so , then I guess I should leave the dish pistons in the block, put the crank kit in .

that will leave about 350 bucks, if vortecs aren't worth messing with, what casting number stock head should I look for, every body seems to want 400-500 for a set of double humps around here.

 

For performance use a 'D' dish, not a stock dish piston is required.

Have you sat down and built the engine you want/can afford on paper? That is the place to start. Do research to match available budget and parts to needs.

 

Dude, just replace the crank and bearings and con rod bearings for now, and put it back in and run it. Save up until you can do something real. Say, a grand for heads and a cam.

There's two ways to make a budget. First is "What can I do with the money I have right now?" Second is "How much money do I need to do what I want?"

Scott

 

I don't know where you are, but where I am, double hump heads are worthless.

 

They were the shiz-nit 40 years ago. Now? Not so much. You can buy decent aluminum heads for a little more than 700 bucks. Floteks from Speedway Motors. You can get really good heads for about 1500 bucks, like AFRs. It's just plain nuts to spend any money messing around with those old iron heads.

Scott

 

picked up a set of 906 vortec's for free. but budget just went south with an unexpected bill.
I'll keep saving.

 

I've got 906 Vortecs on my 383. A couple weeks ago, in mediocre conditions, it ran 12.35 at 109.49, so they won't hold you back too much.

 

they work great on my dirt track 57 chevy.

 

The absolute worst thing you could do would be to crack a running engine for a half-assed "overhaul" by replacing bearings and rings. If the compression and leak-down is good, then spend your $$$ on an upgraded cam, Q-jet overhaul and a good tune.

A stock set of GMPP Vortecs will significantly outflow any stock head at a cost only slightly more than having that stock head rebuilt. There are better heads for more money, but be sure to match the power output to the rest of the engine...and the chassis.

Figure on a low-buck (but quality) overhaul at around $2,000 if you want to make a little less than 1 HP/CID.

 

by budget build I mean using parts I have and just adding has little has needed.

I have a 2 bolt engine that needs a crank, a set of flat top pistons on rebuilt rods. and a set of 906 heads.

I will get a crank kit for 125.00
install the flat tops and rods. free
reseat the valves and put on new seals.
borrow the valve seal tool and cut them down.
I can pick up a vortec perfromer intake for 100.00
I also have a double roller chain new
have all the gaskets
just need a cam ,lifters,springs.

if it goes south in a year or 2, haven't really lost much, a 2 bolt block and a crank.

 

looking at the summit 1104, and 1788 and Lunati 10120410

 

What will be your final CR? That will be a big factor in which cam you can use. What is the altitude your going to be operating at?

 

engine is still in the car, but when I pull it I'll have to measure deck height, then head gasket and 906 's are 64 cc ?

correct ?

here are the pistons http://www.summitracing.com/parts/stl-h345np/overview/

 

With those 5cc pistons, stock deck, stock bore and the felpro .015 gasket you should be at 10.26:1 at sea level. If any of those change then your CR is going to be affected.
You have a plan on how to prepare the bore, and get it checked for taper and roundness?

There are a LOT of opinions on which cam to use.
Use this calculator to figure your static CR and your dynamic CR. With iron heads a max static of about 8.0:1 is recommended to avoid detonation.
http://www.jeepstrokers.com/calculator/
Another consideration is the max lift available with the 906 head. I read that it is about .475 inches stock. It can be increased by cutting down the valve guide. You may want to check and see what the max lift is for that head and make sure you don't exceed that with the cam/rocker combo you choose.
Of the three cams you selected the Lunati would keep you away from detonation and still give decent dynamic compression of 7.78:1.
If you stay with stock deck and .015 gasket this would give you a quench of .040". this is the number to shoot for to give good detonation resistance and still good piston clearance. I've read about guys with as little as .028" quench and such but that would be a bit close for me. .035" minimum maybe and .042" maximum would be my personal preference.
There are lots of different cams to choose from, look around and use the calculator I linked you to see what you come up with.

 

He says static here, but he actually means dynamic, just to clear up any confusion that this typo may have caused.

Also, how can altitude affect the static compression ratio? It's a displacement ratio, and air density shouldn't have any affect on displacement. 10.26:1 static compression ratio should still be 10.26:1 at sea-level, at the bottom of the ocean, or out in space. If I'm mistaken, please feel free to straighten me out, OK? I'm always willing to learn.

Also, this is the best article on Dynamic Compression I have ever read, and it has a pretty neat DCR calculator you can install on your PC. According to this article, it's important to keep your DCR above 7.5, to make good power over a wide rpm range, so the 7.78 that REELAV8R quotes sounds good.

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

Scott

 

Sorry bout that, yes dynamic of 8.0:1. Thanks Scott.

Your right in that altitude will not have an effect on static CR. Maybe it would be better stated as effective static CR. As altitude increases air density decreases which I'm sure you already know. This has a direct effect on dynamic CR and cylinder pressures. Since most people do not think in the terms of dynamic CR and only static CR the static CR can be raised without exceeding the dynamic CR limit. Therefore given the same cam you could raise the static CR to say 11.0:1 at 5000 ft and still only have a dynamic CR of 8.0:1 due to loss of air density.
Given his engine and a 280 duration cam on a 110 lsa with 64cc heads at sea level his static CR would be 10.03 and dynamic 7.94. Within limits of the iron heads and good power.

Same engine, same cam, but now 56cc heads and above sea level.
At sea level this would give us a 11.04 static CR and an 8.71 dynamic CR. Above the limits we are shooting for.
Move it to 3700 feet and due to loss of air density we now have an effective static CR of 10.3 and a dynamic CR of 7.97. Once again within limits.
I built my engine with this in mind. I live at 4000 feet and operate up to 8000 ft density altitude. By choosing the proper cam I can still develop good power at 8000 ft and not detonate even down to sea level running aluminum heads with pump fuel.

 

at sea level, unless it rains a lot then I am below sea level LOL

not sure how to determine head gasket thickness, but with a set of dial calipers I get .045 on the gasket part not cylinder ring.

couldn't get your chart to give me CR, but summit came up with 10.19, but a quench .065 or something like that.

 

Wow, I hate bashing on this engine build but I'm glad your asking questions and taking it all in

Back to vortex head, although they offer good power for an ok price, you still need to buy an intake. A pair of aluminum heads are about the same price.
Summit rebuild kits are good but I've found out recently the pistons sit far down in the bores. So the compression you expect is not what you get unless the block is deck.

You said it has a knock. So a crank grind is a must and you wanted flat top pistons. A block boil, bore, hone, cam bearings is about $500
Not including $160 crank grind

If it was me, and it will be me soon! I would find a 383 stroker kit. Most give you everything for the short block and I've seen them as cheap as $700. Balanced with bearing, rings and gaskets.
Add that to $500 in block work and $600 for heads .
You'll have a nasty street runner

Cheap version, pull motor, pull crank, have it ground, install with new bearings and run it until it blows !!!
Cost you bout $250 but a lot of work!!!
For not much gain

 

This is a function of deck height, not the rebuild kit. Unless the block is decked pistons in a stock block will always be around .020 down in the bore. Most aftermarket pistons assume the block is zero-decked with an .040 quench when they give CR numbers.

 

In order to use the jeep strokers calculator you need the specifics of your engine and it's components.
Bore: 4.00"
Stroke: 3.48"
head volume: 64cc
gasket bore: 4.1"
con rod length: 5.7"
gasket thickness: .045" ( you need to establish what this is the manufacturer tells you on the package or look it up on summit)
Then enter the cam specs your considering; ie
duration 280
LSA 110
degrees advance usually 4*
Then it will spit out the particulars.

There is a spot to also put in your altitude and it will automatically adjust the SCR and DCR.