Hot Rod Forum banner

1 - 17 of 17 Posts

·
Registered
Joined
·
33 Posts
Discussion Starter #1
Greetings and Happy New Year from the new guy to all of you out in hot rodder land.
At this point, I bring only a few questions to the table. Before, I ask them, let me throw out some info on what I am doing.
I have a 350 4 bolt main block that I just recieved back from the machine shop recently. The following things were done to this particular motor; bored .040 over, magnafluxed, main journals align honed, deck resurfaced, cam bearings and freeze plugs installed, and hot tanked. Final deck height came out to 9.025.

Other Useful Information:
The block (only) was given to me. I have to acquire/produce and or/purchase everything else; heads, pistons, rods, carb, distributor, etc. So far I have about $560.00 into the block for the machine work.

Still More Useful Information:
The car that this motor will be going in will be of the super high performance street type. No oval track racing, or drag car at this point. I want this to be a radical daily driver if I chose to do so.

Still Even More Useful Info:
This will be my first complete rebuild of a motor, although I have worked on engines my whole life. Putting it together should be fun . Getting the right parts is the delimma I face at this point. I have done a bit of research on certain parts for the rebuild, but I am still not sure which to get.

My questions:
1. Since I am not going to being screaming around the oval at 8000 rpm, could I get buy with just installing a set of ported stock chevy heads? I was initially thinking of getting the Dart iron heads with 215cc intake runners, but was not sure.

2. I was also leaning toward the Keith Black hyper.... type flat top pistons, (comp) roller cam, rockers, lifters.

3. What about the rotating assembly, any ideas with good results?

4. My last question is can anyone give me a list of parts they have used in their own machines that work good together to give me some additional ideas.

I very much appreciate any and all suggestions


Mouseman.
 

·
Premium Member
Joined
·
8,453 Posts
Welcome to the board. You are new so don’t know the ins and outs yet. This forum is intended for general introductions only. Tech questions posted here don’t get the coverage they deserve. Repost your question in the proper forum and it will have a good chance of being answered.
 

·
Time is short, are you ready?
Joined
·
655 Posts
I'll predict this question gets many opinionated responses.

Why an 8000 RPM 383? Seems like a shorter stroke would fit that RPM goal better. 8000 RRM will also require big $ in the bottom end.

That kind of RPM will also be best suited by a solid lifter cam (flat tappet or roller).

I would shy away from the hypereutic pistons for your stated goals. The fellow who built my engine has been using a lot of the Mahle forged pistons. They are a cost effective alternative to JE/SRP, etc.

Not sure on the heads, I am partial to AFR, but they are long lead time and cost a few more coins that the Iron Eagles, etc. You would probably be good to go with something like the Dart heads (200cc or better). Definitely not a stock head. Your compression ratio and cam selection will help dictate the head requirements.

Good luck, Ed www.edgesz28.com
 

·
Registered
Joined
·
4,018 Posts
You need to calculate compression ratio before buying heads or pistons. The longer stroke of a 383 will rise compression a bunch over a 350. I would guess a 76cc head with a flat top piston in a 383 would yield about 10:1 cr and 64 cc will get over 11:1 cr. A good street/strip engine with a 230 to 240 degree cam (@0.050") will need about 10:1 cr.

Try to stay away from dished or domed pistons because it slows flame travel. It is better to use flat top pistons and adjust cr with the combustion chamber size.

Stock heads will not work very well unless a lot of expensive machine work is done. And if you're going to spend that money, you should just buy a good aftermarket set to begin with.

AFR's are about the best. However, I have a set of 200cc Dart Iron Eagles and I like them because they are a simple bolt-on. They get my 2900 lb street/strip car to 120 mph in the 1/4 mile using a 350 with 11:1 cr and a CompCam 292H cam. And 135 mph with a 150 shot of N20. Not too bad.

Trickflows have some good flow numbers are are pretty cheap but require different pushrods. Go to ChevyHiperformance.com and look at their head flow data base. A lot of heads listed in there! For a hot 383, you will need a head with at least a 200cc intake port, except if you get the AFR heads then the 190cc will work just fine (big flow numbers).

As a rule of thumb....2 x cfm of the head is the max hp the head can make. And the cfm of the head is measured at the max cam lift that is being used.

Good luck with your build.
 

·
The Smell of Nitro in the morn
Joined
·
2,411 Posts
Please read the Guidelines for posting.
First off you need to learn how to use the Knowledge Base as most of these questions have been answered.
Try a search this site also.
Most machine shops will not bore without the pistons in hand.
Plus its hard to tell what parts you need without any info on the car/truck its going in.
Here is a site and take your pick of what parts you want for the application.
http://ryanscarpage.50megs.com/combos1.html
 

·
http://teamrfc.gospelcom.net
Joined
·
1,742 Posts
On a street driven 383, I would not go with a runner bigger than 200cc. As far as which head you want, it depends on your pocket book and performance goals. As far as I am comcerned, a set of older style ported stock heads is a waste of money, a set of new Vortec heads will outperform them. If you want to keep the price down, I would choose between Dart iron eagles or Vortec heads with the spring upgrade. The Vortecs with the upgrade will cost around $650 for a set from a company called Scoggin Dickdy, and the Darts will cost around $850. Out of the box, the vortec heads will produce about the same hp as the darts, (arouind 440 with a streetable hyd roller cam), but they will make arounnd 50 ft lbs more torque. If you plan on doing any porting the heads in the near future, from what i have heard, the darts react better to porting than the Vortecs, so the darts may be the way to go. On the other hand if the motor is going to be kept togather for a long time, the vortecs may be the better way to go due to the initial performance superiority. If you are thinking about buying a set of aluminum heads, I would personally go with nothing but AFR 195's, as they no longer produce the 190's, at around $1300 a set for the street 100% CNC ported heads, or around $1900 for the Compeition 100%CNC ported heads. I am not sure about the Competition heads, but the street AFRs will make around 500 hp and 500 tq.

Adam
 

·
Registered
Joined
·
33 Posts
Discussion Starter #8
Thanks for all the good information, and links.
In response to;

"Why an 8000 RPM 383? Seems like a shorter stroke would fit that RPM goal better. 8000 RRM will also require big $ in the bottom end."

I really don't want to necessarily go that high in RPM. I was thinking in the neighborhood of 6000 or 6500 max. But, I would like to go the roller cam, roller lifter, roller rocker arm route just because of the lower friction aspect which equals more power.

I will jump over in the engine forum from now on.

Thanks again.
Rob.
 

·
Registered
Joined
·
301 Posts
Check This Out

First, here's some very good info
on dynamic compression ratio and cams.

Then, a calculator to help figure things out.

Then a whole bunch of dyno tests on various combo's of small block Chevy's.

You'll note that on similar combo's, certain brand heads work much better than others. Also cams and intakes.
When you open the link, be sure to check all the pages in that link.

Enjoy
http://cochise.uia.net/pkelley2/index.html
http://www.smokemup.com/auto_math/index.php
http://ryanscarpage.50megs.com/combos2.html
file:///D:/Cars/Vette/Small%20Block/350%20Quest/Quest,%20Part%20IV.htm
http://www.chevyhiperformance.com/techarticles/76178/

Threw in a couple more good articles.

I'll dig up one more good 383 buildup, have to find it.
 

·
Registered
Joined
·
2,354 Posts
I'll interject a few thoughts for you. Since the block is bored .40 over and has been decked, you do need to look at 76 cc chamber heads if you are going iron to keep the compression below 9.5 to 1. If you go Aluminum heads, you can go to 64 cc chamber heads and stay below 10.5 to 1. If you have the bucks to spend, I would go roller all the way on the valve train as you said to reduce the friction and gain "free HP". Also, I went the EFI route and am impressed, so, again, if you can stand it, spring for the Edelbrock Pro Flo. I am using the 3507 with their Etec 200 heads on my 383. A pleasure to drive and I love the 20 MPG.

Trees
 

·
Registered
Joined
·
102 Posts

·
Registered
Joined
·
33 Posts
Discussion Starter #13
Hey, thanks a bunch. I need to read up on these links before I ask additional questions, however; I do have one for the road.
How do I calculate compression ratio when all I know about my motor is that it is bored .040 and has a 9.025 block height? I do not have any other parts.

I will look over all the links in the meantime.
 

·
Registered
Joined
·
301 Posts
Mix N Match

I'd start with how big a cam (duration) you want based on your driving style, vehicle weight, transmission, gearing, and if you want to run 87 or higher octane. Then start plugging in various
combos of heads and pistons to arrive at an acceptable dynamic compression ratio with that range of a cam. I'd start with what heads you'd prefer, then see if you can find pistons within your budget that will work with those heads to give you the target dynamic compression ratio.

Then go to your intake, header, and carb or efi combos that match the cam, heads, compression, and primary rpm range your targeting.

You need up with a goodmatching combo. You can make more power with a well matched moderate combo than you can if you have a huge cam that has an effective rpm range above what your heads/intake will support, or if your heads are too big to flow effectively in the rpm range of your cam/intake, and everything must also work with your gearing and the rpm range you'll be spending most of your driving time in.
 

·
Bowtie or Die!
Joined
·
636 Posts
Another point to consider... If your building a 383 you will have to take the block back to the machine shop and get it cleranced for the crank.
 

·
Registered
Joined
·
3,441 Posts
Clearancing the block and rods is not too hard, just time consuming. If you have a grinder and some time, I would try to do it myself. A coat hanger makes a good tester for the right about of clearance(stole that idea from someone here, but can remember who). It is a good excerise for anyone building a real engine and there are plenty of us here to help you through it. It will save you some money.

Just make sure and clean the block good after you do this. I would remove all the oill galley plugs and take it to the car wash to get all the grinding filings out. I drap towels all over the engine to minimize the amount that gets in the engine.

Chris
 
1 - 17 of 17 Posts
Top