Engine block search

[tscott9330]

Alright, I am looking for a 400 ci block, and it looks like the cheapest way is to do is to go junk yard diving. So my question is this, what vehicles came with the 400 block?

Also, I saw a product on tv one time that was used to tell wheather an engine block was cracked or not. It consisted of a system of pastes that you rubbed on the block and then wiped off then when you added a developer that then showed any cracks where you applied the pastes. Does anyone know what this stuf is called?

Tom

 

[Dave L.]

The 400 chevy small blocks were used in light duty trucks from 75-79. They were used very sparingly in 70-71 passenger cars also. They are getting pretty tough to find in the bone yards.


Dave

 

[AKRAY4PLAY]

Tom,
i would look at K5 Blazers from '73-'78, Oldsmobile and Pontiac grocery getters, light duty commercial trucks (2 ton) are the best bet and old Cop cars (mainly Caprices). GM made a bunch of 400's, but they have been snapped up and destroyed in the pursuit of power. STAY AWAY FROM FACTORY 4-BOLT MAINS!!! magnafluxing and/or sonic checking is the best thing for detecting cracks. also look for core shift. you may be able to find a 400 at some lower-end machine shops. if you are planning on splayed mains, your best bet may be a new GM 400 block. check pricing on all machine work, sonic checking, shot peening and splayed mains. SONIC CHECKS ARE GREAT INSURANCE, some 400's had thin castings around the cylinder bore and sonic checking is the only way of measuring wall thickness accurately. steam holes in the cylinder deck are a must, '71-'72 blocks did not have the holes and should be considdered compromised. they most likely have been subjected to localized overheating between the cylinders resulting in a weaker block not suitable for building right. lastly, don't get a block that needs more than .030" overbore to be servicable. you can go more than .030" but it is risky. i have some more info on 400's, and i will gladly try and answer any othger questions you may have. Brian

 

[tscott9330]

you mentioned getting a new 400 block from GM. where would I find one of those and how much is the difference in price of a new block than a fully prepped salvage yard block?

Tom

 

[Dave L.]

Trust me on this one.. You will not find any short block,bare block anything block 400 still available through GM. Olds and Pontiacs did not use Chevy 400 small blocks. The ONLY vehicles which used the 400 small block are the ones in my previous post.
Good luck in your search.

Dave

 

[AKRAY4PLAY]

Dave,
i beg to differ with you on this one! i found my 400 in an Oldsmobile. as for new blocks, check this out. it is available from GM performance and is a 400 with built-in needed improvements.
http://www.paceparts.com/product.asp?0=243&1=245&3=1166
GM is making a couple of different versions of the "Rocket Block" for different uses. you can get it in tall deck, regular deck, all aluminum, dry sump and/or wet sump to fit your needs.

Tom,
depending on what you want to build will determine the over-all machining costs. a relatively mild motor will not require the prep work and precision maching of a full competition engine. for instance, you don't need splayed mains for a 450hp motor turning 5500rpm. this alone will save about $600 on machine and parts costs. bottom line, you are looking at $1300 to mild build and around $2400 to full race build. these prices are Alaskan, so they most likely will be different for you, that is why i say it is best to check with local machine shops.
if you are looking for the best and possible upgrades in the future, then the new GM rocket block is your only real choice. machine costs vs. purchase price is a wash, and the new block has all the right goodies needed to go insanely fast. not to mention, you can make a 454 small block out of the new platform!!!! Brian

 

[AKRAY4PLAY]

here are a couple of other options with descriptions.
http://www.paceparts.com/product.asp?0=243&1=245&3=883
http://www.paceparts.com/product.asp?0=243&1=245&3=1167
http://www.paceparts.com/product.asp?0=243&1=245&3=302
Happy viewing!!!

 

[Dave L.]

Brian- I stand corrected on the availability from GM for a bare block,you are correct on that part number,however a 400 Chevy small block was NEVER installed in a Buick-Olds-Pontiac. If you got one out of an Olds,somebody installed it in that car. Check with any GM dealer and they will verify this.

Dave

 

[tscott9330]

I think these blocks are a bit to pricey for my tastes. I am not going to build an all out race motor, I just want 400+ hp. I don't need a block that will let me spin to 7000 rpm, I don't think this block will ever see any more than 6000 rpm and that would be an extreme case. Most of my power will be made in a daily driver friendly range.

I think i'll stick with the junkyard block. I know the reasoning behind people not wanting to use a 4 bolt main 400, but I asked some of the guys at the local speed shop and they said it was basicaly a debatable subject.

However i think I will be fine with either a 2 or 4 bolt main. What everone think?

Also are there any internet sources for block codes so I can tell what block it is from the casting number?

Tom

 

[AKRAY4PLAY]

Tom,
for 400hp, you will not need splayed mains. just some ARP studs will work nicely. i would suggest running longer rods though. the stock 400 rods are very short and add a lot of side loading to the cylinder walls. 5.7 rods are easily found (they're stock 350 rods), but you will get better eff. #'s with 6.0 rods. it is a trade off, the 6.0's are more expensive because of the specialty pistons. it is about $300 more to build a 6.0" rod 400. heads will make the world, it is better to put your money there. here is a site that will get you started on the quest for a block.
http://www.geocities.com/meanracing/BlockCastingInformation.html
GM does make a "stock" 400 block, i think it runs about $1850. so if your set on a 400 and can't find a block, that is another option.
with your power goals, have you considdered a 383?? it will be far less hassle and maybe a couple hundred less to build. just another idea. Brian

 

[tscott9330]

well, I was building a 383 but I kind of got screwed out of $1100 worth of parts.(long Story)

So I decided that since I now have to buy a block I might as well get the most cubes for the dollar and I don't think I can afford a big block just yet and I think the extra weight would counter any extra power I might get. So the next logical choice is a 400 base build. I already have the internals I want in mind. I agree with your choice of the 6 inch rods. I am going to try a little experiment, I plan on buying as many of the parts as possible off of ebay. I believe I have done enough research that I can cut my costs considerably with a few good deals on ebay. I am going to build with as many forged parts as i can find (i.e. crank, rods, and pistons) I am doing this so that in the future I may want to put a little nitrous to it. No more than a 150 shot though and it would be used only on rare occasions. More for show than go really.



Tom

 

[Robin7TFour]

Tom, i would be happy to help you in any way you need. i live cross-town from you. feel free to e-mail me and we can swap numbers.



robin

 

[tscott9330]

Sounds good, I'll keep you posted Robin.

Tom

 

[AKRAY4PLAY]

Tom,
i would not skimp on pistons and rings with nitrious. it only takes one shot to smoke a top end. there are great deals on Ebay, more power to you if you can save money. heads are another area to focus. unless set up perfectly, nitrious adds a lot of heat and pressure. this is were valves, seats and deck thickness come into play. most of the lower end aluminum heads don't hold up for the long haul under these conditions, so beware. if there is anything else i can help with, don't hessitate to ask. Brian

 

[Gunther]

Hello

Tom, this stuff for the crack checks you talked about is DYE PENETRANT. This is available in 2 different kinds.
Once it's a liquid that is brushed onto the surface and after a while washed off. A black light will show all cracks afterwards as the liquid will have entered even the finest cracks.
The other stuff is in spray bottles, also some DYE ( red coloured ), some kind of red oil, again this is washed off after a while and than a white powder ( like baby powder ) is sprayed over the area. If there is a crack, the red oily liquid will show up in the white powdery spray.
Both this methods will only show surface cracks.

Good luck. Gunther