Team Camaro Tech banner

1 - 20 of 23 Posts

·
Registered
Joined
·
36 Posts
Discussion Starter #1
Hey Fellas,

I'm purchasing a 383 short block from cnc-motorsports in a couple weeks. The block they use is a 4 bolt main with a 2 pc seal and I believe it is a generation I block. The rotating assembly will be an Eagle 4340 forged crank and 4340 forged H-beam rods with forged 11.1 pistons, part # ESP-12011. My question is, should I invest the money into Miloden or equilivant main caps (approx $300) or are the basic "stock" main caps that come with a 4 bolt gen I chevy small block strong enough? The motor will be making around 550 hp. If you do recomend upgrading to better main caps, who do you recomend? Summit only seems to carry Miloden. Thanks for any help.

Jay
 

·
Super Moderator
Joined
·
32,523 Posts
If they are selling a genuine 4-bolt block, it will be impossible to convert to aftermarket 4-bolt caps.

A 2-bolt block is a better platform for aftermarket 4-bolt caps.
 

·
Premium Member
Joined
·
2,395 Posts
The stock 4 bolt main caps will be fine at that power level. I would suggest using studs.
 

·
Banned
Joined
·
938 Posts
Any engines we build that are 550 horse we go to splayed center caps. Adding studs to the block does not make the main caps any stronger as they are just a grey cast cap, Its like changing rod bolts it does not make the rods any stronger it just a better fastener.

A 383 requires good caps as a 3.750 stroke crank will side load the caps more then a 3.480 stroke crank. The Milodon caps are only nodular iron caps as we use all caps from Program Engineering which are a billet steel cap.

Splayed caps tie the pan rail and the webbing of the block together makigh for a much better peice when its done.

Have sonic test the cylinders before they do anything and an 010/020 has better webbing then the K cap blocks.

Here is a pic of a block we machined for another shop.
 

·
Banned
Joined
·
21,341 Posts
RPW,

I figure you shoulda asked Carl first..

He's about as straight a "shooter" as they come, imho AND I have NEVER done business w/ him..

As always, jmho...

pdq67
 

·
Registered
Joined
·
11 Posts
Any engines we build that are 550 horse we go to splayed center caps. Adding studs to the block does not make the main caps any stronger as they are just a grey cast cap, Its like changing rod bolts it does not make the rods any stronger it just a better fastener.

A 383 requires good caps as a 3.750 stroke crank will side load the caps more then a 3.480 stroke crank. The Milodon caps are only nodular iron caps as we use all caps from Program Engineering which are a billet steel cap.

Splayed caps tie the pan rail and the webbing of the block together makigh for a much better peice when its done.

Have sonic test the cylinders before they do anything and an 010/020 has better webbing then the K cap blocks.

Here is a pic of a block we machined for another shop.



Carl,

With an 880 casting 4 bolt block, what are your options as far as caps are concerned and what would you do since it is already a 4 bolt block? Thanks, Brad
 

·
Banned
Joined
·
938 Posts
Carl,

With an 880 casting 4 bolt block, what are your options as far as caps are concerned and what would you do since it is already a 4 bolt block? Thanks, Brad
Brad

The block in the pic is a 4 bolt block the caps I put on are 7.500 wide and go out past the outter bolts about an inch and are at a 10 degree angle which will NOT get you onto the water jackets.

Or you can go with a 4 bolt billet replacemnt cap which put all the stress on just the webbing of the block as the splayed caps tie the pan rails in.
 

·
Premium Member
Joined
·
2,395 Posts
FWIW - I've run 10.47 and 130.6 MPH with stock 4 bolt caps. Based on a weight of 3,350 lbs. I'm putting about 580HP to the tires which should be 700+ at the flywheel.

Splayed caps are definately better but do you need them?
 

·
Registered
Joined
·
694 Posts
My friend ran a true 400 CI 4 bolt main engine 72 Camaro 3000lbs running low 10's & the front tow main caps let go & destroyed the whole engine.
He had ARP main studs, second run of the day @ LACR "Hangover Nationals" & oiled down the track, people were a liitle upset.

It blew up so hard the water pump came off completely.
 

·
Registered
Joined
·
630 Posts
Jay,

What's the rest of your 383 recipe to get to your 500-550 HP goal? I am looking at doing a 383 with the same HP goal. I have been talking with Chris/John @ CNC Motorsports, Carl at CNC Blocks and a couple others trying to gather as much information before I make my final decision on who I will have build my shortblock. I will say that everyone I have spoken to or have emailed have been very helpful.

I am planning on going with a hydra roller setup in mine along with the Canfield 215 heads and Dart Koolcan intake I already have.

Tom
 

·
Banned
Joined
·
938 Posts
If they are selling a genuine 4-bolt block, it will be impossible to convert to aftermarket 4-bolt caps.

A 2-bolt block is a better platform for aftermarket 4-bolt caps.


The block in the pic I posted is a 4 bolt main so why is it impossible to do this proccedure????????????
 

·
Registered
Joined
·
95 Posts
FOOD FOR THOUGHT, AT 6000 RPM THE CRANK IS SPINNING 100 TIMES A SECOND, YOUR PISTONS ARE LIKE FASTER THAN THE SPEED OF LIGHT. PONDER ON THIS FOR A WHILE. :D :thumbsup:
 

·
Super Moderator
Joined
·
32,523 Posts
The block in the pic I posted is a 4 bolt main so why is it impossible to do this proccedure????????????
Lack of tooling, both the machine to do it and the bits to do the cutting, and most important, the talent from the operator.

I'm thinking a machinist worth his/her weight, maybe I shouldn't include females, should be able to do most anything, given the time and tools.

Most shops don't do OE 4-bolt caps to splayed caps.
 

·
Registered
Joined
·
277 Posts
The block in the pic I posted is a 4 bolt main so why is it impossible to do this proccedure????????????
Trying to learn here.

If the block is an original 4 bolt main, would converting it to splayed caps weaken the rail where the original bolt went in since there is nothing there now but a bolt hole? Or does splaying the cap actually tie into the original hole?

Thanks for the info.
 

·
Banned
Joined
·
938 Posts
Trying to learn here.

If the block is an original 4 bolt main, would converting it to splayed caps weaken the rail where the original bolt went in since there is nothing there now but a bolt hole? Or does splaying the cap actually tie into the original hole?

Thanks for the info.

The outter bolt holes are about 1 inch past the the original holes and the go into the pan rails and the cap is 7.500 wide and we plug the holes we don't use.
 

·
Registered
Joined
·
11 Posts
The outter bolt holes are about 1 inch past the the original holes and the go into the pan rails and the cap is 7.500 wide and we plug the holes we don't use.


What do you use to plug the holes and would it still work, if you didn't plug them? Just trying to learn here. Thanks
 

·
Banned
Joined
·
21,341 Posts
Carl,

Do you use sawed-off Grade-5 bolts and JBWeld to plug the extra holes??

Surely, not something fancy like "Stitch-It" plugs??

pdq67
 
1 - 20 of 23 Posts
Top