Cylinder head selection
 

So I've got my heads off of my car right now and what started as a simple repair job has exploded into a "since I've got them off anyway..." situation. I want some advice as to what direction to take this thing.

My combo is 400 .030 over, cam 223/231 @.050 .465/.488 stock cast bottom end with crappy 411NP pistons (like 14cc valve reliefs and way down in the hole, they are awful). Edelbrock Performer intake with a 750 holley and small tube headers, th400 tranny with a 3000 stall converter and 3.23's in the rear. The old heads were stock #16 d-ports. I wasn't particularly happy with the power (ran 15.35 on my best run ever)

I'd like to pick cylinder heads to match the rest of the car. Was looking at either ported D-ports, e-heads or kauffman heads. My budget is relatively flexible but I don't want to spend $700 for an extra 5 horses, either.

Sorry for the long post, but I've read a bit on the subject and still can't tell what's the best route. Any thoughts, comments, ideas or suggestions from anyone are welcome and appreciated, thanks.

A motor with specs like yours, if it had 9.2 compression and if you heads currently are the big valve screw rocker stud #16 should make a easy 350 hp.

Rebuilt RAIII motors with far less cam lift and breathing thru stock late model exhaust manifolds have been dyno tested at 360 HP.

Its your rear gears that are killing your et.

If you want to keep your 3.23 gears I would suggest to get your current heads ported to flow 240 cfm@28 on the intake side and bring the exh side up to 180 cfm.

If you are willing to go up to 3.55 gears or a little better, than stepping up to the bigger port volume and better flowing D port type heads from KRE or Edelbrock would be the way to go.

Don`t forget that the greater power of better heads and stiffer gears will make traction and good 60 ft ETs a bigger problem!

What was your 60 time on that 15.35 run?

If you are into changing your heavy dished pistons outyou can at the same time go for much lighter and stronger rods.

with this change the motor will rev a bunch faster which will acount for a far better ET, but you will have to also get the motor rebalanced.

2.437 60 ft. went through at 92 mph. I'm not changing out those pistons until the motor needs an overhaul, but the gears could be a project for next year. So you don't think I'd get much more out of aluminum heads than ported iron, then?

It might pay for you first to get the car as is dyno tuned, as stock 69 350 HO birds with a 4 speed have run mid 13s with a far better 60 ft time that yours!

Which 16 D ports do you have? The `70 small valve, press in stud, or the `68 2.11 valve and screw in stud?

Thanks for the response, Steve. I suspect that the 60 ft is largely a result of the gear and tires, it was practically impossible to get a clean launch.

I've got the heads off now, and whatever I do to the car after it's back together I want to make the right head selection now so that I don't have to take them off again any time soon.

Has anyone tried the new d-port e-heads? They look interesting.

The '68 16's

I don`t think the heads are causing the mid 15 sec time slip. Even stock. Seems like with that cam, that car should be at least 2 sec. faster. Maybe the pistons are mostly the hard parts problem. But I think tuning is the real problem. How fast you want to go?

By the way, what car are you running? How heavy?

It's a '69 firebird, it is 3750 pounds with driver. I had it running perfectly on the street (until I started breaking valve springs but that's another story), though admittedly I'm kinda winging it on the tune. Ideally, I'll be running mid 13's or better.

I certainly haven't heard good things about those pistons, but I can't imagine that they'd hurt me very much.

What do you think?

Rebuild the shortboock with good flat tops and new rods, turn/polish crank and balance.... your heads are fine if they are machined well and have good valves/springs and guides... Im runnin 11.50s with stock 62's/cast intake and qjet on a 455 with a cam thats very similar to yours... in your case, the Horsepower is in the bottom end and in the tune... you should easily go high 12s-13.00s with traction and 3.55 gear... for what a set of heads cost, you can do everything i just mentioned and have a much more reliable setup, then switch heads down the road. JMO...good luck!

If you really wanna leave the shortblock "as-is" for now,here is how I'd approach this.

First thing first if you do opt to go the aftermarket head route,you'll for sure need to use the Kauffman D port heads and not the Edelbrock D port heads,and I'll explain why.

The E-D heads have the valve CL moved ever so slightly and that often poses a problem with "old school" pistons like you have with the valve reliefs in the "stock" location,now if you were using a more modern piston with the revised valve relief pockets,then you could use either head,but for now,the KRE D's are the best aftermarket head option with your current pistons.

Now that point is cleared up,the next order of business would be to choose the best head CC's,for your 400 cid combo.

That also affects the head gasket choices too in a way.

With the current piston situation you obviously have a few issues to try and deal with on this front.

So with the 74cc KRE D's and a standard head gasket and your poor deck clearance you'd be at like 9.2:1 or so (+/- like .25 CR),which for an aluminum head combo is pretty low no doubt.

A .027" thick cometic HG could bump that up like .25 point of CR to maybe 9.5:1 or so,but that's just mostly just amounts putting a band-aid on the real problem.

So my choice would be to opt for the 65cc KRE D's,along with using those .027" thick cometic head gaskets,as that combination of parts would both move the piston closer to the head for better overall quench (albeit down in the hole some) as well as reducing the chamber CC's to where the extra valve relief CC's become more or less a non-issue.

That would get you to like 10.30:1 CR,not @ all unheard of a CR for aluminum heads,matter of fact some would say that's an ideal CR for that sorta thing.

Then all you would need to do is pick out the porting level for those heads,here I'd likely just get the 260 cfm "entry level" ports for now,as that port level will still be a decent jump up from what you got now,and then later on they can be ported even further when you do end up going thru the shortblock.

Now I know what some are thinking,whats gonna happen when you rebuild later on and use some better pistons and maybe zero deck this thing,are'nt the 65cc chambers gonna be too small then?

Well they dont have to be,at least not so long as one is commited to keeping the stock 400 3.75" stroke that is,as the pistons I'd use for the next incarnation of this combo would be the #KB891 .040" over 14cc Icon dished forgings (which just so happens to be pretty close to the current valve relief cc's).

Then all you gotta do when you zero deck the next version is go back to using a .040" head gasket and the CR will be like 10.5:1.

And when you do eventually get around to doing the bottom end rebuild someday,I'd maybe bump the porting level up to the 290 cfm ports at that point as well.

So that's ^^^^ how I'd approach the whole aftermarket head option.

Next thing I'd wanna change would be the cam,for the time being I'd for sure opt for the Crower #60310 solid cam with some coolface lifters and not look back,the KRE D heads will already have good springs to run that sorta cam,so that part of the swap would be a no brainer to me.

And I'd swap that performer intake for a TII with that sorta combo seeing that it's using a Holley 750 cfm carb and such.

In the right car with proper tuning and decent traction,a combo like that should easily be a low 12 second combo,possibly even high 11's.

HP should be like 425 to 450 hp pretty easily.

And I'd leave the current gears & converter be for now too,they'll work just fine with this sorta combo.

JM2¢

Bret P.

Thanks everyone, I appreciate the advice. Due to the issues with the pistons, I've decided to just have my 16s fixed and save the aftermarket heads for later with a different shortblock some time.

Not anything against the KRE heads, I just get the feeling this bottom end is a bigger deal than I thought. I think I'd prefer to buy them once and get them ported and such at that time rather than have to mail them back later.

So,tell us just what's wrong with the #16 iron heads?

Odds are if those heads need any significant amount of work done to them,you'll end up with at least half of what a set of the aluminum heads cost into those iron heads (likely more than half),and then where are you at,pretty much back to square one right where you were before.

If those #16 heads still have stock vavles in them,that right there is a serious risk by itself,as it's not @ all unheard of to see the "high mileage" OE 2 pc. valves "pop the heads off" of them when aftermarket valve springs come into the picture.

So right there your looking at new valves,guides likely,valve springs,along with the corresponding machine work,and often that's just the tip of that iceberg.

Just dont say you were'nt warned that the cost for a basic "re-work" of some OE iron heads can end up being quite a bit more expensive than one originally thought it would be.

IMO the bottom end is only a "big deal" if you make it out to be such at this point in time.

Dont get me wrong here,I dont care for those "low end" pistons anymore than anyone else here does,but there are ways to deal with those sorta issues if you absolutely have to.

And you would only hafta send the KRE-D heads back later if you wanted them ported further,honestly you would'nt really need to do that if you found that you were infact prefectly happy with what you get from them @ the 260 cfm port level.

At the very minimum,if you opt to put it back together with the #16 iron heads,I'd be sure to use the .027" thick cometics head gaskets,now understand that they aint low budget head gaskets,but that's about the only way you can help that poor deck height issue besides doing some machine work to the shortblock.

In the end,the choice is yours,think about this long and hard,and be sure to get estimates and prices upfront and compare such between all the various options you're considering,as these days it's easy to be pennywise and pound foolish.

Nobody I know likes spending money twice for the same thing.

FWIW

Bret P.

I broke a couple of valve springs on the #16 heads, exhaust a few months ago and intake #7 most recently. When I put the cam in I was dumb and didn't have the machine work done to accommodate the extra lift, and apparently the valve guide and retainer were hitting or something.

I dropped them off at the machine shop today before I read your post, I'll get an estimate once they have them apart. One of the intake valves had a little chip in it; might have happened when the spring broke and it took the lifter and pushrod with it too. You've certainly convinced me to at least use the fancy head gasket no matter what route I go. I'm a little concerned about how long it will take to procure a set of the KRE heads, I've been calling since last week and haven't had them answer the phone yet.

Is it possible that the valve train issues were cause me to run slow at the track?

69 Birdboy,

Bret has offered you some very wise options, give them plenty of consideration. He has boat loads of experience and is only looking out for your best interest.

Tim john---

I talked to kauffman last week and they were going out of town, thay may be why you cant gat ahold of them. I am doing something similar to my 400. I have a 67 bird with a 400 WITH 6X heads. I found a set of kauffman heads on the PY classifieds that were new in the boxes but pre owned for a few hundred less than new ones, I am having them ported by a local head porter. I didnt know about the cometic gaskets though. I may opt for a pair of those! I think the rise in compression and flow will make a bigger difference than the pistons, you should try and find a set of the kauffman d ports.

Chris

Another person you might try is Chris of Hammertime Racing[authorized distributor of Kauffman products]

I don't have the time at the moment to catch up with what's been said... but fwiw, I had a lot of work done to a set of 6X heads. in the end, for another ~$500-600, I coulda had a set of KRE aluminum d-ports. and alot more power potential.

so, imo if you're going to have a lot of port work done to a set of iron heads, might as well just go ahead and opt for the aluminum heads.

I know I will next time.

:confused: Why not fix the issue you identified first and see what results?

It makes no sense to put a good set of heads on a "crappy" set of pistons if you're gonna run it hard... I bet i could do a 400 with TRW's, a set of 16's with new valves and springs, guides and a good valve grind... find the right cam, use a stock intake and i think i would outrun the alum head/cast piston setup.... or run right with it, and i bet my shortblock wouldnt have a huge hole in it after 100 passes shifting at 5800-6000rpms... my point is, its not that expensive to have a good valve grind/new valves/springs done to a set of 16's... you dont need portwork.... also, its not that expensive to build a trw shortblock... I guarantee you if you did that, and had a proper tune on it, it would run in the 12's easily with the gears and everything else you have, as long as you have traction.... i would rather sacrifice a few HP and have a reliable bottom end than have a set of heads you cant even really see the potential in because of your rpm capabilities... not tryin to ruffle any feathers, but, you have a ticking time bomb, unless you gonna shift below 5000 rpms... thus never seeing the benefit of a better flowing set of heads... JMO.... You're gonna lose alot of low end with 260cfm intake ports on a 400...even with 10 to 1 compression

I agree. He goes fast with stock stuff.

Hey Jimmy... yeah, it just seems like some are not lookin at the obvious...
If he's just gonna cruise it, you dont need alum heads... if he's gonna run it hard at all, you need better parts in the shortblock... IF he really wants aluminum heads, he would be much better off building a good shortblock and adding the heads at a later date... easy to make 400 hp with stock 16's/62's on a good flat top piston up to the top of the deck, balanced well and good ring seal, as long as the shop that does the valve grind knows whats happenin..... 750cfm carb and the right cam for the application, and good headers are about all you need to get it done... and some good tuning!

FYI: A set of TRW/FM 400 forgings are gonna be damn near as far down in the hole as his current pistons are (.020" down minimum for the forgings).

So that move really gets him little to nothing without also zero decking it.

The only significant difference there is the 8cc or so valve relief difference due to the cast pistons being the 8 valve relief items with the bevel.

And another thing is that pistons in general dont "make" more or less hp.

But better heads sure can make more hp.

As I understood this,the OP's whole line of thought here was to leave the shortblock together & in the car,and I'm not about to try and convince him it's the right or wrong path to take here,that's his choice and I respect that choice,thus I gave what I thought was the best advice for the situation as he had described it.

And I know I dont necessarily feel a cast bottom end is a ticking timebomb either really,JD ran his cast 8 relief bottom end pretty dang hard,and it lived,hell we all used to run cast bottom ends and most all of them took the merciless abuse in stride,did some of those fail,yep they sure did,but a whole lotta them lived long abuse filled lives too.

The OP clearly stated that he's commited to keeping the current bottom end for the time being regardless of whatever his head choice ends up being.

If ya'll wanna brow beat him into doing a full on rebuild here,by all means be my guest,I'll just let the fella make up his own mind,as I generally dont take part in that sorta thing.

I dunno about all of you out there,but those of us on super tight budgets just cant afford to spend money twice,so from time to time temporary compromises get made,and any risk associated with that short term choice gets taken into conisderation as well,but in the end you do what you gotta do.

Lets look at some of the basic parts costs for those #16 heads:
16 Ferrea SS. Valves = $200.00
Crower #68404-16 Valve Springs = $130.00
Valve Stem seals = $20.00
Crower #87048-16 Steel 7° Retainers = $65.00
Crower #86107-16 "Machined" 7° Valve Stem locks = $50.00

So that's $365.00 in parts right there,add new guides and the machine work for those and a "good" valve job and then add a bit more to surface the heads,and machine the guide bosses for good seals,yadda,yadda,yadda and there is no way he'll have those #16 heads "done right" for less than $500.00,honestly it probably will end up closer to $750.00 - $800.00 or so in my experience,and that's with ZERO porting,and any additonal porting would put the cost for his iron heads @ well over a grand for sure.

Anyone that says otherwise is either cutting corners on the parts being used,or the machine work costs,or is likely BS'ing you about some other item.

I know this,right now I got a set of well ported #96 heads on my all cast 455 bottom end,and back when I had those heads done (before the aftermarket aluminum heads became commonplace items) they cost me then as much as a set of KRE-D's would cost me today,so I know for sure that were I making that same sorta decision today,the choice would absolutely be a no-brainer.

Back when I had those #96 heads done it was $200.00 for the "good" valvejob and like $300.00 for the guides and hardened seats (parts included in that price),then add surfacing the heads for $50.00 and cut the guides for PC seals and slot for 1.65 rockers add another $75.00.

So labor for those heads were what,$625.00.
And that does'nt even include the porting or blocking the exhaust cross-overs.
That work added like another $800.00 in one fell swoop.

Here's what my #96 heads parts costs were:
Valves = $240.00
Crower #68405-16 springs = $80.00
Retainer & Keepers = $85.00
Spring shims = $33.00
Freeze plugs = $5.00
Heater hose fitting = $20.00

So that's what,another $463.00.

So if one really wants to dump a bunch of cash into some iron heads,you betcha it's easy enough to do that,especially if your naive enough to think otherwise.

Have I had iron heads done for less,yeah sure have,back when I kept the crap OE valves and just had the guides "knurled" and did the bare minimum needed to get them back together,re-used OE retainers,used the cheap "stamped" valve locks instead of the good "machined" valve locks,but even then the heads were almost always over $500.00 with "good" valve springs and such.

Recently I just had a set of FE 390 heads done awhile back for my brothers '68 Ranchero GT,nothing special done at all,basic valve job,surface the decks,fresh guides,had to get new valves,retainers,locks,springs,and those heads were over $800.00 out the door and again nothing special was really done to them.

So it does'nt really matter much what anyone here thinks it'll cost to get those #16 iron heads fixed,what really matters is what they guy your dealing with at the machine shop tells you it's gonna cost to get them fixed.

And again be fore-warned,dont dare assume your gonna "get off" cheap on a project like this,you should always assume it's gonna cost more than what you expect it to cost,as it almost always will cost more than what you thought it was gonna cost.

FWIW

Bret P.

The obvious point here is that the OP clearly stated in post #3 that the shortblock was not going to be torn into at this point in time.

That should be the end of any conversation on that topic.

Even if some of us feel it's a wise idea or not,it's his choice and you gotta respect that.

So that means were left with the discussion/debate about the heads.

Hence my comments and recommendations.

There is always more than one way to reach the same basic detination

2¢

Bret P.

I agree with you on pretty much everything you are sayin', but a cast piston will not stay in there near as long as a forged... ive got pistons(forged TRWs) in both my race cars from 1983 and 1985... very reliable pistons... i wouldnt even think to run a cast piston as hard as i do the forged ones... the rods dont bother me near as much as the pistons do.... i just hate to see him spend 2k on a set of alum heads, then, decide to run it up to 5600-5800 to get it to run, and have a piston failure and tear up the heads... it just seems that you'd want to invest in the rotating parts first if you are plannin on runnin it very hard on a regular basis... I just makin recommedations based on my experience... none of this stuff is cheap... you just got to decide what scares you and what doesnt... i wouldnt think that the cast pistons would hold up under the kind of horsepower that the alum heads have the potential to make... again, im not arguing, just stating my opinion

I hear you,,,they are flip sides of the same coin...

I've never seen a "true" cast piston failure tear up a head half as bad as a "popped" valve head will do,and that's especially true with a forged piston.

When you pop a head off one of those OE 2 pc. intake valves,it will typically imbed itself in the top of the "stronger" forged piston and just hammer the dog $#!t outta the head,and trust me it's not a pretty sight.

If that happens with a cast piston,then the piston typically shatters on impact and all the parts end up in the crankcase in short order and the head damage is far less severe.

So new valves are really not optional here no matter what heads get used.
And that's mandatory no matter what short block is under the chosen heads.

Typical "true" cast piston failures mostly involve cracking/breaking the skirts of the piston or breaking the ring lands,and rarely do those sorta cast piston failures ever result in any serious head damage or such,the only time that might damage a head is if the top ring land failed,and as such it broke loose into the chamber,but even then the head damage is minimal,as the piston material is aluminum,and thus it's much softer than the iron head is.

Most of the time when you see a fully scattered "cast" bottom end,99% of the time it was the cast rod that let loose first,and any cast piston failures were mostly collateral damage as the pistons were just an innocent bystander in all that resultant carnage.

Cast pistons usually dont cause those sorta failures,typically it's something else that's to blame.

Dont get me wrong,I prefer forged stuff too,but it's not always an item that's open for consideration,often it's use what you got or dont use it @ all,then what good is it doing?

FWIW

Bret P.

oh yeah... ive had valve decide to make 2 pieces instead of one...and i was travelling down the highway at 65mph when it happened... tore the sheet out of the cylinder and made shrapnel out of the cast piston that was in there... i wont use stock 2 pc valves in a new engine, whatsoever... No matter what he decides, i hope he has the best of luck with it... nothin worse than bad luck with these things...