Restarting My '70 Nova Project

[racer86y]

Yes, I have had it out several times this winter. In fact, I took it for a 35 mile ride yesterday. Also drove it twice in December when we had warm says with no wet roads.
Going to have to get the garden hose out and give it a wash job to get rid of all the dust from sitting in the shop all winter.

Lucky you.I have to pull my motor out because of oil leak rear main on LS motor.

 

[Alan46]

Lucky you.I have to pull my motor out because of oil leak rear main on LS motor.

 

[dodge man]

Lucky you.I have to pull my motor out because of oil leak rear main on LS motor.

It’s been years ago I rolled in a new rear main seal on a big block Mopar with it in the car. I’m not 100% sure but I think I loosened all the main caps, stuck something in an oil hole in the crank like an Allen wrench, spun the crank and it forced the top half out and then rolled the new one in the same way. I’m not sure if that’s possible on other engines or not.

 

[racer86y]

It’s been years ago I rolled in a new rear main seal on a big block Mopar with it in the car. I’m not 100% sure but I think I loosened all the main caps, stuck something in an oil hole in the crank like an Allen wrench, spun the crank and it forced the top half out and then rolled the new one in the same way. I’m not sure if that’s possible on other engines or not.

Its not possible on one piece rear main seals.I have done a lot of Olds and sbc and bbc's that way.I wished i had not went with LS but its too late to turn back now.At 70 years old by myself pulling it and putting it back in by myself won't be easy.

 

[BravoXray]

Lucky you.I have to pull my motor out because of oil leak rear main on LS motor.

Not so lucky as you think.
Back somewhere in this thread are some posts about when I first got the Nova running, the rear main leaked badly. Pulled it out, replaced it, being very careful and sealing everything as specified, it still leaked. Pulled it again and replaced it. still leaked. Pulled it again, this time I talked to the tech that did the machine work on the block about not being able to keep it from leaking. He told me that on the 400 SBC blocks, it the are line bored, you have to use an oversize OD seal, a Felpro 2912 or something, because the OD seal bore is enlarged over the stock dimension. Replaced the seal again, and finally, no oil leak. Then a few months later, the block cracked through one of the block drain bosses up to a freeze plug boss. Pulled it again, the 4th time, and replaced the block with a Dart SHP block. So far, so good.

 

[BravoXray]

It’s been years ago I rolled in a new rear main seal on a big block Mopar with it in the car. I’m not 100% sure but I think I loosened all the main caps, stuck something in an oil hole in the crank like an Allen wrench, spun the crank and it forced the top half out and then rolled the new one in the same way. I’m not sure if that’s possible on other engines or not.

I did one in a 440 a few years ago in a friend's Charger. I was able to roll it in and also install the new seals on the sides of the rear main cap without dropping the other main caps. Still running with no leaks. I also dropped a couple rod caps, checked the bearings, and checked the torque on the other rods and main caps. The engine had been built by a backyard mechanic, and although they were all torqued to spec, we really didn't trust his work.
Trust, but verify.

 

[racer86y]

Not so lucky as you think.
Back somewhere in this thread are some posts about when I first got the Nova running, the rear main leaked badly. Pulled it out, replaced it, being very careful and sealing everything as specified, it still leaked. Pulled it again and replaced it. still leaked. Pulled it again, this time I talked to the tech that did the machine work on the block about not being able to keep it from leaking. He told me that on the 400 SBC blocks, it the are line bored, you have to use an oversize OD seal, a Felpro 2912 or something, because the OD seal bore is enlarged over the stock dimension. Replaced the seal again, and finally, no oil leak. Then a few months later, the block cracked through one of the block drain bosses up to a freeze plug boss. Pulled it again, the 4th time, and replaced the block with a Dart SHP block. So far, so good.

Dayummm,i hope you have good luck this round.If i have to pull this LS motor i am going to build my 400 sbc and its going in.

 

[arto98607]

I did 2-piece rear seal change on a 72 GMC pickup with Chev 350 way back around 1977 and it worked out very good.
Had no manuals, but spoke with a "Chevy guy" at work on how to do it.

Heck, I was in my early 20's and did not need any manuals back then!

No leaks, sold the truck 4 years later.

 

[BravoXray]

Dayummm,i hope you have good luck this round.If i have to pull this LS motor i am going to build my 400 sbc and its going in.

This is just my biased opinion, but the 400 blocks are one of the weakest SBC blocks. After reading a lot of posts on various Chevy forums, there seem to be, like it usually is with anything, those who love the SBC 400s or those that hate them.
I feel that they have a rather weak deck, evidenced here by the obvious signs that the cylinder walls were being distorted by the clamping force of the head studs, and losing seal near TDC. The block exhibited this around every head bolt hole. I never really ran this engine hard while it was being broken in, I ran it pretty easy, so that area was never exposed to a lot of stress or heat.

 

[Alan46]

This is just my biased opinion, but the 400 blocks are one of the weakest SBC blocks. After reading a lot of posts on various Chevy forums, there seem to be, like it usually is with anything, those who love the SBC 400s or those that hate them.
I feel that they have a rather weak deck, evidenced here by the obvious signs that the cylinder walls were being distorted by the clamping force of the head studs, and losing seal near TDC. The block exhibited this around every head bolt hole. I never really ran this engine hard while it was being broken in, I ran it pretty easy, so that area was never exposed to a lot of stress or heat.

View attachment 5307096

Wow!

 

[BravoXray]

Dayummm,i hope you have good luck this round.If i have to pull this LS motor i am going to build my 400 sbc and its going in.

Again, just my opinion, if you really want to build a SBC 400 based engine, buy one of the Dart SHP blocks. They are a far superior block and weigh 30 lbs more than a Chevy block. They also are machined to use Chevy roller cams and have an improved oiling system. Otherwise, I would stick with the LS engine.
World Products that makes a hybrid LS/SBC block that uses an SBC bottom end, but the deck is designed to bolt on LS heads. They are kind of spendy though, I think in the $4K area.

https://www.jegs.com/p/World-Produc...ybrid-Cast-Iron-Engine-Block/8153745/10002/-1

 

[racer86y]

I used to run 400 sbc's and never had much problem eith them at all.They did not run hot and lasted several years before refreshing it just because.

 

[BravoXray]

It was a nice warm day here in northern Indiana, so I took a friend's SIL and grandchildren for a ride in the Nova. Tom, the other adult, was impressed how well the Nova rides, and the power of the 434 under the hood.

 

[racer86y]

Nice ride!! Have fun

 

[MossRoad]

It was a nice warm day here in northern Indiana, so I took a friend's SIL and grandchildren for a ride in the Nova. Tom, the other adult, was impressed how well the Nova rides, and the power of the 434 under the hood.

Nice! Kid in the back has the same expression my brain has every time I stomp an accelerator!