I'm getting the engine from a friend that's had it sitting in his garage for about 20 years. He says the thing has never been opened and doesn't have a whole lot of miles on it.

My questions:
1. Should I be able to install my Sportman II heads, RPM intake & a roller cam on the engine and run it ?
2. Should I / Can I perform a compression test before doing the above ?
3. Is there anything I should watch/ look for when I get it on the engine stand ?
4. Did these come with forged cranks?

Thanks :cheers:

 

okay, here is my best shot

1. The Sportsman heads will work if you drill steam holes for a 400. RPM intake will fit, roller cam will work if it is mechanical or reto fit hyd. roller not an o.e. hydraulic. The cam will be be milder in a 400 than smaller displacement small blocks

2. You can do a compression test, however if the heads that are on the motor now have any problems, (i.e. bad valve seats, etc. ) it will not be correct.

3. When you get it on the stand Check all tolerances. No point in throwing good parts at a junk motor. Do it while it is on the stand and save yourself some headaches later.

4. No 400 came stock with a forged crank.

:cheers:

 

Why would you risk it?
Let me tell you a story. My grandma had a 400 Pontiac motor in a station wagon that had never been abused. Infact it had never been driven over 50 mph! It was a 1973 Pontiac Safari that she bought new. I gave it to my friend to put in a T/A. He was hell bent on just putting in a cam and a set of "hot" heads and a set of headers on it. I tried to talk him out of it but he wouldn't listen. All that work and in less than 500 mile he blew it up! My god it wouldn't have been that much more to freshen up the bottom end!
To this day he regrets his decision. Don't do it! A chevy bottom end is too cheap to freshen up!
John

 

You mentioned that a roller, not OEM hydraulic will work in a small block 400. I was curious why a standard hydraulic will not work. I have a 406 with a roller cam that I was thinking of changing to hydraulic flat tappet when I rebuilt it. Is that not an option?

 

What he meant was the factory type roller cams/lifters for the 87/88 and newer blocks. Any aftermarket roller for the "old style" block will work! Yes you can change back without any problems. :cheers:

 

Thanks guys. I think I'll go with a freshening up (new rings & bearings initially) & install the other parts for now. Afterwards I'll save up for the forged stroker kit that I'd like to put in. I'm thinking the 427 would be real nice with ~550 torque & hp numbers :) .

 

If I were to do it over again I would build a 427 small block. This is a great combo. I've ridden in a 600 HP 421 small block in a street Camaro. (Driven it too). Nice motor. You can't nail the throttle or it will break the tires loose in any gear. (4.11 rear). This thing will turn 7600 rpm and is as smooth as any motor I have driven. Go for the freshen up and when you can roller cam and big heads and it will really put down the power.

 

Gordon, I'd love to hear more details on that motor if you have any :yesnod: ! That sounds just about perfect ;) .

 

I can get all the details you want. It is in my brother in laws Camaro. He had it built by a pro and went wit hthe milder cam. They were looking for around 670 with the big cam and I'm pretty sure it gets right at 620 with the small cam. BTW it is only a 421 ci in. If you want the details let me know and I'll have him send me everything on it. It was not cheap but they went with the best of everything.

 

:eek:
First of all, the 400 Pontiac and 400 Chevy are NOT the same motor.
The Pontiac version is related to the 421 and 455. Its weak link was the connecting rods, which are weak with stock rod bolts. Upgrade them to ARP rod bolts and the Poncho rods will live.

HOWEVER, we are talking about a Chevy 400 small block here. You do not want to run that 400 stock. The connecting rods are extremely short and have such high side-loading that the block tended to crack at the cylinder bores. So at a minimum, you must increase the rod length to at least a stock Chevy 350's, 5.7 inches, and preferrably, get 6 inch forged rods.
Also, plan on magnafluxing the block to check for cracks.

On the stroking issue, don't do that unless you have deep pockets. Stroked 400's are powerful engines, but will cost you big time! I built a 427 big block because even tricked out, it was cheaper than building a 434 small block!!! Thousands cheaper.
Also, stroker cranks reduce the rod/stroke ratio back down, making them lazier revvers. Instead, a long-rod (6-inch) 406 will rev as well as a 350 and make tremendous power. You should see at least 400 hp to the rear wheels.

And yes, you can use your Sportsman II heads, but work will have to be done on them. Each one will have to have no less than all 6 steam holes drilled, and you really should get them fully ported to help that big 400 breathe. Oversize the intake valves to 2.08 if you can afford it.
Do not listen to any machinist that tries to tell you not to drill the steam holes, or to only drill 3 of them. GM already does the minimum required work and they felt it necessary to have 6 steam holes. I wouldn't second guess them!!!

I have a friend who runs a huge cammed, long rod 406, and he's putting out about 545 horsepower at the crank. He runs low-12's to high-11's straight up with no nitrous at 4400 feet altitude. He threatens the 10's with a 175 horse nitrous shot. That translates into low 4-second 0-60 times. Fast enough to beat almost anything out there.

And you'll save thousands by not stroking the 400.
That's just my opinion though. :cheers:

 

I agree with Momo. The engine I'm talking about was 11K. Big dollars. Its got long rods a crank that is very light and pistons and rods that are very high dollar. Runs great but a lot of money

 

I was messing around with DD2000 last night and came up with a 575hp 421 with an incredibly flat torque curve. It was 10:1 compression with AFR190 and a nice roller cam.

Gordon I'd still be interested in hearig more about your brother in laws, even if I don't go full blown like his, maybe I can pickup some tips & tricks ;) . This is an engine I'll be building as I can, I'll run my 350 until I'm ready for to install the 400 :) .

Momo I'd love a BB, but love the way my car currently handles with the sbc and would hate to get away from it. If I can get away with a sbc w/ BBtorque, that may be the ticket :D .

 

His is a little wilder. The crank is a lightened Lunati crank with Oliver rods and custom pistons. He is running a true 11.1 compression. The heads are AFR 227 race heads. The 190s you mention are way to small for anything over 400 ci in for real power. They did a small amount of work on the heads. The cam is a roller around .260 dur @ .050 and a lift of around .650. Don't have the exact figures but these are close. A Victor Jr intake and a heavily modified BG 850 carb that flows around 950. He is running a MSD 7 ignition system. 1 7/8 Hookers and a 3 inch exhaust with some big Flowmaster mufflers. His weak link is the trans (M21) and the axles are stock 12 bolt. He has only managed a 12.0 at 120 but this is with street tires and being real easy on the drive train. A similar motor with the bigger cam in a 2600 lb car set up for racing ran low 10s with a couple of high 9s. In his car it should be a low 11 high 10 second car if everything was setup for racing. It feels like it too. It pulls hard in every gear and at 120 is still pulling very hard. Scary ride but fun.


[Modified by Gordonm, 5:15 PM 10/13/2002]

 

Thanks Gordon, those are exactly the kind of things I'm looking for :yesnod: ! I'm going to save this to refer to later :) .

 

Mike. If you need info on a "434" SB, it's a real BEAST. Mike Miller's got it in his Grand Sport Replica. Pictures on my web site. JCL :yesnod: "Have Baffles.Will Travel"

 

Thanks Jim. I'm not sure if I'd be comfortable going that far with a stock block. If I was getting an aftermarket block, then the 434 would be the easy answer ;) . :cheers:

 

Mike I agree with you on this. The stock block is a little shaky at those cubes. The guy who built the motor I'm talking about is a pro. drag racer and has held many class records. He said the 400 block is OK to 427 and about 650 HP. After that it gets shaky. he has lost a few motors due to bad cores on the block. He was even shaky on the 421 over 650 HP for a street car. He has a 750 HP 421 on a race car but does not have to worry about getting home. It runs in the 9s. There are plenty of 434 motors out there but I'd rather be safe than walking home.

 

Gordon (& others)- I just got back from the guy's shop that built my current engine. There were 2 other guys there and when I was telling them about my idea to build up a 400sbc, they all pretty much frowned upon this :( .

They all basically said that the production 400 doesn't do well with higher HP. They all said that these blocks crack around the cylinders because of the poor cooling issues in the block. The think I'd be better off stroking my engine to a 383 or going with an aftermarket block if I want 400+ci's.

Now I don't know what I should do :confused: . The guy that built my engine has a great reputation locally. I can get this 400 for $200 complete & not sure what I should do now :nonod: .

Any comments welcomed.....

 

I too have been wanting to build a 427sb.If you look into a complete machining of a stock block it'll cost about 1200.00 with splayed caps plus the cost of the block typicaly 400 now your at 1600 give or take.For I think 2100.00 you get a ready to assemble new motown block that's ready for the job of 600+hp,or better yet buy a assembled short block from Bill Mitchell Hardcore racing for 3500.00 stroked to 427. Don't hold me to it on those prices it's been awhile since I looked at them,maybe some else can comfirm them

 

Mike, I did a TON of research when I settled in on mine (an old 400 block)and heard the same stuff. I could never track it down to first hand knowledge though.

It was always the same old thing...........guys heard it from a friend of a friend of a friend. I was concerned too, so I asked the guy who's doing the short block on mine (he has built dozens of 400s with both new blocks and old blocks). He told me an older 400 block is just fine (assuming it's been magged) if it's not gonna see 50,000 miles a quarter mile at a time. :lol:

He went on to say a hogged out 400 on street duty has no more tendency to have problems than a hogged out 350, street duty being the operative phrase here. He did tell me I'd be crazy to build an older block any further than .030 over and/or beat on it regularly. It seems to me it's just a matter of what your intentions and driving habits are. Geeze, I hope he's right :lol:

On a side note, did you get my e-mails last nite? My home computer is giving me fits. When I get back in tonite (10pm eastern) I'll check and re-send if necessary :cheers:

Tim