how many people are using a 2pc rear main seal block even though they are not legal to have in our cars cause of emmision?
I am seriously considering buying an aluminum 400 small block. thanks

 

who said they are not legal?? all pre 86 has 2PC crank.
there is no aluminum 400s from the factory unless if you are talking about after market.

 

yea i am talking about motown, dart, or donovan but i am not too sure now cause it is for daily diver will the aluminum warp?

 

This is the first time I've heard that a block with a two-piece seal violates emissions laws. Since my 1985 has a two-piece rear main seal, I guess I've got a problem.

 

Considering his car is a 1990 and the one-piece RMS replaced the two-piece RMS back in 1987, that would be a good indicator that he is using an older block than his vehicle's model year ... which is not emission's compliant. You can only replace your engine with the same year as your car or newer. But who checks for that?

As for using an aluminum block for the street ... LS1s are aluminum blocks. So long as your cooling system is functioning properly, you should not have a problem. But why the 'exotic' block?

 

Technically a two piece seal would be illegal for anything newer than 1987, but sfter the torque converter, or flywheel and clutch is installed, who can see what seal you have in there. If you are interrested in the Motown aluminum block, you won't have to worry about it warping. Pick up the April 2005 issue of Super Chevy, if you don't have it already. On page 65 is an article about the aluminum 454 small block crate motor from World Products. Take a look at the pics. World put reinforcing ribs all over that block.

 

Not if you read the post again and see it says '87 and later

 

well does anyone know what block to use because what are my chances of actually having the inspector see it is a 2piece rear main seal, and u are saying it will be ok on a daily driver.

 

meaning dart, donovan, or motown

 

So if your 1 peice rear seal block cracks, you goto a junk yard and get a 2 peice, then transfer everything over from the orig block to the junk yard block, it wont be emissions legal?

 

It is not that easy. Technically you won't be smog legal, but who is ever going to see the rear main seal once the engine is installed and hooked up to the trans? You can't just transfer the parts over, however. If you have a one piece rear main seal, you probably have factory roller lifters. The junk yard motor you find with a two piece rear main won't have any provision for factory roller lifters, so you loose your roller cam. You can put in aftermarket rollers, but it will cost you $$$.

 

I just went through the dmv, air resources board and epa sites to find where it says you can't change a block.

Somebody please identify and quote the exact source for the claim that you can't change an engine block to a one-piece seal and be smog legal.

Edit. Here's something I found from smogcheck.ca.gov:

Visual Inspection: The first of the three vital parts of the California Smog Check. The visual inspection checks for missing, disconnected, or visibly damaged emissions-system components, including the catalytic converter, the thermostatic air cleaner, the heat riser and the smog pump. Emissions system defects identified during the visual inspection are considered unhealthy for the air and result in an overall Smog Check failure.

 

You can change from a two piece seal block to a one piece without any problem because you can always go with a later model engine in an earlier car as long as you have the newer smog stuff. You are not supposed to put an engine in a car that is older than the year model of the car. Since the two piece seal block is for 87 and older, you technically can't use one in a 88 or newer car. You won't find blocks listed on the dmv site, but you will find engines listed.

 

Agreed, but are "block" and "engine" defined as the same thing?

And, note that the visual inspection does not cover "rear main seal."

 

You can pass smog with a 2 piece seal block as long as the dip stick oil tube is on the passenger side of the car. They can't see the cam nor the rear main seal with the trans bolted up to it. Hell, some people are passing smog with a 400 block with the oil tube on the driverside of the engine. Just have all of the emissions hook up.

 

Here is a link with a little bit more info:

http://www.smogcheck.ca.gov/StdPage....s-Jan_1994.htm

When they talk about an "engine change," they are referring to changing a TBI to an LT1 or a carb to an LS1, that type of change. Not "pulling out a 305 and putting in a 350" type of change.

They dont specifically say you cannot use an older part in a newer engine, but they do say you must make sure the system as a whole is the same as or newer than the car.