BBF Engine Build - Help

[Swath]

Victim of a water pump failure!! Got the call Friday from the machine shop that the block has a bad crack and the heads are toast so it's time to start over.


I need some help as I've never built a marine engine before. I know it's a different engine than a street engine, needs to make all it's torque in the low range to 5K rpm but could use the groups input on blocks, heads and such.


Boat is a 1990 22' Classic with a King Cobra drive (hump). Old motor was a BBF 460 that was suppose to be a performance engine (previous owner paid $15K for it but got taken, when I tore it apart is was nothing special). Looking for 80MPH and as indestructible as possible. I'm on Georgian Bay so fresh water and good waves.


Looking for something in the 600HP range when complete. I'll reuse the carb (new 850 Barry Grant Demon carb last year), Edlebrock RPM intake and aluminum GLM exhaust with stainless risers.

For the new block I'm thinking an Eliminator Sportsman with 4 bolt mains. Planning to go to 532 cubic inches so bored 30 over. I know the block is overkill and I could use a stock block but I want to do this right.

For the internals I'm thinking the SCAT 4340 forged crank, SCAT forged H beam connecting rods, premium forged dished pistons.

For the heads I'm considering Flow Pro stage 3 CNC ported aluminum heads, 95cc (will give me 8.6:1 compression) with 2.19 S.S. Intake and 1.71 S.S. exhausts.

I have not figured out what cam would be right for this set up. Suggestions? Also not clear on what lifters should be used.

Anyone have suggestions? If anyone has built a similar engine I'd like to know what you used and if you're happy with it.

Oh and I'm not chancing to a BBC or a Merc drive!!!

[JayZ]

,...So why not change to BBC? seems to me it would be money better spent. -cheaper and more parts available and resale will also be much better. You also need to think about all the money you'll be putting into an engine that is in front of a drive (although believed by many to be superior to a bravo in many ways) that is also hard to get parts for. ...Try getting your head around external steering from a King Cobra drive. It can be done but there is not an off the shelf kit out there.

I can't comment on your build sheet but I can tell you there are lot's of cook book recipes out there for the BBC that are tried and true.


Good Luck!



Victim of a water pump failure!! Got the call Friday from the machine shop that the block has a bad crack and the heads are toast so it's time to start over.


I need some help as I've never built a marine engine before. I know it's a different engine than a street engine, needs to make all it's torque in the low range to 5K rpm but could use the groups input on blocks, heads and such.


Boat is a 1990 22' Classic with a King Cobra drive (hump). Old motor was a BBF 460 that was suppose to be a performance engine (previous owner paid $15K for it but got taken, when I tore it apart is was nothing special). Looking for 80MPH and as indestructible as possible. I'm on Georgian Bay so fresh water and good waves.


Looking for something in the 600HP range when complete. I'll reuse the carb (new 850 Barry Grant Demon carb last year), Edlebrock RPM intake and aluminum GLM exhaust with stainless risers.

For the new block I'm thinking an Eliminator Sportsman with 4 bolt mains. Planning to go to 532 cubic inches so bored 30 over. I know the block is overkill and I could use a stock block but I want to do this right.

For the internals I'm thinking the SCAT 4340 forged crank, SCAT forged H beam connecting rods, premium forged dished pistons.

For the heads I'm considering Flow Pro stage 3 CNC ported aluminum heads, 95cc (will give me 8.6:1 compression) with 2.19 S.S. Intake and 1.71 S.S. exhausts.

I have not figured out what cam would be right for this set up. Suggestions? Also not clear on what lifters should be used.

Anyone have suggestions? If anyone has built a similar engine I'd like to know what you used and if you're happy with it.

Oh and I'm not chancing to a BBC or a Merc drive!!!

[MOP]

Good advice to swap to a Chevy! All you need besides the obvious is a OMC GM bell housing, you will save $$$ as Ford parts are more expensive and tougher to find. Check all the various boards you may find an HP 500, that will get you a tad faster than your 80 goal.

One example of many the engine bolt pattern is standard to all GM blocks.
http://www.ebay.com/itm/OMC-Cobra-bellhousing-aluminum-for-4-6-and-8-cylinder-engines-/230682873214?pt=Boat_Parts_Accessories_Gear&hash=item35b5c54d7e&vxp=mtr

[Swath]

It is tempting but I had already bought a bunch of other parts to rebuild it before I found out the block and heads were cracked.

Before I decide one way or the other, that bell housing you sent, would it work for a big block chevy? I assume the only thing I would need to make the drive work is a different drive shaft.

[MOP]

Oddly enough I believe the drive splines are the same, you would need a coupler. Either way judging by the age a new couple is in order especially with bigger power. I happen to like the 460, go on some of the Ford sites to see what would be you best cylinder heads. There are a few decent cams, I do not know which to recommend.

[Swath]

Met with the machine shop today and will be making a few alternations to the plan.

First is we're looking at 521 CI rather than 532.

Second is he's suggesting I stay with a stock ford block and put the money saved into Edelbrock aluminum heads.

We talked about the change to a BBC engine and he felt it was a waste of money since resale value is not a primary concern. Also All the other parts I already have become useless.

[duckhunter]

I kinda like the idea of going with the BBF dinosaur-size motor. Should go great with your KC drive. The 385-series Ford engines are sturdy and can be built for a ton of power and torque. Since you already have a pile of parts it makes a lot of sense.

Bob Madera at Marine Kinetics is supposed to be THE marine cam guru - he can probably point you in the right direction and custom grind something for your exact application/configuration. Aluminum heads seem like a good idea; save significant weight, better heat transfer allows for higher compression, etc. Are you fresh water cooled? If not, with a new block and heads now's the time!

Let's see some pictures of this beast as it gets built!

[gcarter]

This is something I'm sure you know, but Hardin marine offers exhaust spacers to bolt on any BBC exhaust to your Ford heads.

[duckhunter]

This is something I'm sure you know, but Hardin marine offers exhaust spacers to bolt on any BBC exhaust to your Ford heads.

That's a great point - I imagine finding BBF performance exhaust could be a challenge.

[Swath]

I actually already have the Ford to Chevy adapters from the existing motor. This will let me keep my current exhaust.

Just an update as this evolves:

Going with a stock Ford block with a Scat 4340 forged crank and Scat forged H beam rods.

Heads will be Kaase P-51 heads. Just have to figure out the pistons. Big decision is what compression ratio I need using 91 octane fuel. There is a lot of discussion but it's hard to find anyone with big block ford experience to comment. I'm thinking about 9.5:1 would work, anyone care to comment?

I'm hoping to order the short block from CNC Motorsports in South Dakota this week. I'll build it up from there myself.

[Sidney073]

I've been a "Ford guy" all my life, and have built quite a few strong running engines. The 460 Ford is a very strong engine, and can be built for not much more (if any) than a BB Chevy. I have built performance Fords “back in the day!” with Chevy parts because no one made anything for Fords!
With the newer technology out there many "Old School" thought processes have changed, among them is compression ratio. I would recommend between 9.5 and 10.5 to 1, higher compression ratios can be ran with lower octane, and ethanol blended fuels by limiting your total timing. I would discuss this with your Cam Guru, who ever that may be, for their recommendation, then read your plugs after break in has been completed and you can make some real world runs to finalize it. I would keep it conservative for break in to be safe.
One note on reading plugs, if you get an Otoscope, the instrument used by Ear, Nose, and Throat doctors to look in your Ears, you can read the "Firing Ring" to set your timing. This "Ring" can be seen on either the Center Electrode porcelain insulation, or the outside body of the spark plug. The ideal position for it is at the base of the porcelain insulator. This is the method I have used on a friends race car and worked great, prevented having too much timing and burning pistons and spark plugs, as well as not enough and performance suffering. One final word on timing, and I’m sure you know, Higher Octane = More timing possible, Ethanol Blended = Lower timing possible.

Hope this helps,
Sid

[MOP]

Sidney why are you screaming!

[Sidney073]

I don't know what happened, it came out like that, I tried to change it to smaller but couldn't get it to change. Just tried again, and it changed. Didn't mean to scream.


lol, Sorry,
Sid

[Swath]

Just an update, John Kaase racing has completed and shipped the heads, custom grind hydraulic roller cam shaft, billet oil pump and modified double roller timing chain.

CNC Motorsports will be building the 532 cubic inch block up in 2 weeks.

Heads are being finished out with Comp Cams Pro Magnum XD roller rockers and matching roller hydraulic lifters.

This new motor will be topped with a Edelbrock Performer RPM air gap manifold and I'm reusing the Barry Grant 850 carb I already have.

Next summer should be interesting as this motor should easily make between 600-700 hp. Not much on Georgian Bay is going to get past me!

For those that believe Ford big block parts are either expensive or hard to get, that might have been the case years ago but now it's just as easy as building a BBC. Exhausts are no longer hard to find either as they make several high performance sets specifically for the BBF bolt pattern.

[MOP]

Sounds like you are coming along great, looking forward to the spring report. As always enjoy!

Phil

[Moody Blu']

be careful with the cam and keep it in mind that you may need to make it dry exhaust with mufflers.. I watched cnc motorsports dyno runs and they know how to build strong motors. No doubt your gonna have a robust motor...

Id say stay low on the compression side so you can bolt a charger or turbo/turbos onto it if you want otherwise the extra power you get form higher comp is gonna cost you more if you decide to force induct it later on(changing compression ratio)

stick with the ford. they're better anyway ;)

I spoke with allen at hi tek to make a custom set of headers for the 383 in my girls boat with larger and longer tubes all equal length, possible turbo bolt adapter as well as dry exhaust straight to the tips and water cooling through separate pipes.. may want to give him a call. sounds like you got some good mods ready.

[joseph m. hahnl]

I actually already have the Ford to Chevy adapters from the existing motor. This will let me keep my current exhaust.

Just an update as this evolves:

Going with a stock Ford block with a Scat 4340 forged crank and Scat forged H beam rods.

Heads will be Kaase P-51 heads. Just have to figure out the pistons. Big decision is what compression ratio I need using 91 octane fuel. There is a lot of discussion but it's hard to find anyone with big block ford experience to comment. I'm thinking about 9.5:1 would work, anyone care to comment?

I'm hoping to order the short block from CNC Motorsports in South Dakota this week. I'll build it up from there myself.

First and for most the compression ratio is based on the volumetric efficiency of the cam shaft. 9:5:1 is low and would very doubtfully push 700 Hp. A few tips aluminum heads allow 1/2 point of DCR or 1 full point of static compression ratio . The longer the duration the cam the lower the DCR the more static CR is needed

My set up has a Static CR of 10.2 :1 the Dynamic CR is 8.2:1 and runs 87 to 93 octane









Not recommended



Regular 87-89


Supreme 89-91


Premium 91-93


Race Only




below 7.0


7.0-7.7


7.7.0-8.4


8.4-9.1


above 9.1








The ideal DCR range for a performance motor on pump gas is 7.5 to 8.5

http://classicinlines.com/CompressionRatio.asp

[joseph m. hahnl]

be careful with the cam and keep it in mind that you may need to make it dry exhaust with mufflers.. I watched cnc motorsports dyno runs and they know how to build strong motors. No doubt your gonna have a robust motor...

Id say stay low on the compression side so you can bolt a charger or turbo/turbos onto it if you want otherwise the extra power you get form higher comp is gonna cost you more if you decide to force induct it later on(changing compression ratio)

stick with the ford. they're better anyway ;)

I spoke with allen at hi tek to make a custom set of headers for the 383 in my girls boat with larger and longer tubes all equal length, possible turbo bolt adapter as well as dry exhaust straight to the tips and water cooling through separate pipes.. may want to give him a call. sounds like you got some good mods ready. Actually you build it high CR with a small combustion chamber, and then if mechanical aspiration is desired you change the heads to a larger combustion chamber.:biggrin.: because at that point, heat resistant larger valves are in order:kingme: