Reply With QuoteDo a leakdown test on the cylinders as well. It will give you more details on if and where you are having problems, i.e. valve leak, head gasket leak, pressure past rings etc...
First the specs
78 Hardin Marine 460 ser#HM7-6047
Dooe Intake
D3VE heads
750 Edelbrock
Hardin Marine Exhaust logs and snails
turns 4400 RPM at 58 mph on GPS
Pulled compression check and found the following
Cyl 5--------------------------------Cyl 1
125 dry at 5 revolutions--------------125 psi
------------------------------------- Ex pushrod not rotating
Cyl 6-------------------------------- Cyl 2
125 psi-------------------------------125 psi
Cyl 7---------------------------------Cyl 3
125 psi-------------------------------125 psi
Intake pushrod bent
Cyl 8---------------------------------Cyl 4
120 psi------------------------------ 120 psi
In pushrod not rotating--------------- Ex not rotating
I have no idea whats been done inside but I do know it has not been run much in the last 3 years.
No water or gunk in oil.
Insides look clean so far.
I would like to do a quick fix for this summer with an eye on total rebuild come winter.
My question is, does anyone have any used parts they would like to sell.
I would like used cam, lifters and pushrods first
And what is a good proven combo in the 400 HP range so I can start the gathering process.
Thanks, Alan
Do a leakdown test on the cylinders as well. It will give you more details on if and where you are having problems, i.e. valve leak, head gasket leak, pressure past rings etc...
First the specs
78 Hardin Marine 460 ser#HM7-6047
Dooe Intake
D3VE heads
750 Edelbrock
Hardin Marine Exhaust logs and snails
turns 4400 RPM at 58 mph on GPS
Pulled compression check and found the following
Cyl 5--------------------------------Cyl 1
125 dry at 5 revolutions--------------125 psi
------------------------------------- Ex pushrod not rotating
Cyl 6-------------------------------- Cyl 2
125 psi-------------------------------125 psi
Cyl 7---------------------------------Cyl 3
125 psi-------------------------------125 psi
Intake pushrod bent
Cyl 8---------------------------------Cyl 4
120 psi------------------------------ 120 psi
In pushrod not rotating--------------- Ex not rotating
I have no idea whats been done inside but I do know it has not been run much in the last 3 years.
No water or gunk in oil.
Insides look clean so far.
I would like to do a quick fix for this summer with an eye on total rebuild come winter.
My question is, does anyone have any used parts they would like to sell.
I would like used cam, lifters and pushrods first
And what is a good proven combo in the 400 HP range so I can start the gathering process.
Thanks, Alan
From having to learn ford helping a buddy build a 460 omega to keep up with my 454 Taylor, I'll try to give some help.
The leakdown would be good, are the other 4 cyl similar to those? Looks fair for an older engine. I'd enjoy it this year with a plan like this in mind.
IMO, the worst thing about the fords is the heads, especially the later-model ones. theres a lump in the exhaust port that blocks a lot of it off. On some heads it is frigging HUGE. I wouldn't plan a rebuild without finding a competent racing shop to at minimum grind those ports clear. Then I'd build it to about 10:1 if not already (I bet not), a good dual-plane manifold (my preference) like my Performer RPM Air Gap, keep the carb, it's a good size.
I'm happy with a Hydraulic cam running 280* seat/seat duration, .565" lift but it is a custom grind I got from DuaneHTP. With headers (thru-transom) I should be very close to 400HP on an 8.5-1 otherwise stock 454 (no head work). With a head porting next year, it should carry me very close to 500HP.
I have been told, same situation, the fords do need a heavier cam.
Since they cost so little for the value, I'd replace the rod bolts with ARP's and get the rods resized. Mine cost $70 + an $80 machinist. They may be the strongest part of my 2-bolt lower end. :crossx: A good solid double-roller timing chain setup, I found all-billet gears for mine right at $100.
There is where I'd go. now, if you want more HP, lean on the cam more, but the heads will choke ya untill they get worked or replaced.
From having to learn ford helping a buddy build a 460 omega to keep up with my 454 Taylor, I'll try to give some help.
The leakdown would be good, are the other 4 cyl similar to those? Looks fair for an older engine. I'd enjoy it this year with a plan like this in mind.
IMO, the worst thing about the fords is the heads, especially the later-model ones. theres a lump in the exhaust port that blocks a lot of it off. On some heads it is frigging HUGE. I wouldn't plan a rebuild without finding a competent racing shop to at minimum grind those ports clear. Then I'd build it to about 10:1 if not already (I bet not), a good dual-plane manifold (my preference) like my Performer RPM Air Gap, keep the carb, it's a good size.
I'm happy with a Hydraulic cam running 280* seat/seat duration, .565" lift but it is a custom grind I got from DuaneHTP. With headers (thru-transom) I should be very close to 400HP on an 8.5-1 otherwise stock 454 (no head work). With a head porting next year, it should carry me very close to 500HP.
I have been told, same situation, the fords do need a heavier cam.
Since they cost so little for the value, I'd replace the rod bolts with ARP's and get the rods resized. Mine cost $70 + an $80 machinist. They may be the strongest part of my 2-bolt lower end. :crossx: A good solid double-roller timing chain setup, I found all-billet gears for mine right at $100.
There is where I'd go. now, if you want more HP, lean on the cam more, but the heads will choke ya untill they get worked or replaced.
Thanks Smokin, thats what I am looking for. After thinking on it I will put in a Summit cam and lifters, timing set and new pushrods for the summer with the idea to reuse the pushrods. I have seen some heads for sale on here, but after buying the boat I am going to have to wait a couple months for those.
I am not building a hot rod, just a nice reliable lake boat.
Thanks again, Alan
I am not building a hot rod, just a nice reliable lake boat.
Thanks again, Alan
You say this now but wait till after this season.
Why do you want to change the cam?Do you know what cam is in the engine?What impeller are you running?If you buy a cam now and change the heads later down the road the cam most likely wont be large enough so you will have to buy another cam.I have not read that you were having problems if it is running reliable now save the money for the rebuild next winter.The 5 psi difference in compression is nothing to worry about.
I am not building a hot rod, just a nice reliable lake boat.
Thanks again, Alan
Famous last words. Any other jetters ever said these before "The Disease" set in?
As 502 said, you'll be happier if you make buys once, not buy new stuff to have to replace new stuff. You NEED pushrods. If you want a cam, try to buy the one you will need next year which should also work just fine this year. Unless of course you just have $400 to $1,000 to toss away (send me some then
One thing you need to find out is what impeller you have. Also, don't make the mistake of thinking "more cam = better cam" A jet is different from a prop or a car in that IT dictates your top RPM. Once you run out of HP to overcome the pressure in the pump bowl, you will get no more RPM. It will not "wind out" like cars & props can. If you over-cam, or over-head (or over-manifold) you will hurt the breathing and move your power too high in RPM to reach it, depending on what cut impeller you have.
With the right parts (good exhaust, un-choked heads, the right camshaft, 500 HP at 5,000 RPM is pretty easy to achive in a big block, the same parts (at least in my chevy) are working very well at 400HP (I need head porting).
Good luck to you. :boxed:
You say this now but wait till after this season.
Why do you want to change the cam?Do you know what cam is in the engine?What impeller are you running?If you buy a cam now and change the heads later down the road the cam most likely wont be large enough so you will have to buy another cam.I have not read that you were having problems if it is running reliable now save the money for the rebuild next winter.The 5 psi difference in compression is nothing to worry about.
502, my main reason for the cam change is the push rods not rotating. This tells me I might have problems develop later on.
Since I don't know anything about the motor inside or what I want to build my thinking is to go with a mild summit cam and lifter set for $90 bucks or so. Then when I know what I want to build I can spec out the cam I need.
And believe me I know what your saying about horsepower. I have a 62 Panhead that runs damn good for what it is but I just keep adding to it.
Alan
MS-
True about doing some research on a cam. you are only going to be turning around the 5k area. you want a cam which will develop max torque/HP in that rpm range. Most cams for a car are much higher than that, leaving you way shy of the max your engine has to offer.
Secondly, for the hp you are looking to achieve, the stock ford bottom end needs no tweeks. They are way different than a chevy. The only thing you might want to do is find a set of rods out of a truck engine for your rebuild. They are a lilttle beefier above the rod bolts than the ones out of an automobile engine.
Your D-3's are very capable heads for what you are wanting. I would suggest getting ahold of a member here "lakes Only". He does wonders with D-3's and usually has them available for swap at a reasonable cost.
Personally, I'd say trade the Edelbrock for a holly DP, and go with a single plane manifold. you don't need a dual. you will rarely be running in the rpm range where it's going to benefit you. and a single plane will give you better performance on the top end with a 460.
If you want a used cam, I've got a harland-sharpe jet-boat grind which I replaced with a much larger one. It's still in great shape, and I'd suggest going with at least a set of roller lifters. Way less friction, and an immeadiate 25 hp. gain. Also have a holly 750 marine DP that has been "massaged" by Duane at HTP. It's probably only got 2-3 days runtime on it, I suppose I'd consider selling.
Since your engine has D-3's I'm going to assume it is later than a '72, which is after they retarded the timing through the timing gears to comply with emmision-controls. If you will get a timing chain & gears to fit an early 429/460 (68-72) it will really perk up your engine! That would be the first thing I would do. Cheap, and a lot of gain for your bucks.
Hope this helps-
Ken F
http://www.hotboatpics.com/pics/data/3084/8787-5-05.jpg
How did you check the pushrods turning? At cranking speed, or with the engine running? If it's that big of a concern, pull the lifters one at a time and inspect the faces and cam lobes. The lifters should turn, and the lobe/lifter face should tell you what you want to know. If it all checks out ok, put in a new set of pushrods, then rotate the engine by hand while checking for any valve/guide/bind issues.If it's all good THEN, fire it. I'd rather get it on the water with a mild cam, then open a can of worms with a new cam and delaying my summer.
Assuming this is a stock, unmodified Hardin Marine 460 longblock (and so far it sounds as though it is...based on engine part numbers, c/r, max rpm, etc):
Your engine has 7.8:1 cmpression ratio, and so 125psi compression ratio is about right; leakdown not necessary.
It has approximately 325 realistic HP in good tune.
Your rods will suit this motor fine, no upgrades to the rods (or their bolts) is necessary.
Since this motor sat 3 years, it may be premature to believe that some of the lifters no longer rotate in their bore/lobe taper is gone. But if the intake is off, you can just as easily pull each lifter and inspect the top of the lobe for taper. (I wouldn't go here just yet and bet everything is fine).
Summit's mildest cam (SUM-3500) is not much better than the oem cam in your engine/won't make much of a difference on its own.
Since the season is here and you don't really know what you have for a motor, my advice is to inspect the components of the engine's factory valve train, replace the bent pushrods with good ones (I have them if you need them), fire the engine and see what you have at this point. It may be a good idea to just tune the engine, run it this season and see what you got, have fun this summer, and start thinking about upgrading in the next off-season.
The D3VE-A2A heads on your engine indeed have dismal flowing exhaust ports from the factory but can be ported and made into very good performing heads...certainly more than you need for your intended 400HP build. You have options as far as head choices. For example, if your shortblock is sound, you can switch to the D0VE-C heads and get 9:1 compression ratio with your current dished pistons. Or you can rebuild your shortblock with flat top pistons and your existing heads and get about 9.2:1 c/r. For just a top end upgrade, I'd recommend ported heads, roller rockers, timing chain, aluminum intake and Holley 850 carburetor. Rebuilding both the top end and bottom end is an altoghether different story. Feel free to contact me and ask any questions you may have.
I feel that a single plane manifold is the way to go on a jet boat; about the only dual plane I would recommend is the Weiand Stealth in CJ form.
If and when you decide to do your upgrades, I can recommend and/or sell you most of the parts to get your 400+HP. I have more factory iron heads in stock than most anyone/anwhere else I know and can port outright or exchange. I am almost always happy to offer fellow Ford enthusasts advice and point you in the right direction to accomplish your desires for your motor build...regardless of whether or not we do business.
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