stuck on 400 heads
Ok guys im 19 and don't have to much experiance with engines but I am getting my hands wet right now with a sbc 400 it is stock with a little mild cam I have been told to run 350 heads on it but I don't want vortecs can sombody giveme some ideas I really only wanna use stock heads BC I don't have money for new ones im really just looking for a good set of heads that will work. Lookinf for casting #s any help will be appreciated
Avoid the 882 and 462624 heads. These are the lamest of the lame....
other stock heads...
If you are willing to do some hand porting to improve a stock head
it can work well for you.
Any all of the old camel back heads with the hi perf combustion chamber 492,041 040 186 292 461 462
113 aluminum 083 cast 5.7L TPI heads
920, 441 ,487
305HO 4416 624(305head)
all get better with porting. ( some need larger valves too)
The cam you got probabily can be improved on to make power on a 400.
why are you changing the heads in the first place? A mild 400 is fun to drive.I hope you already have the easy bolts ons? good manifold,carb,headers,good exhaust,decent car,good suspension and tires?
What do you want to accomplish?
So what other head choices do you got to work with?
What do you want to build?
Does the 400 SBC have a flat top piston or a dished piston now?
Be careful. With 64cc or 58cc heads, you could easily produce an 11:1 or higher static compression ratio, depending on piston crown configuration and piston deck height. Then you'd have to install a very aggressive cam to prevent detonation and you'd have no supporting components.
We bought as one lot number(a number of sets of heads) at auction a set of those aluminum Corvette 58cc heads.They almost don't have any chamber at all.It's like almost straight across.The OEM pistons for that are deep dish that I think where 18cc's.Those heads on a 400 would be crazy SCR's.And they don't port well given the thin castings they are.
Your best bet would to do the bolt on's as suggested and get a good three angle valve job with having the valve guides checked and new valve seals.
Don't be spooked by a small chamber head for your 400. Its likely it is a stock 400
with a stock dished 400 piston. This makes a 61-64cc head very usable on a 400.
See what you got available to work with. Then evaluate its suitability.
There are many good ways to skin this cat. A 58cc head is not necessarily the wrong head for you.
And can be modified.
Start by determining the pistons in your 400 ( flat top, dished) and what heads you got, can get, want to get.
and what your goals and budget are.
What fuel will you be using. Are you willing to use a good 92+ unleaded pump gas?
Again the 882 and 462624 heads are best avoided and not worth spending any money on.
If you are going to spend money fixing up a cylinder head find a better head to start with.
Don;t discount using a vortec head. Especially if there are good ones available (that are not cracked or fubared)
They make great budget power on 400's.
OK Smith, I'm gonna say this one last time and I'm outa here.....
ANYONE WHO TELLS YOU THAT YOU CAN BOLT 64cc OR 58cc HEADS ONTO YOUR MOTOR WITHOUT KNOWING THE PISTON CROWN CONFIGURATION OR PISTON DECK HEIGHT IS BEING TOTALLY IRRESPONSIBLE.
And don't forget to drill steam holes if you are going to use 350 or 305 heads.
The dished stock 400 pistons had a generous dish (the 400 often used a 24cc round dish piston stock), but by now there could be virtually anything in there for pistons. If the pistons are replacements for the original, you'll sometimes see a part number, or at least an oversize marking (like 30 or .030 for an 0.030" oversize, or similar). But unless the engine has been rebuilt there's a high chance the bores and pistons are worn.
If the original stock pistons are going to be reused, AND if the dish is 24cc, a 64cc chamber size will put the static compression ratio (SCR) at about 9.6:1 using a 0.040" quench. But the cam specs (intake closing point) and rod length needs to be used to find the dynamic compression ratio (DCR) to know if the combo will run on pump gas w/o detonating or not.
Which brings up the next point- you need to see if the rods are stock 400 rods (5.56" long) or if the engine was rebuilt using SBC 5.7" rods. Heck, you might get lucky and find a forged aftermarket crank and rods when you open it up, who knows?
But like has been said already- we need to know what it is you're trying to do along w/the specifics of the engine the way it sits (piston type, etc.).
Compression ratio calculators:
*Static compression ratio
*Dynamic compression calculator by Kelly
*Dynamic compression calculator by KB
After rereading my last post, I want to add (and repeat what others have said) that there's more to figuring the exact compression ratio than what I posted above- the deck height of the block needs to be known along w/the exact chamber size, gasket thickness and bore diameter and any overbore that may have been done. So like TI said- there's no way to know what the CR is going to be at this stage.
never seen tech post with so many caps? thanks for doing that,lol.and the post
I just recently posted multiple pictures of completed 305HO heads on a 350.
I do these heads for my self for $460. They are 400+hp capable. (full home hand port 1.94x 1.60 valves)
Check my posts. If the 400 has a dished piston ( as the stock OEM 400's had) the 305 heads 4416 castings (nominal 58 to 60cc)
can be a very good choice with some hand porting and some 1.94" valves.
Not the only head choice but one that works well for low $$$s.
(they end up about 61-62cc once all done with the larger valves.
A nice step up from crappy 882 or 462624 heads
when you got a set and not much money to burn.
The 083 head from a 350 tpi motor would be another good start point for a budget build. These port up nicely too.
if you got a flat top 400 piston look for some 920 or 441 castings and port them.
When it comes to using 305HO heads on a 350 or 400 SBC I know exactly what I am talking about , guy....
This can build a very very good high torque 375 to 400HP 400 SBC with the right supporting parts (cam intake carb headers) and head prep
using the 305HO heads on a otherwise good 400short block.
90% of the head prep, all the porting and mods can be done at home.
They don;t call these "The poor Man's race head", for nothing.
Like I said, first, determine what 400 piston you got and what cylinder heads you got or can get.
Work from there. There are lots of ways to skin this cat.
Gary if you don;t recognize to performance potential of a corvette "113" aluminum cylinder head TPI ZZ4 head casting you re the one who has no clue what you are talking about.
This is a excellent start pont for a budget build.. These heads are 450hp capable with correct porting. (2.00" x 1.56" LT4 valves
425HP is easy from these heads in home ported form and the stock valve sizes. Again the chamber ends up around 61-62cc when all done.
These aluminum heads have a 161cc port and end up around 175 to 180cc when ported and wll flow 245 to 260cfm intake and over 200cfm exhaust. If you can get a set for a affordable price, in good hape they are an excellent buy.
Excellent on a dished piston 400.
ALL THESE are a huge improvement over a 882 head, on a 400 SBC.
This is what a ported 305 cylinder head looks like, Gary.
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