Engine build

Mikej · May 18, 2006, 04:55:19 PM

I have a 350 block at the machine shop. Had to bore .060 over. Going to deck the block for zero deck height and use a .043 head gasket for the quench. Is this correct? Also will be shooting for 9.5:1 compression. Will be using dished pistons and what ever cc heads to get the compression right.
The cam I'm looking at is as follows: Hyd. roller 1.5 rockers 282-284 adv. 230-232@.050 510 lift 110 lobe 106 centerline 2000 to 5800 rpm.
For the street. Thoughts
Four bolt main block out of a combine(truck block) with a forged crank.

EMSjunkie · May 18, 2006, 05:18:29 PM

If memory serves me, and it prolly don't, :? , .060 over is about as far as you can take a small block chevy.

I would be concerned about overheating, since the cylinder walls are gonna be fairly thin.

or...................I may just be F.O.S. as usual. :oops:

I bet somone will straighten me out.

Vance

1FATGMC · May 18, 2006, 08:43:47 PM

Quote from: "Mikej"I have a 350 block at the machine shop. Had to bore .060 over. Going to deck the block for zero deck height and use a .043 head gasket for the quench. Is this correct? Also will be shooting for 9.5:1 compression. Will be using dished pistons and what ever cc heads to get the compression right.
The cam I'm looking at is as follows: Hyd. roller 1.5 rockers 282-284 adv. 230-232@.050 510 lift 110 lobe 106 centerline 2000 to 5800 rpm.
For the street. Thoughts
Four bolt main block out of a combine(truck block) with a forged crank.

The quench is good. I would decide on the heads first. They are the most important item. Then pick the pistons for the compression you want, but that will be tied to the cam. If you run that much cam (what you stated) you could get away with more compression as the cam will bleed some off. You need to pick the oct. fuel you want to run.

More important than static compression is your DCR (dynamic compression ratio) which almost everything influences, but mostly the cam and initial static compression. Here is a good link on this where you can figure it all out:

http://cochise.uia.net/pkelley2/

Your compression is also going to be influence by the head design -- aluminum or iron, new efficient combustion chambers (like vortec and others) or old style combustion chambers. You are on the right track with the dished pistons. So work on head type, combustion chamber size and dish piston size to get your DCR where you want it for the oct. gas you want to run.

You mention "Hyd. roller 1.5 rockers". Are you saying full roller rockers? Roller tip? Roller cam?

I think your cam might be a little much for a street car if you want to drive it a lot, but if it just goes out on weekends and you don't care about mileage it is probably ok, but you need to find a cam that works with the heads you are going to use and the intended use of the car.

Building it with the quench at .040 you need to be careful with assembly. GM puts in more to account for differences in parts tolerances (rods, block, pistons) that can all add up and end up being too close and then the piston can hit the head and or valves. So at .040, which is good, you are going to have to check all the cylinders to make sure you end up with probably no less than .030 clearance on any of them. Just make sure none of the pistons are "out of the hole" on final assembly.

I'll help more if you need it or want it,

Sum

Crosley.In.AZ · May 18, 2006, 09:06:01 PM

Quote from: "EMSjunkie"...................I may just be F.O.S. as usual. :oops:

I bet somone will straighten me out.

Vance

I ain't gonna say anything here

Bib_Overalls · May 18, 2006, 11:51:08 PM

I zeroed the deck on the motor in my roadster and use FelPro 1003 head gaskets. They spec .039 under torque. I used Keth Black "D" cup pistons. They have a flat area that matches the flat area of the heads that are inside the combustion chamber. I am running Vortec heads with an Edelbrock Performer cam and about 9.2/1 compression. Runs like a top on 87 octane.

1FATGMC · May 19, 2006, 01:04:15 AM

Quote from: "Bib_Overalls"I zeroed the deck on the motor in my roadster and use FelPro 1003 head gaskets. They spec .039 under torque. I used Keth Black "D" cup pistons. They have a flat area that matches the flat area of the heads that are inside the combustion chamber. I am running Vortec heads with an Edelbrock Performer cam and about 9.2/1 compression. Runs like a top on 87 octane.

Hey that is good to know. I'm getting ready to order the parts to put a 383 sbc together for Julie's Ford pickup. I'm getting some new vortecs from the guy who will do the machine work that have been modified for more valve lift, but won't use that aspect now. I want to make sure the motor runs on 86/87 octane and thought to make sure I had better stay in the high 8's on the compression, but it sounds like from what you say I'll be able to go 9.1-9.2 and still run the cheap stuff. I plan on a zero deck also. Do you know what the specs are on that cam? If it is the regular performer cam I see in Summit it is 204/214 at .050 with .420./.442 lift. Does that sound right? Do you know what your dish cc is with the pistons you have?

Things will be different with the 383, but if I can figure the DCR of your combination and get the same with mine I should be safe with the 86/87 oct. gas.

thanks,

Sum

Mikej · May 19, 2006, 12:10:51 PM

Thanks for the site. Don't know if I can absorb all the info but will give it a try. I will be using aluminum heads but don't know the cc yet. I do want to be able to run 91 octane.

Mikej · May 19, 2006, 01:49:31 PM

Is there advantage between 64 cc heads and 73cc heads other than compression?

rumrumm · May 19, 2006, 02:00:51 PM

It is better to run a small combustion chamber than a large combustion chamber to get your desired compression, but it is more important to run a head that has the new swirl design combustion chamber because it is more efficient and you don't have to run as much timing advance. My 383 runs best at 32 degrees total. What kind of aluminum heads are you looking at?

Mikej · May 19, 2006, 03:28:05 PM

Lynn, I don't know yet. I'm open for suggestions. For right now I'm working on the bottom end but need to make sure I plan for the chamber size.

rumrumm · May 19, 2006, 05:20:20 PM

AFR has a new head design that is supposed to be a major improvement over their present heads (which are the best flowing aluminum heads on the market). Go to www.airflowresearch.com. I don't know if they are available yet, but they should be shortly. That would be my choice. I am running a set of AFR 190's on my 383, and it makes awesome power.

1FATGMC · May 19, 2006, 08:47:51 PM

Quote from: "rumrumm"AFR has a new head design that is supposed to be a major improvement over their present heads (which are the best flowing aluminum heads on the market). Go to www.airflowresearch.com. I don't know if they are available yet, but they should be shortly. That would be my choice. I am running a set of AFR 190's on my 383, and it makes awesome power.

Lynn, you are a lucky man. I'm using vortecs on Julie's 383 since it will just be a basic torque motor, but sure hope I can afford some AFR's for the 383 I'll build that will go into 1FATGMC. I think they are the best out of the box heads you can buy and that is even the old ones and the new ones are suppose to even be better like you said.

Mike if you are looking for some less expensive aluminum heads a lot of the guys on http://www.chevytalk.org/threads/postlist.php?Cat=&Board=UBB64 like the Edelbrock E-Tec Heads. They are like the vortec and require a vortec style intake.

There is a lot of debate if aluminium build more HP than iron heads. They are both good. AFR's are great because they flow so good, not necessarily since they are aluminium. Aluminum can take more compression, but on some tests I've seen where the manufacture has the same head in iron and aluminium they both made about the same hp, but the aluminium need more compression to keep up with the iron.

If you look at iron heads I would also look at the new "Platinum Series" Iron Eagle from Dart and guys are making great hp with vortecs that have had the valve work done for more lift.

I have some flow numbers on my site for some of the heads and look around the internet for some of the newer head flow numbers:

http://purplesagetradingpost.com/sumner/techinfo/heads1.html

Personally I would stay away from the Trick Flow heads that rotate the valves in the head, but their regular 23 deg. aluminum head is not a bad head and I see Brodix has a new aluminium head for about $1000.

There are a lot of good heads out there, but if you want the best, got the money and can wait a little bit the AFR's are the king.

c ya, Sum

rumrumm · May 22, 2006, 09:23:16 AM

Good post, Sum. You nailed it.

Mikej · June 04, 2006, 08:47:15 PM

Finally, I got the calculator downloaded. My scr is 9.7 and the dcr is 7.618.
This falls within the range for 91 octane but on the low end. Is this ok? Does this mean it would run ok on lower octane? I don't want to raise the scr incase I put a blower on it someday. Thoughts.

1FATGMC · June 04, 2006, 11:06:44 PM

Quote from: "Mikej"Finally, I got the calculator downloaded. My scr is 9.7 and the dcr is 7.618.
This falls within the range for 91 octane but on the low end. Is this ok? Does this mean it would run ok on lower octane? I don't want to raise the scr incase I put a blower on it someday. Thoughts.

I would say with the 7.6 you are probably close to running on 89 oct.

Read this post on Chevy talk:

http://www.chevytalk.org/threads/showflat.php/Cat/0/Number/1540249/an/0/page/2#Post1540249

c ya, Sum