Engine experts input needed on used engine
 

Finally got around to pulling apart my engines and would like some insight as to what I have. The engines started out as 94 502 mpis.

what I've found so far
Block - GM 8.2 cast on side
Crank - seems to be stock (cut) casting 14097044
Pistons - JE 757F
Cam - CC 3114 3110 HR114 and F5284 engraved into end and 139516 95C2B stamped into cam near one of the lobes.
Heads - Merlin 1-043B (345CC Intake / 119CC Chamber, Rectangular Port – Cast Iron BBC)
Lifters - roller joined by bar that says up (no other markings)
Push rods - 3/8" no other markings
Rockers - Crane Gold 1.7 ratio

Computer was done in 1997 by ASM but they have no record of what was done (sticker has date)

I'm starting to think these were set up as blower motors and when the boat was sold they pulled blowers and threw on stock flame arresters. I'm not much of a motor guy and trying to figure out what I bought. Thanks in advance.

You can find the book "rebuilding the Gen V/VI Big Block" on Amazon for Kindle- much cheaper than the hard copy version which is hard to find.

Search for ISBN B0027G6WY8 by Mike Mavrigan - has all the parts, castings, etc. Covers stock and GMPP parts, but is not a book on mega HP builds. Best $6 you will ever spend

or 1613250525 - not sure if this covers Gen 5 and 6...

I'll deff look into that thanks.

the cam is a comp cams hyd roller,call them with the numbers and they will tell you what it is.

can you post a pic of the top of a piston.

Running a bit rich

because of the carbon buildup it is hard to tell if it is a flat top or has a small dome.

Flat

probibally not set up for supercharger,but could work for a lower boost setup,normally a j&e blower piston will have .300 or more distance from the top of piston to top of first ringland,also the wristpin for forced induction is a .180 wall pin.

fixx
 

looks like a stock 502 mag piston,,someone may have cur a deeper valve relief.. and like mike said its a comp cam,,looks loke a custom grind,,they stamp the mass produced ones..

Thanks everyone, I'm at a total loss because I have no idea what I have. I'm
Guessing the cam will have some insight. What was weird to me was the rods were installed in the 1/5/2/6/3/7/4/8 order from front to back. I thought that's how fords were done?

Prostock,
The cam is a Comp:
Intake
281º seat
220º@.050”
.320” lobe/.544”valve/1.7

Exhaust
284º seat
224º@.050”
.333”lobe/.566” valve
This cam, matched to a 345 cc cylinder head, on a 502, makes for an interesting pairing of components.

Bob

Bob, any ideas what I'm left with after these specs? I'm not sure what my revs should be as well as assumed power. Somewhat of a stupid question but what's the difference between the 345 cc and 119cc listed on head specs? (I only machined and assembled turbo grand national motors so my knowledge of these things is limited.

That's a little more than; running rich. Without actually seeing the rings, it is hard to tell. The 502s had a issue with oil control, or you are sucking oil from the intake valve. How are the deposits on the stem side of the intake valve? Clean your rings off and shoot a pic from the side so, we can see the rings and also the cylinder bore.

If you have a 345 head on a 502. I will say in a NICE way; that was a bad choice! Mr. Bob Madara, will give you his camshaft, cylinder head , combination EXPERT TECHNICAL, opinion on that subject. I respect his; camshaft and cylinder head recommendations.
Mark

Can only post a pic at a time from phone.

Intake stem

Rings

Bore

Sorry about the piston, if see now it was not the stock one.
The intake valve, deposits are normal for something that is tired. I expected to see worst.
The rings look like they are doing their job, 2nd ring shows the shinny area on the bottom 1/2 of the ring. Deposits at 2nd ring lang, not showing much blow-by from top.
The cylinder bore, shows all the cross hatch, gone in the thrust area. How many hours since last rebuild?
Can you measure, the piston to cylinder wall clearance, check the bore for taper and excessive wear areas?
Check your ring end gap, top ring then check the 2 nd ring gap. Just curious, to see what they are.

I will have to reply later or someone else can, I have much to do.

My guess is the 345 is the intake runner volume and the 119 is the combustion chamber volume.

I think the 345 head is considered big for a 502 and the cam is pretty small. So having big heads and a little cam make for an "interesting pairing of components". At least that's how I'm reading it.

I will work on that once I get home from work. Hours since rebuild are unknown. They have 390 or so in total.

fixx
 

dont be misled on the 345 cylinder head,find out first where the 345 cc flows at what lift,,it may be .700 that the head flows at..and yes looking at the top of the piston looked stock but looking at the side they are after market which i have seen in the past that some j&e were used on 502 mags..

030630 Merlin 345 Iron .100 .200 .300 .400 .500 .600 .700 .800
Methods Used: flowed at 28" with a bowl blend 1" down 1" radiused entry plate on the intake port, No exhaust tube, Using Race Master valves
Intake 2.300" 77 145 213 271 326 366 389 374 Super Flow 600
Exhaust 1.880" 60 102 159 204 239 261 275 284 Super Flow 600

Thanks for your help, I ordered a bore gauge and digital caliper today to hopefully see where I end up. My original goal was to rering and rebearing the engine while figuring out what I have. Turns out whomever installed the intake manifold gasket completely destroyed it going in causing a massive intake leak on cyl 5 as well as letting water into block. Either over this current winter or prior to my ownership the cyl sat with water in it causing it to pit badly. So I'm either going to sleeve it or get a new block. On to engine 2.

I broke down #2 tonight and found out its a much newer block and has been rebuilt much more recently. Cross hatch is completely in tack with almost no wear. even the pistons look much better. Maybe it froze and a new block was installed. Casting number shows its an early gen 6 block (doesnt have 6 bolt timing cover)

I was running 87 octane with timing set at a base of 8 degrees. Should I have had much more timing and 91/93?

fixx
 

i hope you ordered a sunnen bore gauge lol...all bs aside,your best bet is to take it to a machine shop and have it checked,,i still see cross hatch from the honeing stones at the top of the cylinders..if you dont have a big ridge then you can most likely get away with rings and bearings but if it were me i would do the whole ball of wax which is a full bore hone line bore decking..you dont know what they been through so why not..or just wait for a nice pair in the swap shop..as a fact their are a couple nice pair on their.

Haha, I don't have sunnen type money. I believe the honing set that I use is sunnen though. Depending on the condition of the block I may scrap it and find a early gen 6 to match the other. One had water sitting in the cyl causing it to pit. So it's either a sleeve or used block so I don't have to buy new pistons. I'm very apprehensive of bringing anything to a machine shop because of having no control of their work. When I worked in one I took care to make sure everything was perfect, my coworker, not so much. Time will tell what happens. I'm currently writing Bob in help of getting myself a set of cams that may work with my set up. At least one of the two engines is in decent shape. Pic is of engine #2

I see what you are saying. I will be the first to say I am new to bbc and I'm here to read and absorb what I can to make my boat better and faster. I was more or less guessing at an interpretation of what bob meant by interesting parts list.