Technical 400 sbc

I have a chance to pick up a 400 sbc short block that is bored .060 the engine ran about 10.000 miles when the starter gave up. In changing the starter they messed up the outboard starter hole in the block. I was thinking early bellhouseing mount starter. Question would you trust a .060 over 400. It is $100

 

For a $100 its worth a gamble. Yep bell housing starter. There is a Guy on U Tube Jonathan W. He dis a video of a automace equipped small block that had the same starter issues. He bought a spacer adapter that bolted between the engine and trans and mounted a bell housing starter.

 

Drill it out and put in a Helicoil.

 

Normally...a .060" over 400 Chevy is a recipe for over heating problems.
I'd say...no, to much work and money to take that chance. Find another.

Mike

 

Heli coil it...

I wouldnt run a 400 SBC myself..

Hard to keep them cool in AZ.

 

I always was told the same .060 over there done.

But yet I have seen .080 over slugs for sale

 

The whole out side of the bolt hole is gone

 

I welded up a broken bolt hole like that with nickel rod, and re drilled and tapped the hole on a circle track motor. Worked fine till it pitched a rod.

 

For a $100, I'd trust it. You know it already ran; maybe they can tell you what temperatures it saw.

As far as the broken starter bolt boss, it can be welded, and repaired. We cut the ear off of an exhaust manifold flange once, and used it to replace broken motor mount boss on a Dodge 340 engine. You'll have the engine available to work upside down, in shop, so I'd look at getting it back to original starter mount.

 

if its going into a stick shift vehicle a stick starter mount bellhousing is easy to find.

 

If it is the early block I might take a chance, might, if it were free, but I don't know if I would pay 100.00 for it. Any inspection paper for it? The good blocks that I like have "509" cast into the pan rail.

 

heck I sell the 400 cranks and rods to those idiots who build 383's for a $100.

 

As Algoma56 said, 'work on it upside down, in a shop'. Yes, and a mill will oversize that worn hole, centering it up. Then use a threaded BUSHING (1/2" USS thread outside, 3/8" USS inside. Blue locktite bushing in block. Done.
I assembled a .060" over 400 small block in my shop, (1983) the owner is still driving the F100 it's in. DAILY.

 

I wouldn't be afraid of it, just be fastidious about cooling system maintenance (flush and change twice a year, use distilled water, and good antifreeze or corrosion inhibitor). Gotta keep those steam holes open or it WILL overheat! Also, unless you go to a mini starter, don't forget the support bracket from the starter to the block by the motor mount. It's deletion is probably why the chunk is missing out of the block now. ;-)

Sent from my SM-G955F using The H.A.M.B. mobile app

 

Bought it I figured the crank is worth that much.

 

400's are externally balanced. The damper and flywheel must be for that application. The heads need the matching steam holes. I think the oil pump rod between it and the distributor is also different. It has its diameter turned down in a couple places for clearance. Good luck with the motor

 

all that effort for a boiler.

 

I ran my 400 daily for 17 years. It never ran hot and there was 7 inches from the fan to the radiator. No shroud

 

Fix it , and run it [ Cubes is a good thing you know!]

Or use Tri-5 style [or truck]bellhousingswith the starter
They use the larger 168 tooth flywheel ,the same as a 400 but you'll need the external balanced flywheel.

400's don't overheat in dirt car racing!

 

Off the shelf CP pistons for dirt track stop at 4.185 and really don't like hi-comp ones over 4.165. Dart blocks are much the same. I'd run it with a 350 crank (3.480") a better combo than the other way. It's good to flow water out of the rear of the heads at the intake upto the thermostat housing.

 

I'll most likely go this route I've used them on 383s https://images.search.yahoo.com/search/images;_ylt=AwrJ6SWnOFdd3OMAPXtXNyoA;_ylu=X3oDMTEyamZhMGRqBGNvbG8DYmYxBHBvcwMxBHZ0aWQDQTA1OTlfMQRzZWMDc2M-?p=speedway+400+balance+plates&fr=yfp-t-s&guccounter=1&guce_referrer=aHR0cHM6Ly9zZWFyY2gueWFob28uY29tL3NlYXJjaD9wPXNwZWVkd2F5KzQwMCtiYWxhbmNlK3BsYXRlcyZmcj15ZnAtdC1zJmZwPTEmdG9nZ2xlPTEmY29wPW1zcyZlaT1VVEYtOA&guce_referrer_sig=AQAAAAu_L52jWLRrVtQoxj6XHa2AVzY2vF-VNWRI907UxpLD9hOEXNZO0fJpBsYmX23AiVZFGMBJDPRRSgi0mxEfJsct7bUqMWKC_okut2SggnBdQ5mwpJe_5jHbeNS3sVE0BROxL-gsEocySKefE6xQSvJhEifvIP8UeQsDI4QOwwup#id=0&iurl=https://content.speedwaymotors.com/ProductImages/425RM521_L_04236a56-cf90-48a3-8487-4ccea8ff0e70.jpg&action=click

 

A boiler? I rebuilt a 400 for my 120,000 mile ‘82 2WD Blazer. The radiator was the original one and I used the Q-jet and manifold and all the other ancillaries (except for a new water pump) from the original 305 the truck came with. It ran strong and never hot, I don’t understand all the comments. With a well serviced cooling system and a correctly tuned engine why would it be a boiler? I have no doubt thousands were sold in Massachusetts (and Arizona too!) and they ran no different than any other SBC.
Hey @sunbeam, you’ll have no problem being in Kansas, you can drive that thing on The Yellow Brick Road in the summer all you want.

 

400 bored .040 is a 408. Ran damn good in a '57 Chevrolet. Cost a bunch more than 100 bucks then.

 

You can always sleeve it and bore it to your standards.

 

They will overheat if you work them as a truck motor. I've had 2, both standard bore, one was new crate motor when GM Parts Div were dumping these dirt cheap to GM dealers in the early 80s.
Both were run is several 4wd pickups hauling a slide-in camper. They ran way hot when pulling the nasty grinding hill in eastern Pennsylvania on the yearly trek to Hershey in Oct temps. I'd watch the gauge noticeably climb each year on that one particular hill. Did not boil, but certainly gets your attention.

Worst issue was deep sand on ocean beach camping. Both of these would barely make it to the camping lot 1.5 miles out in deep sand.. Shut the motor off and wait a few moments and they both puked each trip out in normal summer temps. The 350s I ran out there, never boiled.

This is no BS.

Think what you want, but to advise that he won't have ANY issues in Kansas w/60 over, despite not knowing how he will use it, is ludicrous.

.

 

I have had two different LUV'S with 400's in them, neither ran hot and one had a/c. Both had flathead Fodr 6 radiators and neither had an E-brake (no room). A 400 is an interesting engine in that with the bed loaded and pulling a loaded trailer uphill into the wind it got 12mpg. Truck empty and going downhill with the wind---12mpg.

 

I have 400 blocks in 3 of my cars , including my daily driver . Not a single one runs hot. But all of them are .030 over , I might go to .040 if it was sonic checked , but never .060...

 

Mimilan tells us:

"400's don't overheat in dirt car racing!"

I learned that the dirt track guys are a good source of 400 info. Last fall there was a thread titled:

BEST HEADS FOR A SBC 400

There was interesting topic drift that gave a good variety of 400 stories. I posted the following in that thread:

I'm not an engine guy but it's time for my 400 story. Streetrod. Never raced. Ran my 400 for 10 years as pulled. After rebuild, incl mild cam, started getting antifreeze in no. 1 cylinder. Learned from oval track guys that they all run 400 engines to be at top of class. They told us that decking the block during rebuilt weakens the deck in the crotch between nos. 1 & 3 where a steam hole and head bolt are close together. Torquing the head bold distorts the deck enough for my leak. They told us they always plug steam holes when building a 400. Not needed. They said there is a crate engine available with siamese cylinders and no steam holes. Don't remember which it is. I took their advice, plugged all steam holes. Never a problem. Never see 200 degrees in very mild street driving. No racing.

(Rebuild was .030 over. This experience was over 5 years ago. My driving is now all in FL and A/C is usually on. And no shroud!)

 

Running a 400 with Vortec heads in my 32 3 window. Used to run a little warm until a mechanic figured out it had a reverse rotation water pump on it. I bought the car done. It was built in early 2000’s. Pump painted same color as block so assume it was original. Runs nice and cool with a correctly rotating pump.


Sent from my iPad using The H.A.M.B. mobile app