Thread: 400 engine combo what will it do?

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hi tony you might try going to a local air port and talk to some of the independent small repair shops ask them if can bring the motor there in the back of a p/u and look in the spark plug hole with there borascope the all should have them I have one I could loan you but shipping back an forth would be way too much just offer them a 12 pack or in your case a couple of pints they will probly be happy to help you worth a try ......ted

Ted has a good idea. A stock type 400 piston should have a dished topand 4 valve reliefs and look something like the attached photo.

Lynn, thanks for posting that photo. If you're concerned with creating an excellent squish in the motor, this is the type of piston you DO NOT want to use. The only squish that is generated with the piston in the photo is by the thin ring around the perimeter of the piston. Here's a photo of a true flat-top with valve reliefs....
http://kb-silvolite.com/performance....tails&P_id=212
You can see that there is a very large flat area on the piston crown to mate up with the flat underside of the head and "squish" the mixture out of the area and over toward the spark plug for a detonation-resistant arrangement.

Here's a photo of a 30cc D-cup Keith Black piston showing the large flat area on the right of the photo to generate squish....
http://kb-silvolite.com/performance....tails&P_id=209

I see it all the time on these forums. Fellows spend a fortune on heads, cam, lifters, carbs, roller rockers, headers and intake manifolds, but fail to put the proper pistons in the motor. If you use pistons that will generate good squish and a cam with an intake valve closing point that is mated properly to the static compression ratio, you're going to be rewarded with a good-running motor that will operate on pump gas with full ignition timing.

Hi Tony,
No, you can't remove the pistons from the bottem of the motor. Not possible. The webbing in the block will prevent that. Easy to see: the pistons are only about a 1/2 of an inch apart, but the main caps are almost an inch wide. The only way to be sure is to take off the heads. That's no big deal. Disassembly and reassembly can be done in a day with measuring all the stuff said here on CHR.
For a street car a 3000 stall is too high, optimum would be more like a 2200 if you want it sporty. Depends on bottom end torque. Circle track engines are made to work only within a narrow powerband, mostly just 1000rpms or so wide. I've never done it, but building a circle track motor is physically easier than building a street engine with a broad power band (like Tech, I love numbers )
With a 400 block and stock bottom end, I would be careful when using the 500 horses you can get out of it. You'll only get those numbers at high RPMs, and it's RPMs that will kill stock bottom ends. I would go for something more in the torque range and a lower stall. Also makes for better mileage (in case you care). The parts you have are high quality, you should be able to get them sold on Ebay easily. Then it won't be too expensive to get parts you'll be happy with. I don't only like numbers, I'm also a great fan of books. That's where you get a lot of good information. No one on CHR will tell you all the tips and tricks about engine building, it's so complicated you'll need more general knowledge about it before you start. I don't want to be rude, but you sound like a newbie to engine building. That's fine, I'm a newbie, too Just remember: parts brake more quickly than you think, especially if you install things incorrectly (ask me ), so take your time and build an engine that fits your needs and lasts.
Wish you good luck and fun,
Max

hi guys many thanks for all the info tried getting a borascope but to no avail.
have spoke more with previous owner and have decided to bite the bullet and fit as is,it may not be optimum set up for my use but its got to move my car better than a standard 180 horse olds ill report back my findings but it will probably be a month or two as im rebuilding ,cleaning restoring the whole front end as well
cheers