd run a Morel lifter and run at least 160-170 on the seat, and 475-480 open.
 

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Discussion Starter #5
Thanks stealcomp,

That makes more sense. Is this cam any good? Is is considered small or big? Should I junk it?

This engine is going in a car, is that going to matter?
 

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Thanks stealcomp,

That makes more sense. Is this cam any good? Is is considered small or big? Should I junk it?

This engine is going in a car, is that going to matter?
It is not small and not big. It should be a ok cam for a daily driver. I would think it should make a easy 650 hp maybe 700 depending on the combo. Should have a streetable idle and power brakes should still work. If the car is a automatic I would use a 3000-3500 stall conveter. Am I right Steel?
 

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steelcomp was here
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Thanks stealcomp,

That makes more sense. Is this cam any good? Is is considered small or big? Should I junk it?

This engine is going in a car, is that going to matter?
Good "little" cam for sure. ;) It's fairly large for the street, but not too bad.
It'll have a rough idle, good mid and upper power. They recommend a 3000rpm converter.
 

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steelcomp was here
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It is not small and not big. It should be a ok cam for a daily driver. I would think it should make a easy 650 hp maybe 700 depending on the combo. Should have a streetable idle and power brakes should still work. If the car is a automatic I would use a 3000-3500 stall conveter. Am I right Steel?
Are you? :D You treed me on that one. I guess about 630-640 @ 5800-5900 with those heads.
 

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Are you? :D You treed me on that one. I guess about 630-640 @ 5800-5900 with those heads.
I almost did not put 700 hp but thought with good head work, good intake and a good exhaust it might go that high, You are the expert. Right? That is why I would ask you or Straub before I pulled the trigger on buying one. :D
 

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steelcomp was here
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I was told this engine does have work done to both the heads and exhaust ports...
That's good because in their stock trim, I'd like to see more ex duration. Engine should run real good if it's put together right.:thumb:
 

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Update:

I just found out my engine is a 540 ci. It has a 4.5 Bore and a 4.25 stroke with Eagle crank.
What's the compression ?

If 9:1 I'd say 630-650hp with the components listed above. I can't guess on someone else's headwork.
If 10:1 I'd say 650hp or so.

A 9:1 502 with same components listed above but with AFR 305 or comparable heads would dyno at 610-620hp at 5700/5800 rpm.
A 9:1 540 (everything same as 502 just above) will typically see 650hp.

That cam has been used in kazillions of 502/540 builds for offshore marine engines. Thus knowing the power made by them.
 

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Discussion Starter #17 (Edited)
Digging up an old thread here but I came across it again after all this time and wanted to let you hear the 540 we discussed early in this thread.

The engine now has an aluminum Holley Ultra HP 850 cfi carb and "Doug's" full length ceramic coated headers (2 1/8" tubes w3.5" collector into a Pypes 3.5" X-pipe exhaust)

The little bit of revving here is only on the primary side of the cab. I did not open the throttle enough to get into the secondaries.


https://www.youtube.com/watch?v=IMuCkKzfARo
 
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