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Discussion Starter · #1 ·
Ok, i have a 2 bolt main 1973 454 that i am going to have machine.

The heads are 353049 castings, which when i looked them up, were made: 1970-73 with an Open Chamber and 113.0cc.

I'm going to reuse the rods and crank. The heads will have new springs, guides, etc...

I always thought HIGHER COMPRESSION = MORE POWER. I'm going to go with some hyperutectic pistons, but what compression ratio should i shoot for? This is a pump gas motor.

What PISTONS with what CAMSHAFT should i use to get a good street/strip motor? (this is a buget power motor and i don't plan on buying a really $$$ cam. I'm planning on a new flat tappet hydrolic cam OR a USED solid roller cam.

I know this isn't a lot to go off of but i'm NEW making BIG BLOCK power.
 

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Discussion Starter · #3 ·
I'd love too get one, someday i want to build a BBC supercharged motor with a roller cam. But right now i gotta think $$$ unless someone wants to sell me there cam and lifters. I HATE absolutly HATE breaking in flat tappet hydraulic cams because i'm ALWAYS paronoid i'm going to whipe off the lobes.

Back to the issue at hand, unless one of you guys want to give me your BBC roller cam w/ lifters I need a cam piston set up thats going to work out with though heads (no money for better heads.. its sad, real sad, but i should be able to make it work with some assistance)

OBVIOUSLY i'm going with some roller rockers, roller chain or a GEAR KIT, and the dual plane performan intake with holley 700cfm DP carb, good ignition and headers. I just need some pistons and a cam to get me going. REMEMBER... i'm using STOCK rods and crank... so this motor is not going to be a HUGE BEAST. I just want something thats goina "MOVE!!"
 

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BIG BLOCK

Not being totally sure of the intended usage. Daily driver??? Weekend driver???

The first thing is that the 049 heads are 118cc as cast. Most will check closer to 120/121 cc. Depending where you got the info it's wrong. I have seen some sites that listed them at 113cc but it a miss print.....

I would get a piston that gets you in the 9.0 to 9.5 range for static compression. Then use a cam with duration in the 235/ 240 @.050 range 110/112 lsa. A edelbrock rpm air gap intake.... This should get you a combination that runs good and is easy on parts.....

If you can get a solid roller that sure would be the way to go. If not and you use a flat tappet hyd or solid cam don't get your self to up set over it going flat. Following a few break-in procedures and assembly tips will all but elimanate that from happening....

If you do go with the hypereutectic pistons pay real close attention to the top ring gap. These pistons work fine but got a bad rep for busting the top ring land because of improper gaps in the top ring.. I usually set mine .002 over the top of the recommended size.... They will not take any kind of detonation so make sure you have the tune right on it.....

Don't worry about using the stock crank and rods. The big chevy stuff is stout and will perform very well for you...

Keith
 

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You may want to zero deck the block. You can take off about .020" safely, which increases compression slightly as well. If you intend to use flat tops you will be limited to about 9.0:1 with the heads you have chosen to use. I have the 781's which are almost identical to the 049 castings. You may want to take .030" off the heads to gain a little more compression there. If you do use flat top pistons, it will limit your cam choices. do not stick in a long duration cam as it will kill your dynamic compression ratio and cylinder pressure. I am running the comp 268H which has a mildly lumpy idle, and just about all the duration you would want with a low compression big block.
 

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Run 9.5:1 compression and make sure that you have good quench. The 049 heads are pretty much the best flowing stock oval head you can get, so that is good. I would go with a performer RPM air gap intake manifold, and the comp XE274H cam (230 236 @.050, .552 .555 lift 1800-6000 RPM) with a 2500 stall or a XE284H (240 246 @ .050 .574 .578 lift 2300-6500 RPM) with a 3000 stall. Even with the heads in stock form, the motor should make a good 400-450 hp. Also, I would go with a set of KB hyper pistons. I think it is a good choice to go with the stock crank and rods since you are sticking with a 454, they will hold up to quite a bit. I would go the extra mile on the rod bolts though, they are usually what breaks. I would also consider a set of high ratio rockers.

Adam

These are the pistons I would get. If you have the money to get the heads milled a little bit so that all the chamber sizes are equal, and known, I think that would be a good idea. Also, these pistons are only 9.1:1 with a 119cc head, so going a little smaller on the chamber would help out in getting 9.5:1 compression.
This is the part numnber. (648-KB203.030) I would get these pistons, get the block 0 decked, get the heads milled to a 114cc chamber, and use as close to a .045 head gasket as you can get.

http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=267421&prmenbr=361
 

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Discussion Starter · #7 ·
what about these pistons??? I think its a typo and they are really supposed to be .210 dome, least thats what maddog said when i talked to them. But they get a 9.3:1 comp with my 119 heads. But since my heads are OPEN chamber, doesn't that mean the compresion will be less???? i'm confused on that.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33623&item=7933495674&rd=1

thoughs are the pistons from Maddog racing.. they are made by SPEED PRO.... any thoughts?
 

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The only real difference between open and closed chamber heads is the combustion chamber size. An open chamber head will be around 119cc and a closed chamber will be around 108cc. As far as the pistons that you found go, they look ok, I am just a little concerned about the discrepancy between the compression levels on the pistons you found and the ones out of jegs. According to the ones on ebay, with a +22cc dome you will have 9.3:1 compression with a 119cc chamber. According to JEGs, thier pistons have a -12cc dish, and that yeilds 9.1:1 compression with a 119cc chamber. I would think that a 34cc difference in dome size would have more than a .2:1 difference in compression. I would call jegs, or that company that you are looking at and present this situation to them and see what they say. I realize that there is a $100 difference between the 2 sets of pistons, which is a lot of money, but I would feel better buying the parts from jegs rather than some unknown company.

Good luck
Adam
 

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Discussion Starter · #9 ·
I called Maddog, they checked in the book and found they had an error on there auction. The pistons have only a .210" DOME on them and its at 9.2 with an STD bore and its at the 9.32 it my motor was to be bored .030 over. It seems like a good deal and i've ordered from them before, they check all the numbers in the book so i'm confident they fit now after varifying everything in the Speed Pro book. All i'm going to do now is see if it can be bores .020 or if it need to go to the .030 over and then order the pistons.

OTHER QUESTIONS:

FLOATER PISTONS OR PRESS FIT?

Is .020 just as good as .030 if it is a straight bore? Does It Matter? I want to only have to bore it out the minimum so if i ever have to bore it again, i'll have room to with out having to be at .060????

THANKS SO MUCH GUYS!
 

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Looks like you have been given some excellent advice here Personally I would just stick with a flat tapplet cam if i was you and just be very careful doing the breaki n, and save you self some money that you would have spend on the roller cam. Your planned combination sounds similar to what I have in my 79 chev 1/2, I'm using a 74 454 block with the 049 heads, a comp 268 cam 9.5:1 compression, edelbrock rpm intake, full length hooker headers and a 750 carb. Let me tell you that this is a very nice combo and feels very Strong surprisingly so especially with 3.08 gears out back. I will light up the tires at will and give you a good jolt back in your seat with a punch of the throttle even at highway speed.

Pressed in wrist pins will serve you just fine and yes a .020 overbore should be just fine unless you have some deeper scoring in the cylinder walls, very wise decission to keep boring to a minimum.
 

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Discussion Starter · #11 ·
The guy at maddog racing told me "floater" pistons are perferd over press fit. They cost the same, so it doesn't matter to me, i just want the better piston to get the biggest BANG for the BUCK.

Every small block i have built had the hydaulic flat tap cam, so i'm fine sticking with one... rollers better, but WAY over kill for their price in this preticular application.

Thanks for all your advice and information.
 
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