I've been looking for a cheap (max $50) set-up block for my car to use in setting the motor mounts. I'd found several, but too far away to be worth the drive and shipping would cost more than I wanted to spend for something I'd probably throw away again after the mounts were in. Yesterday I made another round of calls to some local salvage yards, including one I'd missed before. Guy said sure he had a block for $50, come up and take a look.

Turns out it's a virgin 4 bolt main "010" casting block. Now the question is, how long a stroke can you clearance a stock GM casting for? I'm planning a 396" motor, so would need to clear a 3.835" stroke. Is it worth trying to clearance this block (after all, I've got SO MUCH money in it I'd hate to wreck it ), or would I need to go to a World or Dart block to clear the crank?

-Greg

 

A production block can typically take a 3.835" stroke, especially the older blocks which your '010' is. On some of the newer blocks, I've seen them have to fill the block about an 1" or so because they would grind through to the water jackets. In an effort to save weight, GM started making blocks lighter and thinner in the mid 70's on. You can go to a 4" stroke with a production block, but you're really pushing it, and you're almost guaranteed to have to fill the block a little.

One thing that helps alot is to use "stroker" profiled rods. Most of the better companies like Crower, Lunati, etc offer them, they have profiled shoulders which reduce the amount of clearancing required, as well as interference with the cam. Speaking of which, you'll need to use a small base circle cam with the 396 and up stroke, with a standard cam location block.

That's an excellent price for an unbored 4 bolt '010' block. I've seen them go for as much as $400, if you can even find them. They are starting to get rather rare.


[Modified by Monty, 7:30 AM 10/3/2001]

 

Thanks. I was aware of the small base cam (luckily most of the rollers I've been considering already are), and would probably use a set of cap screw H-beam rods, which should help with the clearances.

Any experience with how much the bottom of the cylinder bores need to be notched?

-Greg

 

I personally haven't run more than a 3.75" stroke in a production block, I'm using a Dart IRon Eagle/Rocket Block with my 4.00" stroke. But I have seen some 396's at the machine shop that were built using production blocks. The clearancing really wasn't that much more than a 3.75" requires, remember that the increase in stroke is divided in half, in terms of what additional clearancing is required - so you're only talking about a difference of .08" or so, hard to see by the naked eye. I would estimate the notch was about a 1/4" radius, that was with cap screw stroker rods, like you described.

396's seem to be pretty popular with the C4 guys, if none of them chime in here, you might want to pose this question over on their Tech board. Several of them have More Performance 396's.

 

To make a 396 you need to buy the 3.875 and in my opinion it's the way to go. It's not really the stroke that you have to worry about it's the size of the rod bolts. Just use a search engine on stroker small block chevy to find kits.

4 inch is a must fill the bottom of the block operation on the passenger side.

Beware - you can get lot's of money rapped up in a small block. So it's best to figure it all out. Big block & blown small blocks are very cost effective.

 

Monty - Thanks for the tip on More Performance. I'd been having a tough time finding piston listings with the right compression height to match the 3.875 crank, and they had some listings (to go with 5.85 rods). Looks like a 396" combo should be possible. And after all, the car is a '65 so a 396 is a "correct" restoration engine, isn't it :D ?

-Greg

 

Greg,

You might be skating on thin ice if you go with a SBC 396 if a BBC 396 is factory correct for your car. Even though it's an SBC vs. BBC, some wise crack judge my give you a point for at least having the correct displacement, defeating your "Project No Flight" goal ;).

 

Greg - if you go back and search this section of the forum I might have listed some vendors web sites. I found one place that i wished I would have known about before my project. They seemed to have every stroker kit you could every want 3.75, 3.80 3.835 3.875 4.0 with 4340 6 inch bushed with your choice of piston and rings

I have a 383 and a 393 393 is a 3.835X4.040

So your the one who was trying for a Zero point car! :lol: The lady from the national corvette Museum glanced at my car and wouldn't even allow me on the judging list.

 

Actually it's change to a "No Flight" car (courtousy Chuck G) as if the car runs (which I hope it will some day) you get points for the operations section, which would blow the Zero total :D.

I'll check the archives to see what comes up. If you find any good sources feel free to pass them on, as I won't be getting into motor "internal" stuff for at least a year yet ... to much chassis work still to go.

-Greg

 

Looks like a sweet project, the idea for the 396 is really cool too. I heard with that stoke you have to shave the tops of the pistons .100" if you run 6" rods. So what kind of build are planning? mild or wild? I'm hopin (as the rest of us here are) thats it'll be wild, and if you project is any indicator it will be. Maybe you can be the first to try the new Brodix 18x heads.

 

George, is that your daughter in your car - her name isn't Shirley is it? ;)

 

JE and others sell the really high pin 3.875 & 4 inch. Requiring no mods with 6 inch rods. Monty is using 6.125 rods now and my 355 alky injected had 6.125 to help turn 9000 rpm.

Yes that is my dau. by the time she was 8 she could tell people all about it in the pits

 

The goal is 500 HP, which should be enough if I can keep the weight down (hoping for under 2500#). The 396 combos seem to go with a 5.85" rod, and there are pistons made for that rod with the 3.875 crank. Looks like a complete recip set runs about $1500, which is pretty much the same as for a 383 with similar quality parts. Think I'll skip the 18 degree heads, the custom valvetrain is a tad pricy and this doesn't look like a low budget project already.

-Greg

 

Greg,

Those Brodix 18x heads that Keith recommended do not need shaft mounted rockers. I haven't used them or seen them yet, but based on the advertisement/claims by Brodix, they look appealing. 325cfm with standard 23* valvetrain for around $2000.

 

From my understanding 5.85" rods were used with the 3.8xx stroke so that normal small block chevy pistons could be used without modifications.

 

GregP I think needs to check that last post before he spends lots of money on pistons that he didn't need. :)

 

I was looking at the Brodix catalog and the 18x heads do require 18* pistons, but they don't cost any more than regular custom pistions really. I ordered a set of custom JE 18* pistons for my motor and they were $74 each. The 18x heads require ARP head studs for 18* heads which feature a 3/8" stud between the two center exhuast springs, but that's no big deal either. You can use standard lifters and standard 7/16" roller rockers or you can use Jesel/T&D shaft mounted 40/60 spaced shaft mounted if you want. You will need custom length pushrods as well, but that's not a big deal either. Just mock it up with an adjustable pushrod to determine your required length and then just order what you need. Also, Brodix says that the heads use a standard 10* intake face angle.

Here's Brodix's out of the box flow chart (cfm @ 28")

LIFT----------Intake--------Exhaust
.200-----------157.0---------122.3
.300-----------212.4---------164.2
.400-----------259.6---------199.6
.500-----------302.6---------217.3
.600-----------318.9---------226.0
.650-----------321.6---------229.9
.700-----------325.2---------232.5

Those are kickass numbers. For comparison, my Dart CNC ported 18* heads were flow tested and made:

Lift--------------- Intake---------Exhaust
.200-----------------132----------111
.300-----------------197----------188
.400-----------------258----------224
.500-----------------309----------242
.600-----------------346----------253
.700-----------------355----------260

As you can see, those Brodix heads flow extremely well at low lifts and flow 300+ cfm from .500" up. The exhaust ports are pretty good too. For $2200 complete, they are a very good deal.





[Modified by Monty, 12:14 PM 10/27/2001]

 

Yeah, Greg if you do use the 18x just run a longer con rod since you'll need the custom pistons anyway. If you stick to more normal 23* heads and use the 3.875" stroke crank, an of the shelf piston can be used with 5.85" rods.

 

The pistons I've found so far for the 5.85 rod are custom to that setup. The compression height is 1.213". A "stock" piston for the 3.48 stroke and 5.7 rod is 1.56", and with a 6" rod is 1.26". For a 383 motor (3.75" stroke) a 5.7 rod is 1.425" and a 6" rod is 1.125". I don't see how going to the 3.85 rod would make any of the "stock" combos work.

-Greg

 

You can buy anything you want. Clear from 5.6, 5.7, 5.85, 6.0, 6.125, 6.25 and the pistons to match common strokes 3.00, 3.25, 3.48, 3.50, 3.625, 3.75, 3.80, 3.835, 3.875, and 4.00.

It's not like the old days where you had to figure things out. Now you just call a 800# and they send you stuff next day air.