Hey Guys,

I've been very slowly collecting parts for a 383 build, and then selling them off, then rebuying blocks for about 4 years now.

I'm finally on a solid start with a cheap 400sbc 817 block I picked up with all the machine work doen ready to go, and decided to forget the 383 and go for the most cubes.

This is going to be my very first build, so please be gentle, but I can use alllllll the advice anyone is ready to offer.

The block that I bought is stock 2 bolt, and has been bored out .020. I have tried to do some research on 400 bolts and boring and have found only 1 in all the forums that have been bored to 0.020, all the others are .030 or in 0.040/0.060 danger territory, so I'm a little hesitant to believe that it is 0.020. The guy also said in the same sentence as being 20 thou over that it was a 410 block so I might need some confirmation. (Edit: pistons have been matched to cylinders and measure 105mm, or 4.1338", which is pretty close to 4.145 that would be a 20thou one yes?)
Other than that though, the block is fine.

The crank that came with needs a polish which I'll get a shop to do, but I'll get that checked out, as hand over the rods, pistons, balancer that came with it, as well as a flexplate i still have to find and get it all balanced as well.

My next dilema is the pistons / rods. The pistons are "Right Way" pistons, and apparently 0.020 oversize, but the box has no serial/part number, the site is less than helpful, and there's so easily decodable markings on the pistons themselves.
I'll add some pictures of them today.
The rods seem to be stock, no markings again, and with all the accuracy of a school ruler, SEEM to be 5.7 rods, I measured the diameter of both holes, total length from outer diameter to outer, and subrtacted the combined radius of both and came to 145mm which is a hair over 5.7.
As these where supplied with the pistons to match, I'm assuming it should be easier to tell from the pictures of the pistons as to if the pin height is correct for 5.7 rods?

I haven't purchased cam, rod or main bearings yet as I'll wait to have them properly measured in case they're oversize. ARP bolts for the mains, and ARP studs for the heads are what have been recommended to me, so I'll order them soon.

Now the fun stuff:

I have a Holley Stealth RAM with all the trimmings, 30lb injectors, 85mm Grenelli MAF, 58mm Billett Marine(or something like that name brand) TB, painless wiring harness, all new sensors, new ECU and PROMinator setup for tuning.

Heads are on their way, should be here by Monday, but are of an ex-drag car, 195AFR's 64CC chamber, 195cc intake, and fingernail wont fit between the valves. Also has 1.6 Roller rockers, unsure of springs at the moment, but will ahve those details on Monday.

Going with RetroFit roller lifters, and from what I've read will need custom pushrods.
Currently cam choice is up in the air, I hear nice things about the 280XFI HR13 from people on here, but they're usually using them on 383's.

Now that we're up to the cam, I suppose I should add the details of what I have and want.

I've got a 1985 Trans AM, currently with 5.7TPI, T700r4 shiftkitted and built to handle high HP. Diff is a pityful 9 bolt open end 2.73(7?) rear with drums. I've got access to a 97 trans am diff which I can use, but will probably need something bigger to handle the motor.

I'm in Australia, and the firebirds are rare enough here, I've wanted one since I was 2 and saw KnightRider, so naturally I want to drive it as much as possible, and have it as my daily. I've had it for 4 years and every day I jump in it it feels like the first time, it never gets old.

What I'm looking for out of the motor isn't a precise HP/TQ value, but a sound and feel I guess. I want an idle that wil have some lump to it, but not so much that I'm forever tuning to keep it from stalling. I want torque more than HP, as I'm using stock bottom end and despite a few 1/4 mile passes a year, will mostly use it to scare 4bangers on the road. Hoping it won't see over 6000rpm, but it may jump into 6500 by accident from time to time, if it breaks at that, my fault.

I definately want to feel pushed back in my seat by torque, HP is just a figure to throw around at people.

I have given up my dreams of keeping the stock converter that's in there, from doing the test everyone says I'd say it's 1800/2000max, but I have a feeling I'll need a 2200-2500 stall for this motor, i was hoping beign a 400 it might bring cam ranges down 500rpm and let it stay as is, but not sure.

So there it is as it stands. I'm looking to put the bottom end together in the next 3 weeks, and cam choice, compression ratio and head springs are probably the 3 most important things I need to get sorted.

If I've got anything wrong here so far, and I most likely have, please let know and I'll try to keep this build on track and disaster free...or at the very least take some pictures of the distasters for a howNOTtodo for beginners.

Also my work mate is supervising/building to keep me out of too much trouble, but he used to work on motorbikes and fast4s so I'll still need some experienced knowledge from the guys here to get us through.

 

Here are the images of the pistons, any insight into their origins and specs would be helpful
Again, be in awe of my fantastically accurate measuring aparatus:



The pin height looks pretty close to the top, but not having a comparison.... not sure.

Would also be helpful to know if the valve reliefs will change compression ratio much (whatever the compression ratio will eventually be)




And these are the bolts on the rods...not too sure about them, and rods look a little weak to me

 

The pistons are 4 relief flat tops. And look like a budget cast piece. the 4 relief flat tops are generally about a -8cc volume. The pin location looks stock like they would take 5.65 rods so be sure to check total height of your rod piston assembly and add 1.875(half of 3.75 stroke) to be sure it's a few thousands less than 9.025. 9.025 is the deck height of the factory chevy small block. A good machinist will be able to help you determine if the pistons and rods you have are suitable for your intended application. They will also help you determine correct deck height for the assembly and head gasket choice for total quench and CR. Rule number one of engine building, find a good machinist and follow his advice.

 

The re-builder cast pistons have a high pin location and along with the shorter 400 rods are a bad combo for performance use.You want to have good 5.7 pistons/rods and the pistons in the hands of whoever is boring the block before they do the bore.As it is standard operating procedure,torque plates are used for the bore/hone.

Mag and sonic check the block before spending nay money on it.

 

Yeah the pistons have been measured when the bore was done, and have all been numbered.
I'll find out what I'm looking at for piston/rod combo, but I'm on a pretty tight budget, it's only that i found the complete bottom end for $300 with the block work done that it all started, and afr 195 complete heads with 1.6roller rockers for $1250. My mate is doing the building etc, but doesnt have the equipment for block machining, only honing really.

I know all the money usually flows into getting the block set up, so basically I've got to work the HP/TQ back from what the build can handle as is. Will budget pistons make a huge difference if i use stronger rods? I mean $200-300 for rods/pistons would probably be the budget, and I don't think I'll hit the quality level you guys suggest, not with part prices from Australia anyway

 

You dropped money on AFR heads instead of a good rotating assembly.. Seriously, what the ****? You can always get cylinder heads later. Why the heck did you do that if you're building a BUDGET motor? I mean, bravo on the heads choice.. but once again you're doing it all backwards.

Not a chance in flying hell I'd ever use those parts, even if I was on a shoestring budget.

 

I was working on the concept that the heads are interchangeable from a 350 383 and 400. If this motor doesn't work out I can still put them on my 350, or build up a 383.

Again I'm working with what I've got. I've seen plenty of 400 builds on the forums using the stock crank, and using stock 5.7 rods, the pistons came with the motor, so that was the cheapest option.

Again I don't have experience in this and did not know what the parts that came with the block were, so the 12 year old internet flames aren't going to help me with the build.

The heads were 1/3 the price I'd pay for them here, that's why I bought them.
Now if you can point me in the direction of a 400sbc rotating assembly for 1/3 the price, I will have no issues forking out the money for that.
Again, the build is designed around what I've got. I understand the bottom end has to support the top, but I'd rather restrict the top end power to what the bottom can handle, than go over budget and wait another few years to get the bottom end.

I'm open to suggestions, if the pistons are crap, fair enough, if the rods are ****, that's fine too, but I need options, not someone saying "No! that won't work!" or "Go buy a forged bottom end for 1,2,3k!"

Also the part choices, especially for 2nd had gear is **** in Australia. SBC's aren't in as plentiful supply as they are in the states, so the sellers want what they paid for it if they sell second hand, and resellers here buy in the container load and add individual shipping costs to the retail price.

Add that to the fact it's my first build and there's a high chance I'll f*ck it up, I don't want to go for the top of the line parts to destroy. If it all works, I'll have the confidence to pull the bottom end apart and put some quality parts in, but for now a motor that turns and runs is where I'm setting my hopes.

 

See, here's the thing: you knew all of this information on parts availability BEFORE you dropped money on parts... so whether they were good parts or not is honestly negligable because you knew full well what you were getting into. You speak about a budget, and I'm telling you I can guarantee I make much less than you do in a weeks worth of work, yet I still made it happen with some of the best parts available.. most of which I'd never be able to afford unless I sat on things for awhile which is exactly what I did. That's just a sacrifice you need to make if you can't afford something. Impatience with automotive parts = massive disappointment waiting to happen.

I never said you needed to spend $3K on a rotating assembly. I didn't do it, and I don't think that's smart either when you don't make that kind of cash. I'm not "flaming" you because I think you need a magical $16,000 motor that a unicorn built for you. I know the parts availability over there. You think I don't understand that concept when in reality, I've lived here AND over there. I know exactly what the market is like for those cars and parts in both places.... and I still stand by exactly what I told you the first time you made a thread.

You're trying to have your cake and eat it too, and that **** doesn't fly with engines. Buying stuff simply to redo it later is just stupid and a waste of money. That, and if you're not sure you're going to build it right - give it to someone else that can guarantee you they can. Do what you need to do in order to build it right the first time and you won't have issues.


What I would do:
new rods with ARP bolts (forged or not, doesn't matter)
new matching forged pistons.
Get the crank checked, then get the assembly balanced together.

 

Thanks you for that.
That;s all I'm after, all the other ****, not so much. I didn't buy cheap pistons and rods, I got what came with the block. If I can use them, fantastic, but if they'll flat out crumble when the engine kicks over, obviously I'm not gonna do that.

Impatience is one of my virtues despite the 4 years of waiting i've done, I want the motor now now now, so waiting seems like agony to me, it's just my arrogant jerk nature so you'll have to excuse me for that.

Is there a brand for the pistons and rods I should look for that are best value for money?
Next question I guess, as the block was bored to match each (shitty) piston, should i get it rebored to 0.030 and get psitons and rods to match? I can get 0.030 pistons with 5.7 rods for $150 but then there's the added cost of rebore and honing.
So will it work out cheaper to keep the bit more metal on the block and get 20thou or get cheaper rod/piston and bore it out?

 

I would get Probe pistons and SCAT rods with ARP bolts if it were me. They're great pistons with a great price tag and the rods do well also. I have them in my motor. Those 400 blocks get dicey after 30 over so try to save as many rebuilds as you can.. Especially with how rare that block is in your position (and ours also). If the machine work isn't fresh you will need to get it done regardless.

Just take it slow and you'll find you save boatloads that way and not blow anything up in the process. The heads you picked were a good choice, you just need to keep doing that... Before you know it you'll be wondering how you managed to pull it off.

 

Machine work is extremely fresh, i was amazed when i picked it up, i had a vortec350 block that had done 300hours and though that was in good nic till i saw this block.
Why is the block so rare there? or is it just the bore that makes it rare?

I'll start looking for some new pistons and rods as soon as i find a bore gauge i can borrow/rent and confirm the bores.

Honestly, thanks again for the help, and I apologise if I came off as an ******* before.
I think I'm used to being a know-it-all and have been too lazy to get right down to it and learning all i need for this project, just not enough hours in the day with work.

 

I know ONE person who has 400 sbc blocks in good shape. He won't sell them to anyone. I didn't even know he had them until last Tuesday and we're very good friends. 509 virgin bore castings. You can find pistons, you might just need to get some made is all. I wouldn't punch that block out again unless you absolutely had to. The fact you DO have one that is usable and ready to go is a pretty big deal.

Buying 400 SBC's now is like going to the lotto. Most of the people that buy them are stupid because they think they'll win. Some of those people get lucky, but most don't. I know of a few people that have bought literally 5-6 blocks before they found a good one. At $400 a piece on average here, that's $2000. You could've had a SHP aftermarket block for that kind of money.

Care to guess what I'm saving up for? I know my luck sucks, so I'm not even going to think about trying it.

 

http://www.ebay.com.au/itm/WISECO-Fo...item19d418b347

would these do?

 

No, those will not work for your application. If you can't find someone to make you pistons at .020, then you should look for .030 pistons for the motor.

 

well ebay has nothing else, so i'll give a ring around some shops and see if i can find some decent priced ones. Are there any specs I should be looking for? pin height, dish dome, valve relief etc?

Wanting to run 91-93 octane fuel.

 

You want to stay flat top-. The pistons you have are -8cc. So you can see why +10 would be a problem. You want 2 or 4 relief positions in your over bore size 4.145, or have the block bored to 4.155(.030 over). You really need to know the installed deck height displacement of the rod piston assembly. You can end up anywhere from .020 to +5. This and head gasket thickness will determine your final compression ratio. As far as compression height or pin location of the positions, you should be safe if you match the pistons to the rod length you're using. You take more chances not using a machinist's help. You take more chances yet when you mix and match parts from different manufacturers and suppliers.

 

Pay VERY CLOSE attention to cam profile, or you're going to need to back out your timing in order to run pump gas properly.. which means you're not going to get the full potential of your build if you do that.

It's critical you pay attention and get your compression ratio matched properly with your camshaft/your intentions with the motor.

ASE pretty much nailed the rest.