Rebuilding 350 - I'm in a pinch
#1
Rebuilding 350 - I'm in a pinch
'72 block, Engine was rebuilt a years ago, briefly ran than pulled from car so he could install on air motor but he died before he could do it. A couple years later he sons sold it and then I picked it up. The engine was really clean and no wear marks on the bearings or cylinder but I decide to rebuild again before I put it in my car. I went off of the bearings that were installed previously when I ordered new bearings but when I installed the rods, the crank got tighter and harder to turn. I gapped all the rings and those clearances are good. Plasi gauge had my rod bearings at 0.0015. Is that to tight?
The rod bearing size is .030
The rod bearing size is .030
#9
I just measured and front deck to top of piston is coming up .055
Piston dish depth .077 by roughly 2.54. I hope to be okay on cr.
Last edited by Joe King; February 21st, 2018 at 11:22 AM.
#10
I get 8.7 to 1 with 68cc heads and the Felpro gasket, .040" thick with a 4.230" gasket bore. Those should be the 6cc dish pistons.
https://www.uempistons.com/index.php...413bddeb82813f
https://www.uempistons.com/index.php...413bddeb82813f
#11
Yep, .077" deep dish is the 6cc version. They are what I have in my engine from the rebuild back in 1982.
The factory 6cc dish pistons were used in the 10.25:1 advertised compression ratio engines, but you see the above calculations using actual measurements that the final CR isn't anywhere near 10.25:1 - you would need to do some machining to either the heads or the block deck to bring it up with those short pistons.
The factory 6cc dish pistons were used in the 10.25:1 advertised compression ratio engines, but you see the above calculations using actual measurements that the final CR isn't anywhere near 10.25:1 - you would need to do some machining to either the heads or the block deck to bring it up with those short pistons.
#13
#14
She is already put together, I'm putting the motor in a heavy Cadillac so she's not going to be a race car but HAS to be better than that tired ole 307 that is in it. I just have a few things to work out before i yank the old and drop in the new. Mostly figuring out what I need to keep to keep the ccc happy. I like my A/C, tcc and cruise control... losing ccc not really an option for me
I think Moroso should give their stickers with their name cut out, I love the look of the gold shooting out at you!
I think Moroso should give their stickers with their name cut out, I love the look of the gold shooting out at you!
#16
She is already put together, I'm putting the motor in a heavy Cadillac so she's not going to be a race car but HAS to be better than that tired ole 307 that is in it. I just have a few things to work out before i yank the old and drop in the new. Mostly figuring out what I need to keep to keep the ccc happy. I like my A/C, tcc and cruise control... losing ccc not really an option for me ��
I think Moroso should give their stickers with their name cut out, I love the look of the gold shooting out at you!
I think Moroso should give their stickers with their name cut out, I love the look of the gold shooting out at you!
#17
What cam? With unmilled #8 heads, which I have CC'd at 77 to 78 CC, that puts you right at 8 to 1. That oil pan is completely unnecessary with that mild build in a car that won't see high RPM. But it does look good.
#18
Cutlassefi, Central Florida- I live in Deltona, South of Daytona and North of Orlando
#19
Oh yeah, they were 73cc correct? That puts you around 8.3 to 1. That cam had 140 to 142 cranking psi with it 2 degrees advanced in my stock 76 350 which was around 7.8 or 7.9 to 1 stock. It should play well with even the 85 and up swirl port aggressive timing curve. I would run a G hanger and a CK or CV secondary rods to start in your Qjet.
#20
I probably can't blame the q-jet entirely, it is a tired 307 with 130k pushing around a big ole Cadillac Brougham.
Thanks again, this was literally one of the last things I was trying to work out.
#25
#26
It had a brand new one on it and I sold it for super cheap, well maybe not super cheap but at the time I sold it I had no idea what it was worth. It sold on craigslist within 2 hours. That should have been my sign that it was to cheap.
#27
Let's talk knock sensor for a minute. I pulled it out of my 307 and at the same location on the 350 the port is a water drain but closed off completely on the 307. Is it okay to screw in the same location as the water port or is there a better suited place for it?
#28
Yes, that is what I did when I installed the knock sensor when I put an Olds 350 in my 94 Z71 running the factory TBI. Make sure you torque the sensor to the recommended value, the TBI was 11 ft/lbs.
#30
Now that must be a sweet swap! Totally jealous over here. I did try to screw it in but it seemed liked the FAT part of the sensor scrapped the block before it was tight so I am having to rethink this... Maybe I will try again tomorrow.
#31
It was a sweet set up till it burnt to the ground, the circulating block heater shorted out. I think it was directly in the block, you could add a short piece of pipe and adapter but I guess that defeats the purpose. Post a pic of the sensor.
#37
Oil Stuff
I have been doing a bunch of research and I think I hit a fork in the road. I have this 7quart oil pan and a lot of people like these so they can run 5 quarts of oil and keep the windage down. I liked that idea, I was about to go custom make a dipstick for this bad boy so it would really fill work 5 quarts (minus filter) but then I read that with a high volume oil pump, it is better to run 7 quarts because it can run dry? So I'm kind of stumped here. I finally dropped the motor in the car yesterday and my hope is to finish everything up and **** the neighbors of tomorrow for my break in start up. Can't take her for exhaust until she is running so possibly running straight headers unless I can squeeze a little room of the collector to Temp mount a muffler there but it is pretty tight.
#38
I believe 6 quarts plus filter is the right amount to run in that pan. In your car, it will probably help extend oil changes slightly, unless you push high rpm, you will see no benefit. Part of the reason oil changes can be extended so much is because new cars use synthetic and hold 9 quarts! Add in much tighter and more consistent tolerances along with direct injection, super fast EFI, our old junk can't compete.
#39
Vacuum Hoses
So now I am onto the vacuum lines and I am deleting a bunch but not all. I do want to keep the prefer valve that goes to the canister. In keeping that, do I have to keep the ccv octopus thing also? I would rather delete it if it wouldn't hurt anything.
Edit: I just kept this thing. It looks like it there is a breather on the top of carb that should be hooked up and connects to it.
Edit: I just kept this thing. It looks like it there is a breather on the top of carb that should be hooked up and connects to it.
Last edited by Joe King; March 26th, 2018 at 07:26 AM.
#40
I have had trouble with this engine ever since I did my initial start up. Finally figured out the #8 heads that have had a ton of work to them had... Well, to much work to them. Valve seats were cut so far that the valve attends we're sticking out to day and someone actually cut them shorter just so the rockets would some what work but in 2 cylinders the valves didn't seal.
Needless to say I finally picked up a set of 7A heads that are bolt on ready and I am excited! The old heads had dual springs but the new one's have the own single springs which I think are better for my Camshaft anyways. So I guess I will pick up my old heads and pull the springs of and scrap the rest of them, I can't see putting another $600 in them just to get them back in shape. I'm still taking the new one's in to be double checked that they are ready to go.
On another note, I mic'd my fel-pro head gasket and it measured .045, I thought it got a little thinner than that. Maybe when installed it shrinks a little bit.
Needless to say I finally picked up a set of 7A heads that are bolt on ready and I am excited! The old heads had dual springs but the new one's have the own single springs which I think are better for my Camshaft anyways. So I guess I will pick up my old heads and pull the springs of and scrap the rest of them, I can't see putting another $600 in them just to get them back in shape. I'm still taking the new one's in to be double checked that they are ready to go.
On another note, I mic'd my fel-pro head gasket and it measured .045, I thought it got a little thinner than that. Maybe when installed it shrinks a little bit.