Crane 731 or 741
09-25-2007, 01:19 PM
#12
VIP Member
[QUOTE=Griff;2283971]The 731 is almost the same as the stock cam.
I would use a 525EFI cam. Its the same as a 741 except it has a 114 lobe sep.[/QUOTE
Thats prob what I would go with also or get Bob to cut ya one, I run the 741 it has a pretty good bit of overlap. The 114 will help in this area,Ck with JC Perf he might have some take outs.
My heads are ported and with the 741 I see signs of carbon in the intake from the overlap and low port velocity,But thats given me some cushion with blow thru at the boost Im running.
If I had to do it over again I would get Bob to cut me a cam for my application
I would use a 525EFI cam. Its the same as a 741 except it has a 114 lobe sep.[/QUOTE
Thats prob what I would go with also or get Bob to cut ya one, I run the 741 it has a pretty good bit of overlap. The 114 will help in this area,Ck with JC Perf he might have some take outs.
My heads are ported and with the 741 I see signs of carbon in the intake from the overlap and low port velocity,But thats given me some cushion with blow thru at the boost Im running.
If I had to do it over again I would get Bob to cut me a cam for my application
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09-25-2007, 04:59 PM
#13
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Rob, I hear ya. That's why I started the thread. I thought the 741 may be a bit much for the bone stock 500's but wanted to hear some "real world" results from people.
BTW, know Kip well. He ground the cams for my Formula. Does some great work. I may talk to Bob and see if he thinks a custom grind may do me a little better. If the concensus is the 525 sticks, I'll call JC.
Shoulda just stole a set of 700's while we were touring the Cig plant in April. Hell, there had to have been 8 or 10 of them sitting there. They would have never missed 2!
Last edited by Croozin2; 09-25-2007 at 05:03 PM.
09-25-2007, 11:16 PM
#14
Hey Tom! Yeah, I know what I SHOULD do, but really didn't want to drop a bunch of money into working the heads etc. Like I said, already got 1 damaged cam, while I was replacing (and freshening the motors), I figured may as well move up the food chain a little!
Rob, I hear ya. That's why I started the thread. I thought the 741 may be a bit much for the bone stock 500's but wanted to hear some "real world" results from people.
BTW, know Kip well. He ground the cams for my Formula. Does some great work. I may talk to Bob and see if he thinks a custom grind may do me a little better. If the concensus is the 525 sticks, I'll call JC.
Shoulda just stole a set of 700's while we were touring the Cig plant in April. Hell, there had to have been 8 or 10 of them sitting there. They would have never missed 2!
Rob, I hear ya. That's why I started the thread. I thought the 741 may be a bit much for the bone stock 500's but wanted to hear some "real world" results from people.
BTW, know Kip well. He ground the cams for my Formula. Does some great work. I may talk to Bob and see if he thinks a custom grind may do me a little better. If the concensus is the 525 sticks, I'll call JC.
Shoulda just stole a set of 700's while we were touring the Cig plant in April. Hell, there had to have been 8 or 10 of them sitting there. They would have never missed 2!
__________________
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The Only Time You Have To Much Ammo Is When Your Swimming Or On Fire.
.
The Only Time You Have To Much Ammo Is When Your Swimming Or On Fire.
09-26-2007, 07:51 AM
#16
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09-26-2007, 09:01 AM
#17
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They're supposed to be the stock Merc/Crane units. I PM'd Bob last night and plan tio give him a call today to discuss a little further. He seems to think the lifter issue was not actually a failure of the lifter itself but something else that failed and ultimately affected the lifter. As far as what I'm going back with, that will depend on the information I obtain during this process. If there's a better mousetrap I'm always interested.
The stock 500HP's came with Crane lifters. I went with Morels from Bob, no problems so far. Also, the Crane lifters floated the valves at ~5600 rpm on the dyno. Morels held to 6000 rpm with no float. Maybe not a factor for you if you run stock ignition with 5300 rpm rev limiter but interesting anyway.
09-26-2007, 09:15 AM
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I did a cam swap on a couple of HP500s last year. We used the 731 cams and did a bowl blend on the heads. They dyno'd at 510 at the prop at 5600 RPM. I believe the 741 would push the power peak up to around 6000 RPM on this engine. The 525 efi cam would peak a little lower. Also keep in mind the efi on the 525 will produce better low end torque than the Dart single plane intake on the 500. You need to establish where you want the RPM to peak before chosing a cam. I personally think the 741 would put the RPM peak out of the usable range.
09-27-2007, 07:31 AM
#19
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Here's some good reference info....,
I remember about 6 years ago someone who used a 741 cam in his 509cid engine with Iron Eagle 308 heads with some clean-up work NO porting, 950 Holley, 8.8-9.0 comp ratio, Edlebrook Air-Gap intake manifold, and with dyno tubular headers he made 563hp @5750rpm on Tyler Crocket's dyno.
The engine was installed with Lightning headers in a 27' Warlock w/stepped hull. He seemed to like the way it perfrormed.
I remember about 6 years ago someone who used a 741 cam in his 509cid engine with Iron Eagle 308 heads with some clean-up work NO porting, 950 Holley, 8.8-9.0 comp ratio, Edlebrook Air-Gap intake manifold, and with dyno tubular headers he made 563hp @5750rpm on Tyler Crocket's dyno.
The engine was installed with Lightning headers in a 27' Warlock w/stepped hull. He seemed to like the way it perfrormed.
Last edited by KAAMA; 09-27-2007 at 07:35 AM.
