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Under yo mommas bed
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Discussion Starter #1
Okay, so now that I switched completely from outboards to a vdrive I need some engine building tips.

I have a 468 with 990 heads and a single 850 holley and a very mellow cam. What I am thinking of doing is switching to a tunnel with 2 750 4150s , adding nitrous and a nice cam. Problem is I don't know anything about cams and what will work with these heads. I am not going to do any work to the heads at this time or to the lower end . We shall see if it lets loose or not. Can I get an AMEN?? Well, a cam reccomendation will do it.:D I really can't afford to keep buying crap I can't use so someone please help an old man out.
Thax
jangles
 

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I would use something in the .630 lift range with a duration of 260 or so @ .050 with a 110 or 112 center on the lobes.
 

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just a ski boat with bark
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Okay, so now that I switched completely from outboards to a vdrive I need some engine building tips.

I have a 468 with 990 heads and a single 850 holley and a very mellow cam. What I am thinking of doing is switching to a tunnel with 2 750 4150s , adding nitrous and a nice cam. Problem is I don't know anything about cams and what will work with these heads. I am not going to do any work to the heads at this time or to the lower end . We shall see if it lets loose or not. Can I get an AMEN?? Well, a cam reccomendation will do it.:D I really can't afford to keep buying crap I can't use so someone please help an old man out.
Thax
jangles
Well what size is the cam in it now, do you like it?

What rpm do you want to spin, what rpm range are you looking for?

What compression, gear, prop are you running?

How much nitrous do you plan on running and how often will you use the nitrous?

What type of cam, flat, roller, hyd, solid?
 

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Under yo mommas bed
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Discussion Starter #4
Well what size is the cam in it now, do you like it?

What rpm do you want to spin, what rpm range are you looking for?

What compression, gear, prop are you running?

How much nitrous do you plan on running and how often will you use the nitrous?

What type of cam, flat, roller, hyd, solid?
Loren, my answer to all of that is I don't know. Seriously, I haven't had the boat in the water.
 

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Distinguished Member
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Loren, my answer to all of that is I don't know. Seriously, I haven't had the boat in the water.
If that's the case, any cam will do. Just pick the one at the bottom of the list and plug it in!!!


Seriously, you might want to run the boat as is and see where you're at. Once you know where your at, it's easier to figure out where to go to get where you wanna be.
 

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AKA Blownjet 468
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If that's the case, any cam will do. Just pick the one at the bottom of the list and plug it in!!!


Seriously, you might want to run the boat as is and see where you're at. Once you know where your at, it's easier to figure out where to go to get where you wanna be.
X2-on the second comment, that is:D
 

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Under yo mommas bed
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Discussion Starter #7
If that's the case, any cam will do. Just pick the one at the bottom of the list and plug it in!!!


Seriously, you might want to run the boat as is and see where you're at. Once you know where your at, it's easier to figure out where to go to get where you wanna be.
Naw, the thing is bone stock and it's out right now. Time to build a motor and I'll gear to it. Next...........:D
 

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AKA Blownjet 468
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what do you mean "bone stock"? if it has 990's on it, it's what, a "bone
stock" LS-6/LS-7? That's a far cry from say a ''surburban short block":D
 

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Purple headed member
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Okay, so now that I switched completely from outboards to a vdrive I need some engine building tips.

I have a 468 with 990 heads and a single 850 holley and a very mellow cam. What I am thinking of doing is switching to a tunnel with 2 750 4150s , adding nitrous and a nice cam. Problem is I don't know anything about cams and what will work with these heads. I am not going to do any work to the heads at this time or to the lower end . We shall see if it lets loose or not. Can I get an AMEN?? Well, a cam reccomendation will do it.:D I really can't afford to keep buying crap I can't use so someone please help an old man out.
Thax
jangles
If you want a flat tappet dealio run the Isky Z-89. It will work perfect with those heads.....
I would use something in the .630 lift range with a duration of 260 or so @ .050 with a 110 or 112 center on the lobes.
Almost the same specs as the Z-89 (with the exception of the lobe cntr)
what do you mean "bone stock"? if it has 990's on it, it's what, a "bone
stock" LS-6/LS-7? That's a far cry from say a ''surburban short block":D
Those "stock heads" don't give a shit what shortblock is under them and neither will that cam. The bottom end is just along for the ride. The small cam with the lousy design of the 990 head will work perfect from an 8:1 stocker to a 12:1 LS7.
In a decent set up true flatty that combo should run a tic over 90. Faster of course in a Runner bottom. Ask me how I know.....
 

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Under yo mommas bed
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Discussion Starter #10
Thank you , I need all the help I can get. This is going in my Sanger hydro, does that change anything concerning cam, etc?


Happy Turkey Day!!!!!!!!!!!!:)
 

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just a ski boat with bark
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Thank you , I need all the help I can get. This is going in my Sanger hydro, does that change anything concerning cam, etc?


Happy Turkey Day!!!!!!!!!!!!:)
If you can run a cranking compression or tell me if it's domed or flat top pistons I can tell you what cams I've had and liked.

I sort of agree with quickjet but I wouldn't cam my boat the same from 8:1 to 12:1, true you can drop the gear to let it spin but there are some drawbacks.

My favorite low compression (9:1) cam with my 990s was 258/[email protected]" on a 110lsa installed on a 108, lift was .588"/.601", not very wild but easy on parts and would turn 7k.

My current cam is being run with a true 12.5:1 and the 990 heads is 268/[email protected]" on a 110lsa installed on a 109, lift is .643"/.633" this one runs harder but is about my limit for a dual purpose deal trying to pull skiers.
 

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AKA Blownjet 468
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OK, from MY personal experience - I have run THIS CROWER SOLID in 2
different engines- 1 was a 9.5 to 1 motor, the other was a 12to 1,

I had the cam for the 9.5to 1 motor ground on a 110*lsa, while the 12 to1
motor was ground to catolog spec on a 107* lsa- both motors ran extremely well- the 12 to1 engine was in a v drive w/ported 990's, a HOGAN'S T-RAM w/2-750's and I believe 19 gears- the 9.5 to 1 motor
had big valve 049's with the "OVAL PORT VICTOR RAM" (pro-street ram)
with 2-650dp's in an "A" impeller 19' jet:)

spec's are as follows: crower # 01355

v-drive jet
292/300adv. 254/[email protected] .050 595/622lift 107llsa 110lsa

funny how this is "oh so close" to Carnival Rides pick! somthing to ponder
isn't it?:)bulb:D:D
 

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From past experience . . .

FWIW . . . , This is what I would do for my jetboat guys that wanted something to run good and sound good, but did not want to do a lot to the rest of the motor, most often bone stock.

There were some cams that Elgin used to make, but a lot of mfgs were making the exact same grind and marketing them under different private labels and names. May have also been a Melling product.

Conventional Hydraulic Lifters, 230/230 @ .050, .544/.544, ground with a 109 LC. Since these were going into a jetboat motor and would never see 6,000, I would put them in at 9 or 10 degrees advanced (Intake CL end up sitting at 99 or 100).

Did everything they expected, sounded good, and picked up about 15% - 20% in fuel economy from their stock setup and used regular fuel. You will hear lots of guys that won't agree and think this is too much advance, but the results were solid and troublefree (if they used the right oil and kept it free of water).

Worked very well for me and my customers, but, you will most likely crispy critter that deal if you use the nitrous.

Take care, K
 

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If you want a flat tappet dealio run the Isky Z-89. It will work perfect with those heads.....

Those "stock heads" don't give a shit what shortblock is under them and neither will that cam. The bottom end is just along for the ride. The small cam with the lousy design of the 990 head will work perfect from an 8:1 stocker to a 12:1 LS7. In a decent set up true flatty that combo should run a tic over 90. Faster of course in a Runner bottom. Ask me how I know.....

Thats probably a good bet. Im at 11:1 CR, TR with 660's running the Isky Z-97 which is .665 int/.654 exh with a 274/286 duration @ 110 degree lobe ctr. with 990 ported heads. Isky has all the springs, rockers and everything together in kit package.

http://www.iskycams.com/onlinecatalog.html
 

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someofamitch
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to give you an idea on the isky cam(s) we rund the 654 (solid) un-ported 990 heads stock GM dual Plane manifold, 830 Holley prepped by John Avery, APBA legal JE Pistons in a .060 over 427 ci in Super Stock Flat. My motor on a dyno in vegas made 610 hp at 6800-7000 rpm. can't remember what the torque was but it came up quick and held steady. We also ran the RR-650 (which is a roller) in the boat with 500ci Injected on Alky 14:1cr never dyno'd that motor but we did pretty good in Pro-Stock class with it. These are the grind numbers in the catalog.

Hope it helps.

James Gregory
SS/PS 75
 

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Man You Have NO Idea What you Just Started!!!!!!!!:)hand
 

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Man You Have NO Idea What you Just Started!!!!!!!!:)hand
LOL.....NO KIDDING...:D
Jangles....your best bet is to pick out 3 different sets of heads, 5 different cams and probably 7 different intakes with a crate of carburators. Get all that together and head to the nearest Dyno room facility. Assemble your combos and a cool 20 grand later in Dyno charges you will be able tell the class what you learned....:)devil
Looking forward to your report....
 

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Thats probably a good bet. Im at 11:1 CR, TR with 660's running the Isky Z-97 which is .665 int/.654 exh with a 274/286 duration @ 110 degree lobe ctr. with 990 ported heads. Isky has all the springs, rockers and everything together in kit package.

http://www.iskycams.com/onlinecatalog.html
That's a damn good combo right there.....:)devil
 

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I have a Comp roller in my low compression 565, 262 - 268 @ .050, 110 LSA on a 108 ICL, with a lift of .714. With a couple of 600 DP's on an Eddie TR it made a little over 800HP @ 6200, idles in gear at 800 with no back lash in the v-drive, and pulls hard all the way to 7500, could not be happier with the set-up.

And after you get the cam dialed in, pick up one of those fancy TR tops that Carnivalride sells, made my engine even more responsive than last year, I think it also helped my fuel mileage somewhat, and it definately improves the looks by a bunch.
 

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LOL.....NO KIDDING...:D
Jangles....your best bet is to pick out 3 different sets of heads, 5 different cams and probably 7 different intakes with a crate of carburators. Get all that together and head to the nearest Dyno room facility. Assemble your combos and a cool 20 grand later in Dyno charges you will be able tell the class what you learned....:)devil
Looking forward to your report....
Well There ya go. Just saved you having to read 5 Pages of ?????? :)devil
 
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