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BBC cam question up grade XR288HR

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Old 09-11-2017, 01:50 PM
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Default BBC cam question up grade XR288HR

I built my engines from a 454 Mag 365 HP set up. I used the Lunati Vodoo cam #10110704 flat hyd cam with 233/241 @.050 with a 110 lobe center. This equals out to a 17 deg overlap. I want to up-grade to roller cams and I am looking at the Comp Cams 11-433-8 XR288HR with 236/242 @ .050 with a lobe center of 110 which comes out to 19 deg of overlap. I am running a modified Gil dry exhaust (the pipes were cut and the water mixes right before the transom at the exhaust tip). I had zero reversion problems with the Lunati cams, would the comp cams cause any issues with 2 more degrees of overlap???
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Old 09-11-2017, 09:12 PM
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i,m no cam expert but i would be afraid to use any cam with a 110 lsa and gill exhaust unless it was totally dry.
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Old 09-12-2017, 07:51 AM
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Quote:
Originally Posted by mike tkach View Post
i,m no cam expert but i would be afraid to use any cam with a 110 lsa and gill exhaust unless it was totally dry.
lol, I like the preface, who are the cam experts?....Guys like you that have proven Dyno HP.
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Old 09-12-2017, 11:04 AM
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I'm no expert at anything, but I've read too many instances of reversion with even a wider lsa. My current cam has 110lsa with headers that dump at the tips and no evidence of reversion, but I'm switching it out this winter to comp cams version of the 525EFI cam just to be safe. As a side note, the 110lsa gives a nice raspy idle that sounds like a quarter mile gasser that sounds impressive at the dock but can get tiresome in long idle situations. I like open pipes but the gf has envy of the quiet ski boats that roll up to the docks. It may be easier to just get a new gf in my case though.
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Old 09-12-2017, 11:13 AM
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Id try to find a 525 cam, being ground on a 114 split vs the 741 at a 112....if memory serves me....jmo
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Old 09-13-2017, 09:39 AM
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Tons of guys have ran the 741 crane with wet exhaust. I ran it with short stainless marine risers, no reversion. The 741 has 16 degrees of overlap. Lots of variables when it comes to whether or not it will revert. A simple adjustment of base timing can make a difference.

If you know a good tig welder, extending the pipes thru the transom is not a big deal.
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Old 09-13-2017, 02:19 PM
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How about a Lunati 20010671. Duration moves up and a bit more lift. Still 114 lsa.
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Old 09-13-2017, 02:40 PM
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i have a 525 efi takeout cam that i might sell,the only difference from it and a crane 168741 is the lsa,114 on the efi cam and 112 on the 168741.i have used quite a few 741 cams and did exactly what mild thunder said,extend the pipe through the transom.
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Old 09-13-2017, 02:46 PM
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their is a reason mercury marine uses a crane billit core camshaft and it is not because they like to spend more than they need to.i won,t install a cast core hyd roller camshaft in any high performance marine engine,same as mercury marine.
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Old 09-13-2017, 03:06 PM
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^^^ Is the Lunati a cast core?
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