340 getting close

340/4
30 over
Crower cam stage 2
High flow oil pump
5/8” oil pick up

other than that pretty stock


Gonna spin it today and see the oil flow! been working on it for a while! Praying it runs good!

 

Keep us posted!

 

Oil is moving! But I’m getting hardly any on the right (passenger) rockers and a ton on the left.????

 

The left (drivers side) oil galley feeds ONLY those lifters.
The right (passenger side) galley feeds both lifters AND main and rod bearings.
I wouldn’t worry about it.
That right oil galley is fed directly off the pump outlet, so if you see oil on the drivers side, it’s definitely getting oil on the passenger side as the drivers side has a much more convoluted path to receive oil.

 

Ok, Im going with your advice and pushing forward, gonna drop that thing into the Blue dragon soon! Thanks for your insight.

 

Installed the 340-4 a few days ago, it went pretty well. Fired right up and I broke in the cam to the best of my abilities. It drives pretty good. I just need to adjust the carb a bit. And keep going with the project.

 

Excellent!
My 340 is on the stand. Has a lot of goodies but it's waiting right now for the intake to be skimmed and then cerokoted. I'll give a quick rundown for whoever is curious:

Rod and main bearing clearances set in the .0008-.0012 range (I forget the exact number it measured out to)
Scat 7" rods, milled for cam lobe clearance and notched for oil squirt (about 660 g)
Venolia pistons w/ 70 gram pins (around 550g total with rings)
Balanced to 8k
O-ringed deck
1/4" main cap stabilizer plate
Oil pump deburred, ported and optimized, suction side enlarged (end clearance less than .001")
Roller solid lifter cam similar to TA212 specs
Cam retention plate
Standard composition head gaskets
late 10 bolt Rover 4.0/4.6L aluminum heads with 350lb Beehive springs
Procomp adjustable rockers bored to fit stock rockershafts
SBC solid roller lifters with oiling slot ground in body
Custom valley pan and intake hand built for Eaton M112 blower
Rover cast valve covers with 1/2" spacer
Custom made 8 rib accessory drive
Custom oil pump drive / cam position sensor
Custom crank position sensor
COP ignition
Port injection using the GM '411 (P-02) ECM, modified Camaro tune and 35lb injectors
Ford Lightning Eaton M-112 blower w/5lb of boost
Enderlie style hand built Bug Catcher/air cleaner/Throttle body assembly

This is the spare engine for my 2700lb MGB roadster. Right now it has a slightly improved iron head 2bbl Buick 300 in it which I refer to as my Mule. This winter/spring I expect to be able to swap in the stroker 300 I've been building. Similar specs to the 340 in a shorter block and a few small improvements plus a set of TA/Rover heads with titanium valves, beehive springs and TA's stud mount roller rockers. Also new repop MGB V8 valve covers. With a little luck I'll never need the 340.
Jim

 

In your opinion is the stock 340 block stronger than the 300 block?

 

I don't think so, in fact in theory you might even be able to claim it isn't as strong but in reality I don't think there is any difference. The difference in weight is about 2 pounds. That is accounted for in the different block height.

Jim

 

Maybe they didn't see any need to make the blocks stronger since the crankshaft is bigger.

 

Don't know. There is no significant difference in the weight of the cranks either which is a little odd considering the 1/2" difference in main journal diameter.

Jim

 

I believe the deep skirt block design is leftover from the days of cast iron transmissions and the extra weight/pressure they applied to the block. I don't think the skirting adds much strength at all to the reciprocating aspect of the block. I have my 340 on the stand right now, and I don't think the skirting is even 1/4" thick..

 

It's all thinwall casting, Buick really was a pioneer in that technology and the high nickel content added a lot of strength. Very different material from what Chevy and others were using. The deep skirt does add rigidity to the block and helps to suppress harmonic vibrations. It seems that a broken crank was an extremely rare occurrence with these engines. Anyone here know personally about an example? I don't.

 

I believe Foxes Den broke his 350 crank many years ago.
But yes, the deep skirted block is substantially stronger than the 455 non skirted block.
I have a book (an old one) that goes into engine design and mentions the Buick 350 is the only manufacturer (GM) that is still casting deep skirted blocks that is tied to diesel engine technology ( This was in the early/mid 70’s)