SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: mayhem35 on August 05, 2014, 01:08:13 PM
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Hey guys, need opinion and/or views on a cam kit....I have a 396 bbc 30 over I think, gm hi perf heads roller tip rockers....flattened my cam, 2 collapsed lifters and a broken spring. I was looking at comp cam kits and got three that I think would work but not sure... :banghead: info greatly appreciated...here are my 3 choices
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A few of us have ran the xm 278 and love it. I have it in my 454 now. The torque curve is amazing.
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Any concerns with water reversion?
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What heads do you have?
My stock 049 large oval port heads only had clearance for about .575 lift. Any more than that and you will have to have the spring inner bosses machined for added clearance (it'll start crushing the valve stem seals).
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http://youtu.be/JU_WFp6fx0w
Her is a pic of my cam card and a video of what it sounds like. I bought the matching springs with the cam. I also have 049 heads. I am very pleased with the performance of my boat. The torque through the powerband is outstanding. Sounds bitchin' too.
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From my understanding they specifically designed all of their marine cams to prevent reversion
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I run my headers dry though. Running them wet just isnt worth the risk to me. I've seen and heard of too many people blowing there engine because a check valve gets stuck
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This is going to sound condescending... And maybe it is.
So you lost a cam due to going flat..... And your going to put in another flat tappet?
I instantly heard my grandads voice "when something breaks, that is the perfect time to make it much better".
Turn in some beer bottles for a while and get a roller camshaft. Do it once, do it right.
GT
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What heads do you have?
My stock 049 large oval port heads only had clearance for about .575 lift. Any more than that and you will have to have the spring inner bosses machined for added clearance (it'll start crushing the valve stem seals).
Not sure what exactly kind of heads they are..... :banghead: I know they are rectangle port gm hi perm.....here's a few pics if it can help.
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This is going to sound condescending... And maybe it is.
So you lost a cam due to going flat..... And your going to put in another flat tappet?
I instantly heard my grandads voice "when something breaks, that is the perfect time to make it much better".
Turn in some beer bottles for a while and get a roller camshaft. Do it once, do it right.
GT
i was going to do an xm comp cam hydraulic flat tappet....few guys have said go full roller...checked out the price and as nice as it would be to do and as much beer I would enjoy drinking to afford that I don't think full roller is an option.... :thumbdown:
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Here's the cam I pulled out of boat
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i was going to do an xm comp cam hydraulic flat tappet....few guys have said go full roller...checked out the price and as nice as it would be to do and as much beer I would enjoy drinking to afford that I don't think full roller is an option.... :thumbdown:
Well, then let me know before you buy one and I will sell you mine at a discounted rate... I have the whole kit, brand new in the box. I am ordering a roller and want to put another motor together to potentially run CJ next year.
I can't remember the exact grind, but it is the XM series from comp.
I assume you already built the rest of the motor? That metal went somewhere...
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Looks fairly reasonable to me...
http://www.compperformancegroupstores.com/store/merchant.mvc?Screen=PROD&Store_Code=CC&Product_Code=CL11-445-8&Category_Code= (http://www.compperformancegroupstores.com/store/merchant.mvc?Screen=PROD&Store_Code=CC&Product_Code=CL11-445-8&Category_Code=)
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BTW I have a NIB XM-270-H and Comps lifters.
GT
edit;
If you insist on running a flat tappet deal, install a rev kit. Cheap insurance.
GT
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Well, then let me know before you buy one and I will sell you mine at a discounted rate... I have the whole kit, brand new in the box. I am ordering a roller and want to put another motor together to potentially run CJ next year.
I can't remember the exact grind, but it is the XM series from comp.
I assume you already built the rest of the motor? That metal went somewhere...
didnt find any damage or metal anywhere.... :screwy: just the collapsed lifter....all the sleeves are good oil looked good..a little watery but that was from reversion...
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didnt find any damage or metal anywhere.... :screwy: just the collapsed lifter....all the sleeves are good oil looked good..a little watery but that was from reversion...
Your first post says "flattened my cam".... :screwy:
You screwing with me? You cannot knock a lobe off of a cam without passing quite a lot of metal throughout the engine. Simply cannot be done.
Not trying to stir the pot. Just hate seeing folks throw good money at bad.
GT
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Looks fairly reasonable to me...
http://www.compperformancegroupstores.com/store/merchant.mvc?Screen=PROD&Store_Code=CC&Product_Code=CL11-445-8&Category_Code= (http://www.compperformancegroupstores.com/store/merchant.mvc?Screen=PROD&Store_Code=CC&Product_Code=CL11-445-8&Category_Code=)
this is what I would need....I think...
Xtreme Marine™, XM284HR: Cam & Kit
Product Representation: Actual part may vary based on configuration ordered.
Part: K11-451-8
Price: $1,020.79
Weight: 31.65 lbs FREE SHIPPING OVER $50!
Quantity:
HYDRAULIC ROLLER: Good for jet boat with A impeller. Great for spleasure or performance use.
Click here for Camshaft Specs
*BBC - 1965-66 396 c.i. models have an oiling groove in the rear journal. The listed part numbered cams will not fit these models, so if you require a camshaft with the oiling groove, please call us at 1-800-999-0853 or click here to contact us, and we will assist you with placing an order.
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Your first post says "flattened my cam".... :screwy:
You screwing with me? You cannot knock a lobe off of a cam without passing quite a lot of metal throughout the engine. Simply cannot be done.
Not trying to stir the pot. Just hate seeing folks throw good money at bad.
GT
not screwing with you at all......I'll see if I can send a pic of cam
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Here it is....
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This is what I was leaning towards....
Xtreme Marine™, XM278H: Cam & Kit
K11-240-4
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this is what I would need....I think...
Xtreme Marine™, XM284HR: Cam & Kit
Product Representation: Actual part may vary based on configuration ordered.
Part: K11-451-8
Price: $1,020.79
Weight: 31.65 lbs FREE SHIPPING OVER $50!
Quantity:
HYDRAULIC ROLLER: Good for jet boat with A impeller. Great for spleasure or performance use.
Click here for Camshaft Specs
*BBC - 1965-66 396 c.i. models have an oiling groove in the rear journal. The listed part numbered cams will not fit these models, so if you require a camshaft with the oiling groove, please call us at 1-800-999-0853 or click here to contact us, and we will assist you with placing an order.
Do you have logs?
That is a lot of cam for a cruiser...
GT
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This is what I was leaning towards....
Xtreme Marine™, XM278H: Cam & Kit
K11-240-4
Do you know how nasty that cam is?
GT
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Here it is....
Motor full of fine metal shavings.... Pull it down and measure everything... JMHO.. Also check the front thrust surface of the block behind where the cam sprocket rides.
GT
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Do you have logs?
That is a lot of cam for a cruiser...
GT
no, I have Bassett headers....
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Do you know how nasty that cam is?
GT
no....is this not a good choice....
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Motor full of fine metal shavings.... Pull it down and measure everything... JMHO.. Also check the front thrust surface of the block behind where the cam sprocket rides.
GT
my motor skills aren't that refined :( ...not sure how to pull it down and measure or check the front thrust surface.....
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How much work has been done to your engine?
That XM 278 H is the cam we ran in the marathon motor... Very nasty, requires some work to get it right. It ran good in the race boat, pulled 5,200-5300 with a cleaned up stainless AA impeller with a 10.75:1 468 big block.
Not saying it wont run, quite the contrary, but she will be pretty snotty.
You will have to have the heads worked on, likely have the valve guides cut down for the seals to fit.
I guess it all depends on how the rest of the engine is set up...
Still think the motor has to come completely apart. Which is why I recommended a roller cam. It wont happen again.
GT
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Not sure what has been done....this is the first time I've taken it this far apart....it's a 396 bored .30 over (I think) ,don't know the clearances, "A" impeller. From some research I'm guessing the compression is 10.25-1....
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http://youtu.be/JU_WFp6fx0w (http://youtu.be/JU_WFp6fx0w)
Her is a pic of my cam card and a video of what it sounds like. I bought the matching springs with the cam. I also have 049 heads. I am very pleased with the performance of my boat. The torque through the powerband is outstanding. Sounds bitchin' too.
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I was looking at this one but was wondering if I could step up a little bit to the xm278h.....
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Not sure what has been done....this is the first time I've taken it this far apart....it's a 396 bored .30 over (I think) ,don't know the clearances, "A" impeller. From some research I'm guessing the compression is 10.25-1....
Is the motor still in the boat?
It is my feeling that she needs to be put on the floor and inspected for excessive wear.
At least pull the pan and pass a magnet through it... bet you get that shocked face...
[attachimg=1]
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Yep....and I've already had the shocked FML face many times thru this little adventure and I've somewhat enjoyed it in a twisted jet boat owner way!!!😨😨😨
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Well, then let me know before you buy one and I will sell you mine at a discounted rate... I have the whole kit, brand new in the box. I am ordering a roller and want to put another motor together to potentially run CJ next year.
I can't remember the exact grind, but it is the XM series from comp.
I assume you already built the rest of the motor? That metal went somewhere...
Glenn-
Goin racin'?
I wanna know
Dan'l
Boat is still down side up, shoe is gittin' fitted
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Glenn-
Goin racin'?
I wanna know
Dan'l
Boat is still down side up, shoe is gittin' fitted
Man, I do this to myself every year.
I have nearly everything I need to put a boat together except the time necessary.
I am staring at a potential job change in February that will likely free up some of my time and allow a much more flexible schedule.
I figure on putting together a boat and a motor this winter and see what happens.
There will be a thread if I start...
It is so much fun, if you get the opportunity, get involved.
GT
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Do you know how nasty that cam is?
GT
It will be even more so in a smaller engine.
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my motor skills aren't that refined :( ...not sure how to pull it down and measure or check the front thrust surface.....
what he means is, the motor will have to removed from boat, if installed, and taken apart and inspected. by inspecting, i mean measuring the bearing surfaces on crank and rod (bearing journals)...basically any part that requires oil and rotates has potentially been exposed to fine metal shavings/dust/powder if you will. which acts like an abrasive and can grind down surfaces so that they are out of tolerance...usually resulting in poor oil, low oil pressure...excessive wear, etc. also, it would be wise to have the block's oil passages cleaned...after all, contaminated oil has passed thru them...you wouldnt want any remnants to find its way into the fresh oil of your new build.... dont forget to check/clean oil pump. good luck, keep us posted.