new engine build or buy long block ?

[UKandH]

If i was rebuilding to a budget then go to Falcon Performance (falconglobal on ebay) If im rebuilding with quality parts at reasonable price i.e. not Summit racing, then i use Falcon every time. $400 USD for a master rebuild kit which includes:

Cast piston rings
Rod Bearings common sizes available
Main Bearings common sizes available
Cam bearings
Full gasket set
3-piece timing set
Oil pump
Sealed Power OE replacement cast aluminum piston set - most common sizes available
Expansion/freeze plug kit
OE specs replacement camshaft
Lifter set

They will build a kit for you for the PCM application, but that price is about usual for them.

Just my 2 Cents worth

[lively]

so what about intake ? ive been lookin at the edlebrock rpm intakes , and possibly heads dart or gt-p ? what are the differences or gains

[UKandH]

The RPM intake is for higher RPM ranges up to about 6500 revs, our engines max out at 4.5 to 5K so the RPM manifold is not the right selection unless your building a drag boat
I would go for the Performer or the Performer Air Gap as they are better suited to low down torque gains and better fuel distribution, the Air Gap manifolds also help isolate the hot engine from the carb to help with hot starting. If it were me building this motor then i would be buying the Performer Air Gap as my first choice.
Dart heads are great, but it depends on your budget mate.

Again if it was me it would be Dart and Performer air gap. It may be a good idea to talk to dart and see what manifold they recommend

[cadunkle]

I was going to reply to this thread some time ago but been too busy to build an engine on paper. A solid rebuild can be done in the $1500-$3000 range depending on your goals. I haven't built a small block in many years, just a few big blocks, so I'm not up on the latest and greatest and don't know figures like typical chamber size, pistons, etc. off the top of my head.

First step is figure out what heads you're going to run. I wouldn't run stock heads on a small block since aftermarket heads are so cheap. You'll be in $500+ machine work to do guides, cut seats, surface, and whatever else your heads need and they'll still flow like crap. TFS has aluminum assembled ready to run heads starting under $600 and you won't need to port them. I wouldn't waste time or money on stock iron small block heads.

Figure the chamber volume of the heads you will run. This will give you an idea of the piston dome or dish required to get in the ballpark for compression ratio. You'll want in the 9-9.5:1 ratio since I'm assuming this will be a torque build. Determine your cam choice. I suggest something with a longer exhaust duration, don't go crazy with ramp rates since this engine will see sustained high RPM. Comp has a good XE and marine line of cams that may fit the bill. I like Lunati Voodoo line of cams, steep ramps and high lift, but not suitable for this application. Peak power by 5500-6000 RPM, no more or you'll be sacrificing torque and economy.

Once you know what heads you're going to use and have a cam in mind, figure what dish/dome is required for a dynamic compression ratio in the 8-8.5:1 range. Bottom of that range for 87 octane, top for 91. You can push more dynamic compression and get better torque and economy but you may need more octane or a less than optimal timing curve. A ski/wake boat engine is not the place to skirt the line on detonation due to sustained load and noise which may make hearing detonation difficult while tuning.

Run marine head gaskets since you'll have raw water cooling. I see FelPro are .049" compressed thickness. You'll want to select a piston with compression height to get your quench in the .030"-.040" range to avoid detonation and get max power and economy. This would mean .019"-.009" above the deck. You may need to deck the block to accomplish this. Or there may be other suitable head gasket choices. A lot of this will be choosing and compromising on the parts to achieve your goals. Sometimes you compromise a bit with available off the shelf parts or to avoid particularly expensive parts that would get you closer to ideal.

Another thing I'll add is I've cheaped out with hyper pistons in the past and always regretted it. I would do forged if you intend to keep this boat a long time. There is much peace of mind in a rock solid bottom end.

Plenty more to it, but you gotta start with heads/cam/pistons. Do you have any particular power or performance goals for this build? Let me know about heads. I can help with crunching numbers on compression ratio, compression height, piston selection, etc. and if I have flow data for the heads run it through Desktop Dyno.

[lively]

ok so what i want is 300-350 hp with same if not more torque.. im clueless on numbers valve lift , cam profile ect .. let me tell you what i want to do for my budget

send short block out to be line honed and bored over 0.40

new pistons , bearings , cam ?

ebay has full kits for 450$ is this a good idea or should i just trust machine shop ?

balance crank and rotating assy

deck block/ heads

run gt40p cast / aluminum ?

can i pick any aluminum heads ?

edlebrock air gap performer

i already have a 600 cfm edlebrock marine carb

new cir water pump

new fuel pump

paint/ install


i am clueless on what to buy for power , now with that being said i really just want the machine shop to assemble the bottom end , but will i need diff push rods ? for diff heads?

[lively]

oh and mine current 351w is spitting like a lama out the dipstick , lol 20 psi oil pressure at 2k rpm .. i changed to 20w50 to help but really no change ... motor is done and im ready to spend more money !! ha ha .. just bought a new tower and Bimini so that will go on this weekend .. but my budget is gonna be 2500 +/- 300 ..... lol..

[cadunkle]

Why .040" over? Heave you measured taper? Go least oversize required to make it straight and remove any damage. .030" gives you the most options for pistons, sometimes cheaper than other sizes.

I see the $450 ebay kit... I wouldn't touch it without having a list of brand and manufacturers PN of each component. Probably fine for slapping together a stockish low output engine but I wouldn't use it. You're paying for machine work, don't waste that money by saving a few hundred on decent pistons and other parts. To cheap out like that I'd sooner pull it apart and as long as taper wasn't ridiculous just hone it as even as I could and slap new rings and bearings in it.

I'd be tempted to run TFS 170 heads, good flow and reputation from what I read.
tfs-51410002-m61 - $1125

These head gaskets are smallest compressed thickness (.040") I saw at a glance suitable for marine use.
fms-m-6051-cp331 - $77

These pistons would be my choice at a glance. Forged, suitable 14cc dish for those 61cc TFS chambers to get you .013" in the hole at factory deck height for 9.47:1 compression at .053" quench with those head gaskets. Not excessive, but would be better zero decked for 9.75:1 though that may be pushing compression a bit. I'll have to run dynamic compression with some cams and see where it falls.
srp-149606-8 - $620

if you want cheaper pistons you could run hyper KB-303. This puts is .023" in the hole for 8.79:1 at .063" quench. not much squeeze and getting close to detonation prone. Zero deck it and you're at 9.22:1, a good ballpark for a marine engine that will be running a mild cam and shouldn't be detonation prone.
kb303-030

I'll have to run some dynamic compression numbers and plug it in DD, but your goals are reasonable.

[lively]

What I need is a reliable engine with some punch . Give me a full lay out on what you would do short block to heads for 2500$ range . I haven't priced machine work yet but I want the engine to be strong in the lower end and be balanced as possible , I've seen those trick flow heads they are sweet . But are they necessary to obtain 300-350 hp ? I don't want any detonation other than when the spark plug is lit ! Run your numbers and let me know what you come up with .. Probably will pull the engine next week to get started on the tear down . I've been reading up on reviews on MS around town trying to talk to a few for the best work ...

[cadunkle]

Here's more or less the parts for what I would build...

Clevite Engine Parts CB831P - Clevite P-Series Rod Bearings - $55.76
Clevite Engine Parts MS1432P - Clevite P-Series Main Bearings - $52.97
Clevite Engine Parts SH510S - Clevite Camshaft Bearings - $25.97
Fel-Pro 17360 - Fel-Pro Performance Marine Intake Gaskets - $24.97
Fel-Pro VS50068R - Fel-Pro PermaDry Valve Cover Gaskets - $10.97
Ford Performance Racing Parts M-6051-CP331 - Ford Racing Performance Cylinder Head Gaskets - $76.97
Ford Performance Racing Parts M-6710-A351 - Ford Racing Oil Pan Gaskets - $22.97
JE Pistons S100S8-40305 - JE Pistons Pro Seal Premium Sportsman Series Piston Rings - $99.46
Melling IS-83 - Melling Heavy-Duty Intermediate Driveshafts - $12.97
Melling M83 - Melling Oil Pumps - $41.97
Sportsman Racing Products 149606-8 - SRP Ford Small Block Dish Top Pistons - $619.68
Trick Flow Specialties TFS-51400510 - Trick Flow® Roller Rocker Arms - $289.97
Trick Flow Specialties TFS-51410002-M61 - Trick Flow® Twisted Wedge® 170 Cylinder Heads for Small Block Ford - $1,125.00

Part Subtotal $2,459.63

You'll be + $200 for cam and lifters, and about another $100-$200 for pushrods, gaskets, misc bits. Machine work pricing is highly variable depending on region, as well as what your engine needs. $500-$1000 is my guess. So $3500-$4000 to do it with nice heads. Can probably shave about $500 cutting corners on parts, but I would want to build a solid bottom end as top priority as top end is quicker and easier to change is desired.

Anyhow... Some numbers for power and compression with two different cams and zero deck vs .013 in the hole.

Comp XE 262/270 .013" piston to deck


Comp XE 262/270 zero deck


Comp XE 256/262 .013" piston to deck


Comp XE 256/262 zero deck


The 262/270 is about as big a cam as I'd go for a towboat with stock manifolds and displacement. Idle will be slightly higher than stock and slightly noticeable but should not be too obnoxious in a 351w. The 35-235-3 XE 4x4 cam is interesting too Sacrifices some top end HP but more HP at lower RPM and slightly flatter torque curve.
Comp has some "marine" grinds there's not split duration. Simple old style cams. The 31-216-2 is a 260/260 and compares to the XE256/270 but leaves at least 10 hp and ft/lbs on the table at all RPM and doesn't have quite the potential when uncorking the exhaust. The 31-218-2 is a 268/268. I'd expect it to maybe have a slightly rougher idle than the XE 262/270 as it has more overlap. HP is similar at peak but less at lower RPM and it's down a bit on torque from the XE split duration cams. Didn't run dynamic numbers on any of those.
Personally I'd be tempted to run the XE 256/262

Note that exhaust is the biggest restriction. I put HP manifolds in as marine pyramid exhaust flow better than logs, but a far cry from a true performance manifold or header. Changing exhaust to headers in DD is 50+ HP more with pretty much any cam.

What heads do you currently have? To get the price tag down under budget the heads are not an option. Heads and associated costs are adding about $1500 to the price tag. Machine work on your heads (cut seats, new guides, new valves if/where needed, surface if needed) I would expect to be in the $500-$700 range. Also figure on +$100 for valve springs for the cam vs the already assembled heads.

Let me know what your head castings are and if I can find flow numbers I can see what they will do. I'll also see about checking GT40 and GT40p heads.

[chris young]

Wow, that's cool, offering all that advice Cadunkle! I'm no where ready to do a rebuild on mine, it seems to be running well enough for now, but I have toyed with doing it in the future. I will definitely bookmark this thread.