[F-BIRD'88]

You are in Memphis. Why don't you drop into Comp Cams there and get educated.
Print out the engine-car recipe and take it with you.

[cdminter59]

If you feel more comfortable with forged pistons and rods you might want to look into a Scat 383 rotating assembly. You are buying a new crank so you might as well take advantage of an extra 28 cubes. The Brodix heads would match up with the 383 ci more than a 355 ci. Check it out at: Scat Engine Rotating Assemblies 1-90455BI - SummitRacing.com. I also thought you might would like to check out these Crower Cams. This is a mechanical roller that would benefit the heads and compression your engine has. Chevrolet Hydraulic Roller Camshaft - Performance Level 3 - Performance Levels. If you are interested call Crower and talk to them about a camshaft for you engine.

[Deathmunchy]

I was told forged pistons and rods for higher cr's. I'm not looking to run this thing off of pump gas. Its going to be primarily a track car with maybe 10-20 miles on it during the week. Car shows on thursday and saturday nights about 3 and 6 miles away.

Also f-bird I didn't think of that one. I may but like I said little skittish about comp.

[vinniekq2]

first? are you building a 350 or 383?
How quick do you want that car to go?

are you taking any weight out of it?

then we can figure how many ponies that you need to accomplish this task

[cdminter59]

In building your engine you said you not worried about running it on pump gas is this correct? Have you checked on the price of racing gas lately? Well if the compression doesn't matter you could use the pistons you listed in your parts. If I was to build an engine for racing I would want an all forged rotating assembly. You have to decide how much horsepower are you building this engine for. What times and speed do you want to turn will help decide how much horsepower you need. When you start looking at 500+ horsepower is when you want forged internals. You know the heads you chose will probably support 600 hp. Once you choose the compression ratio you want then look at rotating assemblies that will give you that compression with 64cc chambered heads. The compression you choose will also dictate what camshaft to use. You don't want a camshaft needing 13.0 compression when you only have 10.5 compression. Same with your intake match it to the rpm range of the heads and camshaft. About quench, you don't mill the heads to get the quench of .035-.045 you mill the deck of the block. The easy way is to Zero deck the block and use .040 head gaskets, but you have to have this figured in when choosing your compression ratio. Buy the bare heads and wait until you decide the camshaft you want and buy the Camshaft kit to get the springs, retainers and locks. Then buy the rest of the hardware you will need to get your heads assembled. Sorry about the book but I hope it helps.

[F-BIRD'88]

Also f-bird I didn't think of that one. I may but like I said little skittish about comp.

Competition Cams.... flat tappet hydraulic cams lifter issues.

First thng you have to keep in mind is Comp Cams sells more Cams than any of the others.
Most of the Customers-buyer are first time and or amateurs who most have no clue what they are doing
let alone install a cam correctly and break in a motor correctly.

It is only natural that With these two factors that Comp cams will have the MOST FLAT TAPPET HYD CAM ISSUES.
2. Because they sell so many of these cams, thye sell more cams than they could possibily make themselves
in there shop in Memphis. Most of the most popular cams are most likely "out sourced" probabily to the lowest
cost contract bidder.
Since the OEM's have gotten away from using flat tappet cams in assembly line motors
quality control of the cam cores and hyd lifters went for a *&^^ a few years ago.
A few of the lifter manufacturers even went out of business.
This resulted in a time of low quality hyd lifters and lotsd of cheap off shore stuff floating around.

I think Comp Cams took a bit of a bite in the *** on this. I believe they and the other cam companies and the companies that produce the hyd lfat tappet lifters have done much to address quality of late.
As the flat tappet cam-lifter market is jut too big to ignore.
Howards is a fine cam company. Howards sells a very similar mechanical street roller cam to the Comp XR286R-10 cam I recomended. But not in a Complete "K-Kit"
The comp cams Complete "K kit" K12-772-8 is a hell of a deal.
This is not a flat tappet cam. Its a mechanical roller cam.
The quality and engineering is very very good.
They require no break in but do require correct installation.
These mechanical street rollers out perform a hyd roller.
We installed afew of these in friends cars here and have 2-3 years use onthemnow on the street.
They work really well.
once of these is on the wish lift for my car.

I recomend this cam Kit for your project.

I run a Comp Cams hyd flat tappet cam in my car with no problems at all.
( mine was custom made by Comp Cams, @ Comp Cams, for me)
and I took good measures to insure a successfull run in and long cam-- lifter life.

Your mechanical street roller cam will resquire periodic valve lash checking.
It is easy to do. once , a summer is good. its done cold, takes about 1/2 hour to check.
Not all the valves will need re- adjustment. a few will need a touch up of the adjustment.
It will well worth the small maintenance effort.
(these cams are actually quieter @ idle than A extreme energy hyd cam is.)
(Mine makes a hell of a racket for a hyd cam. That is normal for these fast action XE hyd cams.)
(minor lifter noise at idle)

If the Comp Cams mechanical street rollers like the XR286R-10 were no good or not worth the money I would not recomend them. I like stuff that performs and is trouble free.
They have very extensive customer service ther as well as all the Cam companies do.
Howards, Crane, Isky, Lunati... etc They are all good.
(I like IskyCams for street strip/racing solid flat tappet stuff.)

Again,,, My Comp cams hyd XE284H-10 cam works pretty darn good.
NO complaints.

(I;ve had one ( used)) Comp cam fail on me.
It was a used cam that got swapped from one motor to another.
No fault of Comp Cams on that one.
Thats a risk you take when you swap used cams from motor to motor.

This cam I recomended for you is a solid street roller designed for trouble free street performance.
The whole K Kit is a matched design system when installed correctly in your motor.

set the valve lash cold .004" tighter than the cam card "hot lash" spec says.
Set it and forget it for 5000+miles. More power, more torque more rpm than a hyd roller.

( Howards has pretty much the same thing in a solid street roller but you have to piece together the separate valvetrain parts.)
You may find a visit-tour of Comp Cams in Memphis a real eye opener.
Remember, they make and sell more cams than all the others. Their race cams etc are top notch.
Cam /roller lifters/correct springs etc etc.)
IMHO the K12-772-8 Comp Kit is the right deal for your project.
If you build it exactly like I outlined it will G-L-H and probabily out live you.

[Deathmunchy]

@vinnie for now its going to be a 355. I'm getting a 2nd block soon to mess with the grinding for a 383.

at least 13's. Lower is better.

I'm looking into weight reduction techniques right now. I've found body kits to help. I'm also trying to find any overweight parts in the engine bay to take out and replace if possible.

@cd minter, I'm not entirely too worried about this cars gas. Its not my daily I understand though. Like I said very few miles are going to be put on after the breakin period.
Well yea. I understand what you're saying about the cam. I may be undercamming it with my choice. I'm just trying not to over cam it.
Oh oops, yes you take the metal off the block not the heads. Sorry didn't realize I fudged up there.
I'm trying to stay between 10.75-11.5 compression ratio.
Thanks for the book I appreciate it! The more info you throw at me the happier I am.

@f-bird
I'll definitely make some time to go check em out. I've never thought about it too much untill I got my idea down solid really.

[vinniekq2]

Take out the bumper reinforcement plates and the plates in the doors,thats a good 1/10 or more.

420 HP small block with 4.11s will get you into the 13s

[Deathmunchy]

Also did some reading on compression. Apparently it doesn't raise hp as much as i thought it would. Plus with the effeciency i'd gain from flat tops might be a halfway decent idea.

using
Compression Calculator - SummitRacing.com
w/ a 3.48" stroke, 4.03 bore, +5 pistons, .04 quench i'll have about 10.38:1
vs 11.54:1 w/ -3.5cc pistons.
So looks like maybe 15hp/tq lost? according to different threads and articles its not much of an area to gain unless you are literally trying to make a pure drag engine. While I would like to spending 200-400$ more doesn't seem worth it for forged pistons to gain that much. Well I learned something new.

[cdminter59]

Deathmunchy, I am recommending this calculator because it computes static compression and dynamic effective compression ratio. United Engine & Machine Co. Incorporated. The DCR is an effective way to know if your engine will use 91 octane pump gas or not. All you need is the intake valve closing @.050 which is listed on the cam card. Here is an article that explains DCR. Dynamic CR

[techinspector1]

Originally Posted by cdminter59

All you need is the intake valve closing @.050 which is listed on the cam card.

Crane and Lunati will give you that info on the cam card. Comp will not, they only give you timing at 0.006" (on a flat tappet hydraulic such as we will deal with here.) You have to figure the intake closing point @0.050" for yourself from the intake centerline and duration @0.050 tappet lift.

Here, I'll show you how to do it.....
We'll use this cam since I already have it copied.....
12-246-3 - XTREME Energy
Draw a circle on a piece of paper, about 1" to 2" in diameter. Size doesn't matter (in this case, LOL). Visualize the circle as an analog clock face. Make a mark on the circle line at 11:00 O'Clock. Mark it IVO. This will be the intake opening point @0.050". Make a mark on the circle at 4:00 O'Clock. Mark it IC. This will be the intake centerline, or highest lift point of the lobe. Make a mark at 8:00 O'Clock. Mark it IVC. This will be the intake closing point @0.050".

You see on the cam card that the intake duration @0.050" is 230 degrees. Write 230 in the middle of the circle so you can reference it. Draw a line under the 230 and write 115 (half the 0.050" duration) so you can reference it.

Now, beginning at IC, move counter-clockwise around the circle until you reach 115 degrees from the IC. You will be using up 106 degrees to get back to top dead center and will have 9 degrees left over. Write in 9 at the 11:00 O'Clock mark you made on the circle. Now we know that the intake valve opens @ 9 degrees before top dead center. We can prove this by adding 9 plus 106 to equal 115. See, that's why I had you write 230/115 in the middle of the circle, so you could prove your work.

Now, we know that the intake valve will not close before the piston gets to the bottom of the stroke and heads back toward top dead center. Therefore, going clockwise from the intake opening point, we can add 9 and 180 and find that we have 189 degrees of 0.050" duration from the time the intake valve opens to the time the piston gets to bottom dead center. (180 degrees in a half-circle). Referring to the middle of your circle and using the 230 you have written there, subtract 189 from 230 and find 41 degrees. That's the intake closing point @0.050" tappet lift. Prove your work by adding 189 and 41 to produce 230.

After you have done this a number of times, you can do the math in your head without the circle.

One of you guys could do a good deed by posting this on the wiki. I don't need any more wiki credit, let's get someone else started......

[Deathmunchy]

Yea thanks tech. Thats reassuring so I am doing that right. I typically draw the lines to represent the TDC and BDC cycle. This seems to get me the same answer so I'm going to assume it works right?

Also yea Minter I had to read that guide a few times when i first saw it before I finally grasped it. I got the idea of a DCR I do believe. Also like I said at one point. I believe with my compression and the cam and 6" rods I'd have about a 9.2 DCR.

just to check though basically the longer the cam is open ABDC the less of your stroke is actually used. But at higher RPM's the Inertia of air actually comes into play and this is what affects your VE and different RPM's?

Oh also I went by comp cams today. They said a custom ground solid roller w/lifters will be "about five hundred".

[vinniekq2]

tell comp that the cost of a custom cam should be similar to a shelf cam. If not then ask another cam grinder the same question.Comp cam sells a lot of custom grinds to crate engine builders so I doubt its a custom grind. My cam is a comp custom grind,buts its also a shelf grind for Jeff Lukovich

[123pugsy]

Originally Posted by vinniekq2

tell comp that the cost of a custom cam should be similar to a shelf cam. If not then ask another cam grinder the same question.Comp cam sells a lot of custom grinds to crate engine builders so I doubt its a custom grind. My cam is a comp custom grind,buts its also a shelf grind for Jeff Lukovich

Ageed. Comp sells at the exact same price as you can find on Summit's site. I bought one about a month and a half ago. It was a custom grind but using their standard lobes. No extra cost and they got it to my door in three days.

[F-BIRD'88]

Originally Posted by 123pugsy

Ageed. Comp sells at the exact same price as you can find on Summit's site. I bought one about a month and a half ago. It was a custom grind but using their standard lobes. No extra cost and they got it to my door in three days.

A Comp custom grind is the same price as a Comp catalog cam.

All the cam companies custom roller cam prices are going to be very similar.

the cam and complete K kit I speced for you is right out of the Comp Catalog. K12-772-8
its got all the goodies, the right specs, will deliver the goods When used on the motor/car-gear-converter-rear tire recipe I speced for you, and the price is right. Post #3
Its a complete system.