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Starting engine rebuild and would like advice


Will_982

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I am starting on an engine rebuild to go into my 72 240 and would like to have some advice. I got my hands on a 75 280 block with a n42 head, I have it torn down to start on the rebuild then by spring hopefully have it swapped into my 240. I would like to get as much power out of it as I can but at the same time not just burn money. My location yields me little to no help from local machine shops on advice on getting the most out of an engine this old.

 

From research and what parts I have on hand I have decided to keep the n42 head on the l28 rather than swapping with my e88 but I will be keeping it a carbureted engine. (I am in process of switching it over to electric fuel pump.) My questions are, wether or not I should spend the money to go to a flat top piston once I get the engine tanked or are horse power gains just not worth the money? Anything else that might gain me some more power but would like to keep parts below 1000$?

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Well your budget is tight, so I would just shoot for a freshen up of the n42 stuff and throw in a cam. Flat tops would be better for a hot cam, but I think you will blow thru 1000$ pretty fast. Get some electronic ignition and concentrate on a good tune.

And search until your eyes bleed. 

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"Search until your eyes bleed"

 

^That man speaks the truth.

 

$1000 is really tight, I know you said just parts, but are you factoring in the labor involved?

 

Machine/inspection work:

Deglazing the cylinders

Hot tanking the block

Decking the block

Decking the head

Shimming the head after deck

Removing stuck studs/bolts

Testing/balancing/checking crank, piston, rods

Surfacing flywheel

 

Then the parts:

Rings

Rod bearings

Crank bearings

Engine bolts

Timing kit

Water pump

Freeze plugs

Oil pump

New studs for intake/exhaust manifold

Assembly lube

Micrometer or the torque tape width thingy

Break in engine oil

Quality filters

Engine oil

Coolant

Thermostat

Engine seal kit (valve cover, head gasket, oil pan seal, water pump seal, timing cover seal, crank seal, rear main seal, etc etc)

 

Potentially new pistons and rods

 

Not to mention it would be a bit silly not to do the clutch and do a transmission flush and fill while the engine is out.

 

Not sure if that is really possible.

 

I would be concerned with flat tops as with the rise in compression, the factory carbs are not going to look like quite as good a solution, you would either need the carbs rebuilt with new needles or would need to look at either a 4 barrel conversion or a triple webber/mikuni setup and that would blow your budget right from the start.

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I think every rebuild I have done myself cost $1400-1500 in parts and machine shop. For budget, I say keep it stock and invest in intake and exhaust as required. A little "free" power can be had by port matching manifolds and blending the port into the valve seats on some heads.

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Thanks for the replies, think I will be keeping it dished pistons. The l28 I got is in amazingly good shape inside but the entire fuel injection system was torn up by field critters from sitting so long, thus reason for keeping it carbureted. I have already ordered seals, head bolts and all the little stuff that adds up up quick but saw roughly 300$ for flat top pistons and didn't seem to bad. Did the engine builder program and saw roughly 9.6 compression with flat tops and was concerned if that would open up a whole new set of problems.

 

The z I have right now was born an auto so this is where it all started. I just did some side work to acquire the trans and engine came with it for nothing, figured would like to do it right first time.

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