OPEN chamber vs CLOSED chambers? whats the difference?

[beastoakland]

Whats the difference btwen open and closed? Which has more power? If i were to get the heads rebuilt for a 1977 454 what will i need to do in order to get more low end torque and top end power?

[want-a-be]

What kind of vehicle are you going to run it in? How much street use/ track use? Are these going to be stock heads or after market?

Thanks, Don :cool:

WRCE

[beastoakland]

its going in a 1980 malibu wagon, only street use or get on the highway and blastoff to the next state only to stop for gas. It doesnt matter the type of heads. I want to know which direction should i go....

[want-a-be]

open chamber imo. the larger oval ports will do you just fine. put the larger valves in them. This would be done to the stock heads.

[Awesome Bill]

A nice set of semi open chambered heads work very well and are available. This will raise your compression from 8-1 to about 9-9.8/1. you can rebuild these and use them for a huge amount of power from what you will have. Nothing else to do but set up the springs for the cam you want and if you want, have them bowl ported and cleaned up, they make great power. Fully closed chambered heads would make way more power. They do have to be upgraded to unleaded fuel specs. So what ever you get, the closed chambered bathtub heads will make the best bang for the buck and you can get them on ebay cheap and have them done up right from someone like myself that still brings the dead back from the scrap iron grave. These will most likely put you over 10-1 compression. High Test Area but will make killer power.

[beastoakland]

Thanks wantabe, Bill and others......... What is the ballpark price to rebuild these heads so i wont get hammer at the shop...The reason i wont go with the heads i have on the 77 454 is because its peanut ports...To make sure im gonna check myself. Can i go with the aftermarket DART heads if so what would be best.....308cc??

[want-a-be]

You might get off cheaper with the rebuild of the stock heads....But, if you go with the Dart heads you'll be getting a new set of heads, with new guides in them already, with new seats, valves, springs, retainers, keepers, castings, and they should out preform the stock stuff. For not much more than rebuilding the old ones. If we were talking about small block stuff I could also add that they are more crack resistant then the stock ones by far.

If you have $500ish in rebuilding the old heads, then add in the cost of the old head cores, new valves, Springs, retainers, and keepers your almost up to the price of the new heads.

Sure I loose some money by guiding my customers this way, but they get the best bang for their buck in the long run. I'd go with the 308s and not look back. Better piece of mind also.


Thanks, Don :cool:

WCRE

[beastoakland]

thanks... i will purchase these heads....what else do i need to change cam,pushrods,rockers,lifters,and im changing intake and carb anyway.

[want-a-be]

What is your budget for this build? Then I/we can help more.

Thanks, Don :cool:

WCRE

[beastoakland]

well the machine shop said for a stock rebuild starts @ $1900+...... im not sure if its including heads...im gonna start out with a budget of $3200....i will spend money on parts that will make power i.e heads,cam,intake.

[want-a-be]

Whats your upper rpm limit on this build?

Don

WCRE

[beastoakland]

rpm limits?....thats when things that i am unfamiliar with....I want low end power as well as freeway too. I want to be able to pull off on someone who is trying to keep up.

[Awesome Bill]

We charge $1990.00 for the complete rebuild of a stock engine. This includes disassembly and marking, check the deck, align bore, bore .030 and torque plate hone it, new cam bearings, brass freeze plugs, mic and polish crank, press off old pistons, torque and check big and small ends of the rods. Recondition parts only as needed. Clean heads and valves, mic all parts, guides and valves are replaced if worn more than .001 each.

Engine Tech or PBM master kit is included with all parts brand new. Pistons, rings, cam, lifters, oil pump, main rod and cam bearings, brass plugs, oil pump, timing set, gasket set with rear seal all included.

This will put your short block back fresh and ready to handle up to 450 hp. To upgrade to the 107 or 100 cc closed chambered heads would be $999.00 for a complete rebuild of the heads with hardened seats for unleaded, stainless steel Race Flow Manley or Precision valves, new springs, locks and seals with valve springs set up for .550 lift. The heads get pressure checked and resurface on all surfaces that need it, rolled radius exhaust valve job with a 3 angle standard cut on the intake. If the heads need larger 2.19/1.88 valves, we bowl hog correctly for the larger valve and you up the price 200.00. So all in all, you can make a 454/450 with these heads with a ton of torque. The older oval ports will supply all the head you need.

If you purchase anything from Dart as far as heads, go with the 265 cc OVAL only. In your application, this will be the best for your combination.

So with a nice intake and carb, you could have a complete race ready fresh 454/450 that will hold its own with any Car for under $3500.00 dyno tested and tuned. Turn key deals are what you want. If you start out with a base price and every time you get a call its more money, you will be well over that with what I have quoted you. We run these style heads on drag engines all the time and they will supply all the power and more you will ever need. I would not use the peanut style head is possible.

[beastoakland]

Thats Awesome Bill...your price quote is my ball park....If it doesnt go well here i might have to ship my motor to u.

[Awesome Bill]

You would not be sorry @ all and would love the final result and power.