Oldsmobile 374 stroker build

[Olds 307 and 403]

I have decided to work within my budget and not go with the 403 build. It will be an iron head, roller cam, Olds 350 with a 4.125" bore and 3.5" stroke and a 2004R and 3.90 posi for my 70S. I already contacted Parkland Engine Builder's for machine shop price. I plan to have it stripped out by Christmas Eve and hopefully drop it off, there will be a wait. It will come at a great cost but there will be some benefit for all you guys, you will see.
My current parts run down
completely untouched 76 short block
330 forged steel crank offset ground to 3.5" stroke by Ohio crank.
Scat sbc 6" long, 2" journal rods and rod bearings
Clevite cam bearings
ARP 7/16" head bolts
ARP 1" longer 302 main studs for a Halo or girdle. FYI 302 main are the same length as 1-4 SBO mains.
1/2" CNC Halo, better made than the J+S Halo
Hydraulic Roller lifters
I also have Performer and RPM intake. I also have a 1" open aluminum spacer, modified for less air restriction. I may try the spacer on the RPM intake.
Fully rebuilt with a couple of thousand miles #6 iron heads 2.07/1.56 valves,with positive seals machined and the bowls opened with a bowl hog cutter. I am pocket porting them over the next couple of weeks, may do a separate thread.
Comp Cams 1.6 roller tip and Scorpion 1.72 full roller rocker arms, both for 3/8" studs, guide plates and 5/16" to 3/8" conversion studs.
Everyday Performance custom 800 cfm Qjet with adjustable APT
Mallory Breakerless distributor, adjustable mechanical and vacuum advance, set to 18 mechanical in by 2800 and 11 degrees of vacuum advance.
Mallory Hyfire 6AL with adjustable rev limiter, will set to 6000.
Serpentine belt drive and new Flowkooler Billet impeller, reverse rotation water pump on the way
New A body replacement aluminum/plastic rad
Dodge Stratus Fans
Good TH2004R trans, 86 model appears rebuilt, shifts perfect, needs upgrades.
PATC 2200 to 2500 stall, flashes at 2350 stall and deep trans pan with drain plug and a stacked 5000 rpm governor modified by me.
Sanderson shorty headers with custom 2.5" X pipe dual exhaust with shitty 2.5" tail pipes. Terrible job with a terrible price. I should have bought Flowmaster tail pipes and installed the tail pipes myself. Hack jobs like this is why I do all the work on my own cars, all 5 of them. I will add an O2 bung for a wideband tuner.
Remember these are the parts I HAVE, not what I want or need.

 

[Olds 307 and 403]

Ready to pull

Going to start pulling valves soon.

 

[Olds 307 and 403]

I found a Mahle 2618 forged 4.065" bore, 7.9cc dish, 1.550" compression height, 1mm/1mm/2mm ring pack piston. That equals 363 CI, interesting. The Icon piston is also 2618, older 1.5mm ring pack and 15.2cc dish, needs 62cc chambers for 9.6 to 1 with 0 deck, even with the larger bore. I would not mind polishing the combustion chamber, nice and smooth. According to the compresion height calculator, with the 3.5" stroke and 9.33" deck height, a 1.58" compression height is needed. Either piston is .019" to .030" in the hole. If this is right, I would deck it .020" and use a .030" MLS head gasket. Not looking for a max ci build, using the huge pile of parts I have for a reliable, cool running street and maybe a once or twice a year strip build. The bores look really good, hone to fit should save some $$$, will see what Parkland Engine Rebuilders say.

 

[Olds 307 and 403]

Motor out, all pulled apart. All the rod bearings were scored, surprisingly the bent rod bearing was no worse. The cam had multiple lobes with wear compared to others, failing on multiple lobes. Not bad for a 45+ year old short block, $120 for the complete 76 350 with great oil pressure and comp, ran for probably 5 years. Fully rebuilt #6 heads with 2.07/1.56 valves with a bowl hog cut, $400 cost, was $1200 worth of machine work and parts supposedly. It was $225 US for the cam and lifters. I used the garbage Cloyes Street roller timing set, they were slack new, not going that way again. A pile of snow Tuesday so I will take the block Christmas Eve, if they are open and the call goes well tomorrow.

 

[Olds 307 and 403]

Well all the bearings were toast, just the rod bearings were worse. Intake valves are 2.07 confirmed by the caliper. They are close to the edge of the chamber. There must be a burr on the edge of the exhaust valve, could not pull the valve out, moves fine till the very edge

 

[Olds 307 and 403]

Talked to Parkland, talked to Dean I believe. They are open till Wednesday and then closed to January 4th. At least a couple weeks till they can touch it. I will try and kiss the wife nice for her to drop it off or I will take Wednesday off. The wrench in it all, there is supposed to be 40 cm of snow tomorrow. Our family is famous for going out in the worst conditions possible. I guess the 4x great Uncle, Dr John Rae, the Arctic explorer, is a part of us.

 

[Olds 307 and 403]

I did a quick clean up of the oil pan and put it back on the motor, so it won't be sitting on the mains during transport. The SB pan clears the Halo, which is good, the BBO replacement pan should allow a little more room. I will lay down a tarp, put the motor in the back on a tarp and another tarp over top weighed down. I will fog the motor with storage spray. I am hoping my Wife can drop it off tomorrow but it will depend on road conditions.

 

[Olds 307 and 403]

Block at the machine shop, it may take a month, they are busy.

 

[Olds 307 and 403]

These parts arrived today. I am installing the fan controller this weekend. I am leaving the rad for the new motor. Speaking of that, still no word from the machine shop, hopefully soon so I can order pistons. FYI, I have $1000 just for the starter, rad and fan controller. The strokes and ground undersized 330 crank, 1/2" Halo and studs, another grand.

 

[Olds 307 and 403]

Well guys, I will try and renew this forum. After a near 7 month, back and forth with Parkland Engine Builder's, I picked up this. 4.100" bore, decked .016", will leave the pistons .003" above deck. Using .042" Edelbrock head gaskets will give .039" quench and 9.65 to 1 compression.

They still haven't ground my stock stroke 330 crank which measured standard on the mains by my rough caliper measurements standard mains and .020" on the rods. No what it was supposedly ground .010" mains and .020" rods. It will need ground to the next undersize for .0022-.0025" rods and .0025"-.0028" main clearances. That will provide get pressure with 10W30. Cutlassefi sent the Molnar rods, 218/218 .525"/.525"roller cam and Canton pan and pick up, it should be here shortly. I recieved these yesterday, really nice. Mahle 4032 4.100" coated 1.625 compression height, full floating pins, 1mm/1mm/2mm ring pack.

 

[Olds 307 and 403]

I decided to blast a few of the parts. The filler tube wasn't bad but oil filter adapter cover were. I taped off the oil filter adapter openings and both ends of the oil fill tube. I also painted the Flowkooler water pump, it had basically no rust on it.

 

[Olds 307 and 403]

Ok, so I ran a 7/16" tap in 1 through 4 mains, cleaning after each hole and a 1/2" tap in #5. I then hit with carb cleaner and blew them out with compressed air. I installed 1-4 hand tight as ARP specifies. I used a Die on the 1/2" bolts for #5. I hit all the the blasted parts with clean cleaner, compressed air then brake cleaner. Then VHT Gold metallic engine enamel, multiple light coats. I tapped all the bolt holes in the block. I cleaned the intake end rails, timing cover gasket surface, oil filter adapter area and pan rail gasket surfaces on the block the finer 3M conditioning pads on my Dewalt drill. I also carefully treated the outside of the block with rust converter, wiping even tiny drips off the machined surface immediately. Next will be the dowel pins, anything special to install them? I see one in timing cover area is half pulled out.

 

[Olds 307 and 403]

Machine shop just called, it looks like the 330 crank was ground .020"/.020" undersize. I was told.010"/.020" years ago when I bought it off Ebay. They were puzzled after measuring due to no stamping, my offset ground 330 crank is stamped. Oh and I can use these studs with these rocker arms. Notice how much shorter the Harland Sharp Polylocks are than the Comp Polylocks.

 

[Olds 307 and 403]

Christmas in July! The machine shop called my 330 crank is .020"/.020", was supposed to be .010"/.020". Either way it will probably have to go .030"/.030" undersize, sounds like they may actually grind it. I will be dropping off the pistons and rods for balancing this week.

 

[Olds 307 and 403]

Good thing I checked the pistons and rods. I thought when the pins are floating they just go into the rods. They do not fit as is, the small end needs honed to fit the pin. Apparently this is the norm according to Mark. The rods look to be around 800 grams but this little scale is acting goofy.

 

[Olds 307 and 403]

Well after a long 11 hour day of fun at work, I went looking for my other balancer off the 403 to replace old denty. Found it, blasted off the Duplicolor with aluminum oxide and painted with a couple of coats of VHT Black Metallic Engine Enamel. I also removed 20 pounds in the form of the removal of the POS R4 compressor.

 

[Olds 307 and 403]

More

 

[Olds 307 and 403]

My Wife dropped off Mahle Pistons and Molnar rods at the machine shop to have rods honed fit to the pins, now they can weigh for balancing, along with a balancer and flex plate. Incase they want it but should not need it for internal balancing. Will see if they can complete it before the end of the year. Oh, I ordered an Edelbrock top end for a fair price off Ebay to get the .042" thick head gaskets. Well, they are no longer the white head gaskets, they are now standard blue Felpro .041" head gaskets, fine, will give me .038" quench. The valve cover gaskets look to be the same material as heavy duty Felpro pan gaskets, latex covered cork without the rigid core, at least not that I could feel. Maybe Mr Gasket Ultraseal?The intake gaskets are the nice rubber bead around the ports and the exhaust gaskets a fiber material. Not a bad price with the free shipping through Amazon. I also received the carb cleaning brushes, they should work quite nicely in the block passages.

 

[Olds 307 and 403]

Oh and it looks like all clearances will end up around .0025", piston to wall, the Mahle clearance at a 4.100" bore. I also told the machine shop I wanted .0022 to .0025" rods and .0025 to .0028" main clearances. It should be nice and quiet with no cold piston rattle and great oil pressure hot and cold with 5 or 10W30 engine oil.

 

[Olds 307 and 403]

Talked to the machine shop again today, supposedly going to try to grind the crank this week. Katherine dropped off the pistons and rods on Thursday. She got there, the doors were locked. She saw an employee at the side door and gave him the parts. He said they were there, maybe up front. I said good, don't loose them, that is $1250 US in pistons and connecting rods. I mentioned again the pins need honed to fit. If they do these two things, only balancing left.