Alright, well I just graduated high school and it's starting to look like I'll finally get a job this summer as a golf cart mechanic . And that jazz combo I'm in should be getting gigs as soon as our bass player gets back in town.

Since I'll be making some money I'd like to build up an engine for the Camaro and replace the 305 (it's seen better days). I've been looking for a 400 small block and found this on Summit:
http://store.summitracing.com/partde...0&autoview=sku

Now I really need to make up for having that 305. So a 427 is sounding pretty nice. I ran a search and found that there may be some clearance issues with the long stroke. Can anyone go more in depth with that?

And finally, does anyone know some casting numbers for the 400s so I can make sure I'm getting what I pay for.

Thanks a lot guys.

P.S. One more question: How much power can the body stand with some Spohn subframe connectors and maybe a strut tower brace? It's a hard top. Thanks again.

 

Your best bet would be to spend another $1900 on a Motown block.

 

You can find a list of 400 SBC block casting numbers at MorTec, Inc. Home Page.

400 SBC where installed in full size chevs, some trucks and vans, Monte carlos
El caminos, chevelles from 1970 to about 1976 for passenger cars and up to 1980 for trucks. 400sbcs can be identified by the flywheel and balancer (has a balance weight) by the block, a bulge near the motor mount pad on the side of the block, has a 4.125" cylinder bore. Has extra "steam holes" drilled in the decks and on the factory cylinder heads.

All the factory 400's came with lame low performance cylinder heads. Plan on getting some aftermarket heads if you plan on going fast. Replacing the short 5.565" conecting rods with 5.7" rods is recomended. Enlist the help of a qualified automotive machinist, as there are a few clearance issues that need to be delt with when modifying a 400 SBC for high performance use.

 

That's a great idea. Except for the part where I have to spend another $1,900.

I figured that I would need new heads to replace the old smoggers. And there are plenty of other threads that I can get good engine combos from.

But what exactly would need to be done to the block/oil pan to allow for the longer stroke?

 

A 427 with a stock block is really pushing it on a stock 400 block, oil pan is no big deal just beat a stock steel pan w/ a hammer until it fits. You'll probably be into the water jacket with anything more than a 3.875 stroke. Look for a two bolt main block, they have higher nickel content and are stronger than the four bolt main blocks when installing splayed aftermarket billet main caps. Also you should look for something with a stock bore or close too it, otherwise you'll be looking at custom pistons and big bucks. You could make a 426 with off the shelf pistons, 3.875 stroke crank, and 6" rods bored .040, just hope you never have to install a larger set of pistons.. The stock blocks have been made into 454c.i.'s with block filler and modified bbc rods, so it is possible to use the stock blocks just how much ahead you are vs. buying a world or dart block is iffy plus the aftermarket block has better oil routing and stronger bearing support, thicker cylinder walls, etc.

Edit- block mods are the same for a stroked 383 as they are for a stroked 400. You'll need to probably run a small base circle cam and also check the cam clearance, not just the crank to block clearance. They can be built on a budget, I just think that a 427 would be really hard to find parts for on a budget. A 406 or 420 might be better since the parts are a lot more common.

 

True. A 406 is really more than enough to make me happy. I just thought it would be more fun to say it was a 427.

But do you think that the Camaro hard top body could handle 450-500hp with Spohn sub-frame connectors? I don't want to build a bitchin' engine just to have it twist the car to hell.

 

I agree, using a real Chevy block is the most cost effective way to go. Try to find a block with 2-bolt mains as these are stronger than the 4-bolt factory blocks (the outboard bolt holes give the block a very easy place to crack!). You can use aftermarket 'splayed' 4-bolt caps as these outboard bolts 'point' towards the sides of the block.... but, if you are like me and you want sickening torque and reliability go with a 2-bolt block and use ARP studs, these will beef up the lower end and not break the bank.
As you probably know, the stock 400 used a short rod (5".565") so use standard 350 rods (5".700") the extra lenght reduces side stress on the bores the aftermarket 6" (or longer) rods aren't worth the extra cost on a street strip motor that spends most the time on the street. I bought reconditioned rods with ARP bolts already installed and had them balanced with the other recipricating parts.
If you have any 406 questions feel free to ask...

 

I've seen too many factory 400 blocks break at the track to be able to recommend them in good conscience. .030"-over is all it's wise to consider. Stroking one is a recipe for disaster. If you're just doing this for the placard factor, that's one thing, but if you intend to thrash on it (and since you're asking about the power capability of the body, I'll assume you're planning on it), you can flush a lot of money down the toilet very quickly.

As for the body, subframe connectors will do until you need a 6-point. You'll need better lower control arms, track arm, and torque arm before anything else is needed on the frame. Oh, and poly bushings along with the SFC's.

 

So the subframe connectors can handle the 450-500hp? I'll be redoing most of the suspension as well before I even start building this motor. I hope to get it driving better than a new car within the next year or so.

I guess I should be looking for a 2 bolt block. But the selection around here is pretty slim, so I may get stuck with a 4 bolt. And I know that 0.03 is about as much as you can go with these thin cylinder walls. But it's a Chevy small block, so I don't think I'll need to be rebuilding it anytime soon.

I'm basically just trying to build an awesome weekend cruiser/show car. And maybe take it to the track once or twice. But I'm gonna need a daily driver too before I can park the Camaro. (Show car + Miami drivers = A really pissed off show car owner). There's just not enough money in the world...

But thanks a lot guys, the help is greatly appreciated.

 

What would it involve to be able to run a roller cam, in a 400 block ?

 

Roller lifters, some sort of retainer plate and a distributor with a certain kind of gear on it...

 

In my 400, I run roller lifters of the original design, before the factory mucked it up, and a cam button.

No retainer plate; no special gear if your roller cam is intended for use with stock ones (cast iron cam blank, or cast iron gear pressed onto a steel blank).

Push rods will be around .400" - .500" shorter than ones for a flat-tappet.

 

I am running a Chet Herbert Roller cam and picked up a set of used Lunati Hyd. retro-fit lifters (that has the bar between 'em. I used a cast aluminum timing chain cover (Summit) and a timing chain with a bearing between the block and gear. Pick up a button-bearing and it's easy to grind the aluminum cover until you get the proper fore/aft cam clearence. For the distributor I used a 1988 unit (small cap w/external coil) these are built for the factory rollers and have the proper gear. I pulled mine to inspect it and after 2.5 years it shows no wear).
You will need shorter push rods too but it is no big deal... My 400 with 10.8 compression, Trick Flow aluminum heads and roller cam and 6-speed manual hauls butt!!!!
Once you feel the torque planting you in the seat you will never want a smaller motor!
My 400 came out of my 1978 Chey 3/4 ton 4X4 that I bought new.
You can run a sbc 406 at over 400 hp without any durability problems (I have been doing it for years) they are a low RPM motor (remember that when selecting a cam). If you want to pull 7000 RPM you would have to go with an aftermarket block but you can build an 11 second car with reliable power by using the right combination. A guy I know has a 400 bored .040 over (408) that runs high 11's in a Monte Carlo SS with a 700r4 tranny and 3:73 gears.
Did you know that GM actually built a prototype Camaro with a high performance 400? They were all set to market it but the smog laws was on the horizion and everone was already lowering horsepower.

 

That's all it takes to run a roller cam ? I thought it involved some serious machining.

Did all 400 blocks use the same journals, small or large, whatever it was ?

 

400 blocks all have the unique 400 journal size.

 

So one can't just use factory 305 rods ?

 

Don't try to use 305 rods in a 400. If you want a 5.7" factory rod use a 350 X or K rod and replace the rod bolts with ARP bolts.

When you change the rods, the factory 350 5.7" rod's rod bolt will come very close or even hit the cam lobe on a few cylinders. This requires that you grind the top (head of the rod bolt) to clear the cam lobe in the block.
Usually you want to start with a "small base circle camshat" when using a roller cam in a 400SBC.

Some aftermarket rods are designed for more rod bolt/camlobe clearance in 400SBC builds.
All need to be checked for clearance by mocking up the motor and measuring for clearance between the rod sides and bolt head and the cam lobe. make sure the cam is positioned properly in the block (degreed in ) first as changing the installed cam phasing will affect the rod clearance.

Crane Cams has *some* "of the shelf" small base circle cams (hyd and mechanical street rollers) for just this purpose. Other cam companies can supply the cam you want on a reduced base circle if you custom order the cam.

 

I JUST got done doing a retro-roller swap!

https://www.thirdgen.org/forums/tech...ned-retro.html

 

It's the main journals that are a different size, not the rod journals.

 

Yup, it's pretty easy to install a roller cam in the 400.. and as mentioned in my post you do need to prevent the cam from "walking' back and forth and if you buy a timing chain with the 'torrington' bearing you won't have to machine the block at all.... I would use a cast aluminum timing cover tho as it really makes a good 'stop' for the 'button' bearing you will use on the front of the cam.. it's then easy to grind a little pocket for proper clearence.
As for the 350 rods, I simply bought a reconditioned set from a copmpany that sells dirt track stuff it came with ARP bolts and was a shade over $100.. not bad! Oh, and they were already 'clearenced' for the cam.. by the way, before you grind a set check it by setting the block up with the cam, crank, etc to check clearence I found that mine would have cleared okay without grinding as a lot of cams today are ground for clearence and not even advertised as 'small base'.
I will get back to you with some numbers, my block has a 509 cast into the side, these are great blocks high in nickle content..
Next time I go through my motor I am going to stroke it.. a small block with big block cubes really ROCK!!

 

If you don't buy a timing chain with a torrington bearing you won't have to machine the block at all either.

 

No, if you are running a 'regular' cam you don't but you don't want the back of the timing chain sprocket rubbing the block... a roller cam can't use the timing chain to keep it aligned, they 'walk' and this must be only about .005" or so. They make a brass 'bearing' but I don't like those.. the timing chain with the torrington bearings are narrower so block maching isn't nessesary... They call these bearings "block protectors"

 

They're not necessary, roller cam or not. A "regular" cam doesn't use the timing chain to keep it aligned, the lobes are tapered to that the lifters put a rearward thrust on the cam. If anything, a flat tappet cam has more force rubbing against the block.

 

 

How much should I expect to pay for a 400 block ? Complete engine, or without heads, at a junkyard for instance (asking so I won't get robbed lol)

 

That's going to depend a lot on the local market for 400 blocks.

You don't want a complete engine anyway. Only the block is really good for anything, the rest of it will all go in the trash.

 

Flat tappet cams do indeed have a "rearward thrust" but don't need a 'block protector' because the timing chain does indeed take some of the rearward thrust off. But that being true about the rearward force with a 'regular' cam you should realize that the roller cam doesn't have this (taper) so what is going to keep it from walking?
Depending on how much the lifter bores are off will determine how much force is pushed against the block.. I have been building high performance motors since the early 70's and I have seen more than one block that had a galled block.
If you don't want to use it fine but don't try to talk someone out of building a motor the RIGHT WAY! Steel against steel for a thrust surface doesn't add up to durability.


FYI from Jeff Smith:

Roller cams do not have this tapered ramp design, which means that other external forces can cause camshaft walk. Generally, situations like lifter bore placement, position of the distributor relative to the cam, and other factors affect the fore or aft thrust of the cam. One of the most important considerations is the vertical orientation of the crank gear relative to the cam gear. So if the crank gear is slightly forward of the cam gear, this offset will pull the camshaft forward.

One danger that exists with significant cam walk is the real possibility that the roller lifter could crash into an adjoining lobe. If this happens, catastrophic engine damage is only seconds behind. At the very least, your first indication of a problem will be metal shavings throughout the engine.

Bottom line:
Roller cam DO need to be 'contained' .....If you notice when Chevy started using rollers in their blocks they used a retainer to prevent cam walk.

------------------
Back to you vorgath, sorry... you can sometimes find complete 400 motors for $100 - $200, I have seen a ton of 'em. I was in the Pick yer Part yard in California a few years ago and found 2 complete 400 motors still in the cars (station wagons) one had the carb missing the other was complete but both cars were body damaged so they weren't likely scrapped due to mechanical issues.
I'll check around here (ARIZONA) to try to get an idea of whats out there and let you know.
Good luck!

 

The thrust button in the front of the cam keeps it from walking by limiting its forward travel. Your "block protector" isn't going to do anything to prevent forward motion.

If the timing chain supposedly takes some of the rearward thrust off of a flat tappet cam, then why does it magically not do it on a roller cam? What's so different about the two that a timing chain can counter the considerable rearward thrust of a flat tappet cam, but not the minimal rearward thrust of a roller cam?

Yes, gross misalignment of the crank gear and cam gear is going to impart a thrust on the cam. That's an assembly error.

Yes, a roller cam needs to be contained. Forward motion is contained by the thrust button. Rearward motion is contained by the thrust face on the block.

 

Thanks guys