I am planning yet another engine swap for my IROC. This time it's going to be a 400. I need to know what year(s) is the best to use. I've heard that certain years of 400's had overheating problems. I think there are other inherent problems with the 400, but can't remember right now.
If I can't find a good 400 to use, I'll just buy a Rocket block from Scoggin Dickey and start from there.
Are there any other websites that would have info on the 400?
Please fill me in on what yall know..

Thanks a lot!

------------------
AKA Pony Punisher II on all other boards.

89' Iroc-Z
ZZ3 short block-355 TPI ZZ9 cam
NOS 150 shot.
blah...blah...blah..
95' T-56, 6-speed
99' Z' rearend w/ 4.10's
------------------
1997 black Trans AM
A4, bone stock except for the Flowmaster.

 

No particular year had any more cooling problems than the other. I like using the 2 bolt blocks and have run as fast as 10.08 with nitrous in a 3700lb car with "just a 2 bolt" - Use main studs though. Gotta double check for the years, but some came with 2 freeze plugs,, and can pass for a 350 is internally balanced (I like these - yep,, it's a 350),, other have 3 freeze plugs and after checking the heads,,, that's the first thing I look for under someones hood. That rocket block is out there. Seems like Dart has a new sportsman series block that's reasonable,, if you can't find an acceptable stock 2 bolt.

[This message has been edited by BadSS (edited October 14, 2000).]

 

'89,
There is a knowledgeble cat that used to visit here....he name is RB83L69.

The man knows his 400's.

I recently bought a 400 2-bolt casting #509 (last 3 digits) based on his input. Apparently, you want a 2-bolt here, not a 4-bolt. Use studs in the mains, not bolts.

The 2-bolts have stronger webbing in the bottom of the block. Using main studs (ARP) will make for a very strong bottom end.

Most of the overheating rumors have been as a result of racer-Johnny's attempt to strengthen the block even more by using "block filler" and blocking off the steam holes in a 400. This is a no-no for street use.

I'm in the middle of a nice, winter-long, protracted study of the 400 sbc that will culminate in a serious build next spring.

If you want to share what you learn, I'll do the same. My e-mail address is oldvette@bellsouth.net

Maybe ole RB83 will hop in here - the cat's built some 400's. He can save you TONS of time just trying to match up parts.

Yup, like the right windage trey/stud kit/ oil pan/ balancer/etc. etc.

Whole lotta part #'s out there - it's easy to get a mismatch. Unless of course,

THE MAIN MAN on 400 sbc's steps up.

Let's go RB......where are ya dernit?

Alle,Alle, incomefree.......wheredobeyou RB?


BOR

 

Tips for a long-lasting 400 SBC:

1. Look for 1970-1972 Monte Carlo donors.
2. Find 2-bolt block with 2 freeze plugs.
3. Run 4-bolt caps (splayed) on all 5 mains.
4. Never bore more than .030" over.
5. Run 5.7" or longer rod for less side-thrust.
6. Deburr lifter galley to prevent cracking.

These blocks had beefier webbing and higher nickle content than others. Much stronger. They aren't too hard to find. Make sure you find a standard-bore block and pressure-test it for cracks before deburring.

Hey, cool, I've got one of these blocks!

------------------
1989 Formula, 383", DFI, Mini-Ram, S-Trim Vortech, blah, blah...
Best ET: 10.796 @ 125.8 mph

TURBO 406 PROJECT STARTED!!!

Other expensive hobby: assault weapons/shooting sports

Employed at:
Hahn Racecraft
Accel EMIC/DFI Tuning
Turbosystems & Custom EFI

Member of Midwest F-Body Association
http://www.mfba.org

 

All 2 bolt 400s are about the same. You really don't need anything other than main studs unless you are going to run lots of NOS. I know someone who is using a stock bottom end with 300 hp NOS.

Just pay your local machine shop 100 bucks for steam holes in the heads. Get a good radiator (at least 4 core) with a LOT of air flow and you will be fine. Don't skimp on heads.

third gens run great with 400s. I have a 5.7 rod (040 over) 400 and it screams.

 

Don't know 400s, but an old school friend has a 400 in an 86Z and it runs great.

Now from what I hear it's a good idea to have the machine shop tap new holes so a new age small block starter can be used. Don't know how true that is, but it's something that no one has seemed to mention.


GMI FAST what's the 3 last digests on the casting of one of those Monte 400s? This way I know what to look for when I go boneyardin.

------------------
1989 Camaro RS LO3 WCT5 "The Hose Queen" 0-60' 2.34 1/4 15.8@87mph
http://350.StreetRacing.org
ICQ: 61342629 AOL IM: BlackSunshineZ28

 

I had a 400 several years ago in a 81 cutlass.That SOB would burn the tires from one stop light to the next.
But I did have a problem with it running hot.The guy I bought it from said it's because the cylinder walls are closer to the water jackets then most chevrolet small blocks.I don't know if there is any truth to that,I don't go aroung measuring the distance between cylinder walls and water jackets ,but it does sound logical.Anyway...I found a 4 core radiator out of an older Oldsmobile that fit fine.It lowered the temp some but it would still climb up there while sitting in traffic for long periods of time.

------------------

http://www.camaroforum.com/
http://v6fbody.com/
http://nethirdgen.org/
http://clubs.yahoo.com/clubs/tristatecamaro

[This message has been edited by Kevin S (edited October 14, 2000).]

 

JCB,
I've got a plan for a 5.7 rodded 406 on paper now. The motor is on the engine stand, and I'm going to the machine shop next Sat.

Questions:
1)What compression are you running?
2)power adders?
3)Internal or external balance?

Machinist says he has all-4340 steel kit available (crank, rods) with SRP forged pistons, plus all bearings and rings for $1,775. That includes balancing - and this makes a NEUTRAL-BALANCED motor.

I like the idea of running neutral balance, because it takes the load off of the crank snout, plus allows the builder to use 350 flywheel, balancer, and flexplate. I believe the block will need to be drilled to accept a 350-style starter.

Anyway, any tips or feedback on pitfalls to watch out for in a 400 build would be much appreciated.

Thanks,

BOR




------------------
oldvette

 

BOR, maybe you can answer this...

Since I have a 6-speed in my car, how am I going to get the motor balanced?

Since all 400's are 2-piece rear main seal, they have a different flywheel bolt pattern.
Luckily Centerforce makes a custom flywheel that will bolt right up.

They make 2 different ones.
Which one should I get?

700107 - 2
CHEVROLET CAMARO 1993 - 97 W \ ENG. MFG. BEFORE 1986 EXC. 400 / 454 ENG. 153 teeth
NO counter balance

700173 - 2
CHEVROLET CAMARO 1993 - 97 W \ ENG. MFG. BEFORE 1986 W \ 400 CRANKSHAFT 153 teeth
HAS counter balance

------------------
AKA Pony Punisher II on all other boards.

89' Iroc-Z
ZZ3 short block-355 TPI ZZ9 cam
NOS 150 shot.
blah...blah...blah..
95' T-56, 6-speed
99' Z' rearend w/ 4.10's
------------------
1997 black Trans AM
A4, bone stock except for the Flowmaster.

[This message has been edited by 89ROC (edited October 15, 2000).]

 

It has 10.8 to 1
No power adders
externally bal (I only buzz it a little over 6)

 

Hey 89ROC, you might want to visit the Classic Forum over at Camaroz28.com's message board and ask for Mr. Horsepower (Chuck) He is an engine builder that knows 400s by racing experience. He has written quite a few post about building, prepping and identifing the 400s. Check him out. Also RB83L69 (as BOR mentioned) is a great resource.

What I know of the overheating wifes-tale is, yes the cylinder walls are touching because the bore is so much larger than a conventional (4.001" bore) SBC, that Chevy used steam holes to remedy this. You will definately want to drill you heads for these steam holes. Also I can't quite remember, but something about adding plugs to the deck, resurfacing and drilling them for block strength.

------------------
George P. Lara
1994 Z28 LT1 T56
1984 Z28 High Output
Member: SCCA, SCFB, SC3GFB

 

Roc,
You lost me man. Your signature says you have a ZZ series block (I presume it uses a 2-piece seal).
But your question sounds like you're planning to swap in a 400 sbc. I'll presume this is the case.

If you're going to keep a stock 400 crank, then the cheapest, most direct solution would be to run the standard 400 balancer (externally balanced) and the flywheel made for pre-1986 (read 2-piece seal) 400's.

Check with your machine shop on this, but I believe that would mean BOTH the flywheel and balancer are going to be counter weighted. The same would apply if you plan on running an externally balanced 400 crank in a 350 to produce a 383.

If a 383 is what you're after, jeez, I'd recommend looking into a new aftermarket kit such as the scat kit sold by Summit racing.

Good luck.

BOR

 

999,
Bet it's a stout mouse. I'm currently also in a 20-year battle with my own bad self as to which cam to run - the Comp XE284 (240/246 dur. @ .050) or step up to a solid with 244/244 @ .050 and run a 1.6 rocker.

If I run a solid, I'll have Comp cut me an "Extreme" fast-ramp unit like the tight lash series, except with a 108* LSA. Either way, I need the bottom end torque to match the Vigilante 2800 stall/700R4 setup I'm getting.

I'm about to quit fertin' around before the drivetrain budget goes flyin' past the $8,000 mark. AFR heads, custom crank, 4340 this, unobtainium that........you know the drill.

Ah hell, it's only money. I'm sick, just sick..........

HEY ! Red Devil !

Let me guess, you were in the garage this weekend and accidentally got zapped with a touch of 220V. Now you're on this "what if I wired 2 inline MAF's into my motor? " action.

Well, I gotta go hit my primaries with the hammer again, onaccounta' de float done stuck agin.

That's the nice thing about low-tech - usually a hammer,some baling wire, and a tube of super glue will repair most maladys.

Dad gummed coffee, it's eatin' my ahzz up.


BOR

 

It's a ZZ3 with a 1-piece rear main seal.


[QUOTE]If a 383 is what you're after, jeez, I'd recommend looking into a new aftermarket kit such as the scat kit sold by Summit racing.[QUOTE]

I do NOT want a 383. Everybody has one of those. That would be too easy anyways


Thanks for all your help.

I'll look up that guy over on Cz28.com and RB83L69.
Thanks again!

 

I just finished building a 406 for a friend. It's sitting on the dyno as I write this. During the first pull, a guide grabbed an exhaust valve and the piston smacked it. During the tear down, we found that the guide had .0005" clearance (way too tight). We had to pull both heads and hone the offended guide and a couple of others. Hopefully the dyno work will be finished tomorrow. The sucker still pumped out 396 hp / 430 #'s @ 4200 with out-of-the-box jetting and a wag at the ignition. Then the curves went flat with a bent exhaust valve.

They are a different animal than the typical SBC, but nothing exotic is required to build them to last.

I have a few suggestions that might make life a little easier for you.

First thing is to find a good block, as I'm sure you’re already aware of.

Two bolt mains are stronger than the four bolts. The main journals are .200" larger than a 350 block. When the 400 blocks are drilled and tapped for four bolt mains, the outer bolts are tapped into an area of the main journal girdle that is inherently weak. Stress fractures will/and have resulted from this. That is why GM stopped making four bolt main 400's. Splayed caps are the only four bolt cap that will hold up (at about $600 too). Unless your going to spin it past 6500, prolonged runs over 5000, or over 500 hp, I would just have the stock caps shot peened, and use ARP studs. The stock crank will also hold up to the same criteria.

When you’re looking for a block, pull the timing cover and look for a casting number. You should be able to see it slightly behind the cam gear (If I remember correctly). It will be a nickel/tin content casting number. Should look something like this, 20/10, 10/20 or one number, 10 or 20. If nothing is there, then the casting didn't have any tin or nickel added to the pour. If not there, it's not a big deal, just a better block with added tin or nickel.

Before any tool touches the block, I would highly recommend that you get it sonic checked and fluxed. If the map comes out with less than .200" cylinder wall thickness, find another block. Or, the bores can be shifted to keep the minimum wall thickness above .200" (after bore/hone). This is an option, but there aren't that many shops can do this correctly. The magnaflux will pick up any cracks.

Half filling the block is another option. Very little heat from the combustion process is transferred beyond 1" from the top of the cylinders. Half filling will stabilize the bottom of the cylinders. I've done this many, many times on SBC's without any problems.

Another block strengthening method is to install deck plugs in the 3/4" coolant holes and re-drill them to the gasket hole size.

At the bottom of the deck between the cylinders, the early 400 blocks didn't have steam holes. If not, drill them out using the head gasket as a template.

The stock rods definitely have to go. The 5.565" stock 400 rods was a GM mistake. A good rod length is the 5.7", 350 rod. I would hesitate going any longer than 6". I like the 6" rod but others here will argue this issue to death.

I've rambled much too long and have to go for now.

Later, Mike

 

I'm in the very very preliminary stages of planning a 400 for my 86. I have just some general questions while there is a good thread going on the subject.

I assume this thread is concerning the a chevy block, so what are the differences, positive and negative, between the chevy block and the pontiac block. I would really like to build a pontiac engine to go in my pontiac car, unless the positives of the chevy are much larger.

does anyone have a link or any good resources concerning this, like i said i'm just getting my thoughts on what i want to do together now. It will be EFI though...

I worked with a guy this summer that has a pretty stout 400 in his GTO and i think he said something about making the two-bolt main into a 4, does anyone have an idea about that. this is a pontiac block. the guy that helped us build the engine is a master mind when it comes to building engines, so i wonder why he would do that if the 2-bolt is already stronger?

thanks

------------------
1986 Trans Am
305 TPI
"If it's not one thing, it's another!"
http://www2.hanover.edu/hierlmeier

 

Well I am planning on over 600 Flywheel HP. I'm planning on using a 12-15 PSI supercharger, and RamJet EFI.
Would I be better off keeping it a 2-bolt?
If you use the splayed 4-bolt caps, wouldn't it be stronger? Or would that make it weaker?
Thanks!



------------------
AKA Pony Punisher II on all other boards.

89' Iroc-Z
ZZ3 short block-355 TPI ZZ9 cam
NOS 150 shot.
blah...blah...blah..
95' T-56, 6-speed
99' Z' rearend w/ 4.10's
------------------
1997 black Trans AM
A4, bone stock except for the Flowmaster.

 

Howdy again,

If your going to boost or squeeze this sucker, then I would install the splayed main caps (with the two bolt block). The criteria of 500 hp, extended high rpm or blasts past 6500, is my personal comfort zone. I know others who have success with the stock crank and two bolt mains and studs at much higher levels of power. I won’t go there. The people I build engines for are family and friends (very persuasive ones at that). I want their engines to hold together.

With the stock four bolt mains, all bolts are run straight down into the girdle. With splayed mains, the outer bolts are ran at a 20* angle towards the pan rails. This is a much stronger/stable area of the block. The Bow Tie, Rocket and Dart blocks (and many other aftermarket performance blocks) come with splayed mains.

It will cost you about $600 to have the splayed mains installed. $300 for the caps, and $300 for the machine work. With a used block, the machine costs and initial cost of the block could very well start to compete with the cost of an aftermarket block. I've got receipts totaling $1700 for block machine work alone on the 406. Roughly $500 of that would have to be spent on a new block anyway, (sonic mapping, cylinder bore/hone, line hone, decking) but if I was to do it over, I'd start with a new block.

The Rocket block isn't a bad deal when you start adding everything up. It also has a raised cam location, spread pan rails, splayed mains, thicker cylinder walls and a tall deck. You can easily stroke it to 434 with 6.125" rods and not have any clearance problems.

There are a few things unique to the rocket block that you should be aware of though. Custom timing set, oil pan, pistons and distributor length are all required. These are not that uncommon to the race engine world and done quite frequently, but they are at a slightly higher price.

With the kind of power your contemplating, you should also be looking at forged internals (crank, rods, piston). Scat or Eagle makes an excellent product at a very competitive price. The JE srp line is a high quality piston at a reasonable cost. They have a high silicon content allowing you to run tighter clearances. With boost, you'll have to run the pistons a bit looser, so look for pistons with the tightest clearances you can find or get used to hearing piston slap. Another added benefit with a forged rotating assembly is it's easy to internally balance (no Mallory). You will also want to get a "good" damper.

Mike

 

Where could I buy all these custom parts? I've never seen them for sale in any magazines or anything.
The Rocket block was my original plan, and I very well may still do that, considering all the costs of a production 400.
I appreciate all your input Mike!
Thanks

 

Pistons: All of the higher end piston manufactures will custom build a set of pistons for you. JE, Arias, BRC, Ross, ect..

Oil pan: Hamburger, Milodon, Morosso all make pans for the rocket block. You need to make sure that you talk with the tech. dept. and get the correct part number. You'll also need to match the pan to the vehicle it's going into and what capacity, traps, windage tray, scraper, ect... you want.

Timing set: Cloyes will make any set to any length. Same thing, call their tech. dept.

Distributor: Depending on the final deck height, the intake will be sitting higher or lower than stock configuration from the cam. It's just one of those headaches your about to experience when going outside the relm of "stock" configuration. It's all been done before, so you not a pioneer be any means. Just means a little more pre-thought and planning. MSD or High Perfomance Distriburors will custom build a distributor for you if needed. You may be able to get away with shims or have the intake machined. You wont know for sure until the intake is sitting on the gaskets.

Here's a string you might find informative.

http://corvetteforum.com/ubb/Forum7/HTML/004536.html