Performance Boats Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
460 Posts
Discussion Starter #1
Stock short block in good shape. (60psi @ idle when warm)
D0ve heads minor exhaust port work. Heavy duty springs. Modified valve stems to accommodate cam. Screw in 7/16 studs and 3/8 pushrods.
9.5-1 compression
Comp cams CL-34-243-5 278h cam. Flat tappet hyd lifter
Roller 1.7 rockers.

Weiland tunnel RAM with dual holly 450
Imco center rise offshore exhaust 3.5" outlet

Considering this is one of my first BBF builds I would appreciate all input.
It's going to be pushing a 19' Hallett mini cruiser
Thanks
 

·
Registered
Joined
·
931 Posts
Stock short block in good shape. (60psi @ idle when warm)
D0ve heads minor exhaust port work. Heavy duty springs. Modified valve stems to accommodate cam. Screw in 7/16 studs and 3/8 pushrods.
9.5-1 compression
Comp cams CL-34-243-5 278h cam. Flat tappet hyd lifter
Roller 1.7 rockers.

Weiland tunnel RAM with dual holly 450
Imco center rise offshore exhaust 3.5" outlet

Considering this is one of my first BBF builds I would appreciate all input.
It's going to be pushing a 19' Hallett mini cruiser
Thanks
9.5-1 Compression with DOVE-c? Put in SCJ,or CJ sized valves, port match intake and exhaust, and maybe different manifold. Get a bigger cam, maybe COMP CAMS HYDRAULIC CAMSHAFT xm288h 1.,73 Roller rockers, upgraded ignition system, and deck the heads for more compression.
You might want to ask lakesonly, here on the boards, or www.highflowdynamics.com Paul can work wonders with a 460 ford!!:)devil
 

·
Registered
Joined
·
460 Posts
Discussion Starter #3 (Edited)
Thanks mike. I should have mentioned that I'm really trying to get this thing on the water asap and as cheap as possible. I have a trip in 2 weeks that I'm taking an its gotta be ready by then. I'd love to just drop it off with LO and pick it up when its done but I seemed to have misplaced that extra $10k I had laying around :)

I didn't go with the 288 grind because of reversion concerns.
On the compression, those are the numbers with stock pistons according to the machine shop. Were you questioning because you would have expected higher or lower?
I'm really looking for the "oh know don't do that" or if you make this little tweak it pay off big time.
 

·
Registered
Joined
·
273 Posts
Thanks mike. I should have mentioned that I'm really trying to get this thing on the water asap and as cheap as possible. I have a trip in 2 weeks that I'm taking an its gotta be ready by then. I'd love to just drop it off with LO and pick it up when its done but I seemed to have misplaced that extra $10k I had laying around :)

I didn't go with the 288 grind because of reversion concerns.
On the compression, those are the numbers with stock pistons according to the machine shop. Were you questioning because you would have expected higher or lower?
I'm really looking for the "oh know don't do that" or if you make this little tweak it pay off big time.
There are a lot of upgrades you could make, but with time concerns, run it. You didn't say what ignition you have. Upgrading to a MSD set up would be a good investment especially if it has a Prestolite disty. Check out www460ford.com fourm for different builds.
 

·
Registered
Joined
·
3,869 Posts
Run it a bit and check the plugs! those 450 carbs are small and the 460 with a dove head tend to like alot of feul. M
 

·
Registered
Joined
·
536 Posts
if your heads are off,cc them so you know. dished piston or flats? i have flats with c9ve heads & i'm makin bout 10.6:1.pretty sure the c9's & the dove's cc bout the same.i have the same cam as u ,t/r with 600's. seems to run pretty happy
 

·
Registered
Joined
·
335 Posts
Ya need one of these.......




But seriously, the cam recommendation is good! I ran the 292 solid version of the same cam in my last 460 build, a tad more compression (10.5:1) and I agree your carbs are WAY too small! I was running twin 750's and the plugs were perfect every time. Granted, I did not run them sideways (hate that and theres reasons why), and they were 4160's.

I happen to have a pair of 660 center squirters available that I was dying to try, but then this blower motor and testosterone took over and.........well.........you get the picture.

Ray
 

·
Registered
Joined
·
931 Posts
Thanks mike. I should have mentioned that I'm really trying to get this thing on the water asap and as cheap as possible. I have a trip in 2 weeks that I'm taking an its gotta be ready by then. I'd love to just drop it off with LO and pick it up when its done but I seemed to have misplaced that extra $10k I had laying around :)

I didn't go with the 288 grind because of reversion concerns.
On the compression, those are the numbers with stock pistons according to the machine shop. Were you questioning because you would have expected higher or lower?
I'm really looking for the "oh know don't do that" or if you make this little tweak it pay off big time.
Reversion is an issue if you are running headers. Thats what I was told. The wet headers and big cams can suck moisture and water in to the motor through the injectors. If you are running manifolds, you dont really need to worry about it. If you know what cut impeller you have, you can call a few performance jet boat places,a nd they can set you with the right cam grind, and maybe you could benifit from a loader grate. The igntion is a huge up grade, like was said above, 600 cfm carbs a good upgrade.
 

·
Registered
Joined
·
460 Posts
Discussion Starter #10
if your heads are off,cc them so you know. dished piston or flats? i have flats with c9ve heads & i'm makin bout 10.6:1.pretty sure the c9's & the dove's cc bout the same.i have the same cam as u ,t/r with 600's. seems to run pretty happy
Roger good to know that cam is a good one. I spoke to a guy at Comp and told him about the boat and motor, he came back with that reccommendation. I'm running the stock pistons, the machine shop told me my CR. If the girl in your av is riding in your boat does the wind drag slow you down?

Ya need one of these.......




But seriously, the cam recommendation is good! I ran the 292 solid version of the same cam in my last 460 build, a tad more compression (10.5:1) and I agree your carbs are WAY too small! I was running twin 750's and the plugs were perfect every time. Granted, I did not run them sideways (hate that and theres reasons why), and they were 4160's.

I happen to have a pair of 660 center squirters available that I was dying to try, but then this blower motor and testosterone took over and.........well.........you get the picture.

Ray
Ray you're not kidding I for sure need one of those! I just sold a a pair of Holley 750's. That blows. Let me know what ya want for those 600's.

Bill
 

·
www.highflowdynamics.com
Joined
·
1,161 Posts
Stock short block in good shape. (60psi @ idle when warm)
D0ve heads minor exhaust port work. Heavy duty springs. Modified valve stems to accommodate cam. Screw in 7/16 studs and 3/8 pushrods.
9.5-1 compression
Comp cams CL-34-243-5 278h cam. Flat tappet hyd lifter
Roller 1.7 rockers.

Weiland tunnel RAM with dual holly 450
Imco center rise offshore exhaust 3.5" outlet

Considering this is one of my first BBF builds I would appreciate all input.
It's going to be pushing a 19' Hallett mini cruiser
Thanks
Received your email last week, been away for the last few days.

Per your email, I feel that both the XM298 and the XM288 are way too big for your devloping engine combination. I would recommend an XM270, and if you simply must think "big cam" then the XM278 as a maximum, but note that it is not the camshaft that I am personally recommending.

I believe you are the one that mentioned over the phone that your valve springs were hydraulic flat tappet springs with 135 seat pressure. It's also important to know the installed height (for roller rocker arm clearance reasons) which I hope to be 1.900" and not the OEM 1.82". Further, for the camshafts I noted (especially the XM278 with 0.576" valve lift) you need to evaluate retainer-to-guide clearance on the D0VE heads.

The twin 450s will allow the engine to run but I've always felt that 600 cfm vacuum secondaries should be the minimum consideration. The 600 cfm vacuum carbs will still provide good fuel econmy...as far as dual-carbed tunnel rams go. (Less true with Holley 660's.)

Remember what I said about checking exhaust port alignment with the thru-transom exhaust logs.

In summary, my vote is for the XM270 and a pair of Holley 600's.

LO
 

·
steelcomp was here
Joined
·
26,515 Posts
Reversion is an issue if you are running headers. Thats what I was told. The wet headers and big cams can suck moisture and water in to the motor through the injectors. If you are running manifolds, you dont really need to worry about it. If you know what cut impeller you have, you can call a few performance jet boat places,a nd they can set you with the right cam grind, and maybe you could benifit from a loader grate. The igntion is a huge up grade, like was said above, 600 cfm carbs a good upgrade.
Any time you have water introduced into the exhaust system you have to be concerned with reversion. The IMCO Powerflows are no exception. With typical tube/OT headers, most setups have the option of being able to shut down the water at or near idle which is where most of the reversion issues occur. Manifolds such as the Powerflows or other jacketed manifolds don't have this option and are way more sensitive to reversion issues since there is always water in the exhaust, even at idle. With most tube/OT header systems, the majority of the water coming out of the engine is dumped overboard and very little is typically going through the exhaust. With jacketed wet exhaust systems, all the engine water can be exiting through the exhaust which greatly increases the possibility of reversion. Jacketed manifolds also have a bit more back pressure than a typical tube header which increases the possibility of reversion. Where the water is introduced into the exhaust system is also a factor, and the further away from the ex. port the better for helping to prevent reversion.
 

·
Registered
Joined
·
460 Posts
Discussion Starter #13
It's also important to know the installed height (for roller rocker arm clearance reasons) which I hope to be 1.900" and not the OEM 1.82". I'm not sure I follow what you mean here. Installed height of what?


Further, for the camshafts I noted (especially the XM278 with 0.576" valve lift) you need to evaluate retainer-to-guide clearance on the D0VE heads. I took the cam card and the heads back to the machine shop and they cut down the guides to solve this issue.

I'm on the hunt for a pair of carbs.

Paul thank you for the advice and the time it takes to follow up on these posts. I was on the 460 forum over the weekend and I see that you spend a great deal of time on that forum too. You teach a lot of people about these old hunks of iron and spend many hours of unpaid personal time to do so. The information you spread is so valuable to so many of us. Thank you again. I look forward to having you spend some paid time on this motor later in the year after my immediate needs for the summer are met.

Bill Louder
 

·
Registered
Joined
·
931 Posts
Any time you have water introduced into the exhaust system you have to be concerned with reversion. The IMCO Powerflows are no exception. With typical tube/OT headers, most setups have the option of being able to shut down the water at or near idle which is where most of the reversion issues occur. Manifolds such as the Powerflows or other jacketed manifolds don't have this option and are way more sensitive to reversion issues since there is always water in the exhaust, even at idle. With most tube/OT header systems, the majority of the water coming out of the engine is dumped overboard and very little is typically going through the exhaust. With jacketed wet exhaust systems, all the engine water can be exiting through the exhaust which greatly increases the possibility of reversion. Jacketed manifolds also have a bit more back pressure than a typical tube header which increases the possibility of reversion. Where the water is introduced into the exhaust system is also a factor, and the further away from the ex. port the better for helping to prevent reversion.
Cool! Good to know, wspecially since I have a 460!
 

·
Registered
Joined
·
931 Posts
It's also important to know the installed height (for roller rocker arm clearance reasons) which I hope to be 1.900" and not the OEM 1.82". I'm not sure I follow what you mean here. Installed height of what?


Further, for the camshafts I noted (especially the XM278 with 0.576" valve lift) you need to evaluate retainer-to-guide clearance on the D0VE heads. I took the cam card and the heads back to the machine shop and they cut down the guides to solve this issue.

I'm on the hunt for a pair of carbs.

Paul thank you for the advice and the time it takes to follow up on these posts. I was on the 460 forum over the weekend and I see that you spend a great deal of time on that forum too. You teach a lot of people about these old hunks of iron and spend many hours of unpaid personal time to do so. The information you spread is so valuable to so many of us. Thank you again. I look forward to having you spend some paid time on this motor later in the year after my immediate needs for the summer are met.

Bill Louder
Everytime I read something about 385 series fords, i learn something new. Usually its from LO and very valuable info! I just saved this thread so I can read it when its time for me to cam up with my DOVE-c heads. Sorry if I was off base on the cam bit.:)hand
 

·
Registered
Joined
·
3,869 Posts
received your email last week, been away for the last few days.

Per your email, i feel that both the xm298 and the xm288 are way too big for your devloping engine combination. I would recommend an xm270, and if you simply must think "big cam" then the xm278 as a maximum, but note that it is not the camshaft that i am personally recommending.

I believe you are the one that mentioned over the phone that your valve springs were hydraulic flat tappet springs with 135 seat pressure. It's also important to know the installed height (for roller rocker arm clearance reasons) which i hope to be 1.900" and not the oem 1.82". Further, for the camshafts i noted (especially the xm278 with 0.576" valve lift) you need to evaluate retainer-to-guide clearance on the d0ve heads.

The twin 450s will allow the engine to run but i've always felt that 600 cfm vacuum secondaries should be the minimum consideration. The 600 cfm vacuum carbs will still provide good fuel econmy...as far as dual-carbed tunnel rams go. (less true with holley 660's.)

remember what i said about checking exhaust port alignment with the thru-transom exhaust logs.

In summary, my vote is for the xm270 and a pair of holley 600's.

Lo
x2 000000000000000
 

·
Registered
Joined
·
460 Posts
Discussion Starter #17
I did go with the 278 cam. I had the guides machined. I'm on the path of tracking down new carbs. Further more I decided to have the short block gone through. The thought of putting all these new parts in and not having it checked out just wasn't making since. I should have it back Tuesday. Anybody need a pair of brand new 450's?
 

·
www.highflowdynamics.com
Joined
·
1,161 Posts
I did go with the 278 cam.
In your combination, the 278 should make a little more power than the 270. But in order for the 278 to really shine the intake ports on your iron heads ought to be ported as well, with a 2.19" or 2.25" intake valve and associated bowl work. That's why I said, "if you simply must think 'big cam' then the XM278 as a maximum, but note that it is not the camshaft that I am personally recommending."

It will work :) , and somewhat better than the 270; and, the 278 will work much better if the heads were fully ported. Simply put, "adding more camshaft in an effort to make up for the shortcomings of an unported head, a 278 cannot do."

LO

"
 
1 - 18 of 18 Posts
Top