Mild 400 build on a budget

[scot]

452's & 906's are both open chambered heads. You need a set of 915's or 516's.

 

[mgoblue9798]

452's & 906's are both open chambered heads. You need a set of 915's or 516's.

I am not the OP. He said he could not find any big block heads locally. I gave craigslist links for many sets, one of which was 516. The first two were 906 and 452, but were less than 250 and had already had valve jobs done. That motor is not going to make any power no matter what head he uses with pistons down .100 in the hole. My point is get a set of pistons, get the stuff balanced, and run a set of $200 heads for now if that is all he can afford. Head upgrade down the line is easy. Rebuilding the bottom end with those pistons is just throwing money out the window. Just my two cents.

 

[scot]

I agree 100%...you're not going to make a lot of power with the pistons .100 down in the hole, but some closed chambered heads would sure help and should bring compression up about a point. He did say it was a budget build and was just trying to help in the easiest way.

 

[Garys1969RR]

I once bought a pair of 906 heads for $50. Lapped the valves, cleaned em up, they ran great! You could pick up any of those heads, pull the valves and spin them in a drill putting emery cloth against the rusty spots. They will come out looking like new! Then lap the valves, clean em up and put them together. They will work fine in a street motor. Just make sure you clean them good, and oil the guides.

 

[91r/t]

Yea I am with alot of these guys, I would spend the cash on the pistons. If your gonna drive the hell out of it, you can spend a few hundred bucks more and make the car have a ton more power and fun to drive factor. If you could get the compression anywhere from 9.5-10:1 you would be doing alot better. That extra $500-$750 will pay out huge gains and make you a very happy customer in the end vs the low compression route. I know people make power on low compression, but compression builds power so I have always been a fan of hitting the 9.5:1 ratio to make decent power. I know there are the exceptions to the rule, but I also believe 87 octane is junk, especially in todays fuels. I wouldn't run that **** in my shittiest winter car. I love the guys who pump 87 into the newer Hemi's and say yea it runs fine.....when even Chrysler recommends 89 octane or more in them. The joys of modern timing....yea it runs but like ****

 

[400Magnum]

Ok. This is why I posted, to get feedback from guys that have the experience with these engines to know what makes them run best. Even though I am on a very limited budget, I want to do this right as much as possible the first time and not have to tear it apart again a few years later.

I appreciate the craigslist links and the effort you’re putting into this. I guess what I mean by trying to find them locally is a 20-30 minute drive, not an hour or more. I had seen the $175 heads before and considered them, but by the time I added up getting new hardened seats put in, and new guides, it was in the ballpark of $800. There is someone nearby that has 346 heads for $50, but they say they’re just cores. I could go look at them and see what they’re really like. If the seats and guides are within spec, I may just get them. They should have induction hardened seats, right?

But, it sounds like the thing I should focus on is getting the right pistons. So, that’s what I’m going to do. It really baffles me why no one makes a replacement piston for this engine that has zero deck height. I can find lightweight, fancy, high tech stroker pistons all day long, at pretty reasonable prices. Try to get an old school, cast piston at the correct compression height and weight matched to the originals, not going to happen. I was talking to a guy at Ross pistons about what I wanted, which is basically what you guys are saying I need to get, my only twist was to get them matched in weight to the originals. I basically need a 440 .060 oversize piston (that has a C.H. of 1.913) turned to .052 oversize instead. That puts me at 0.05 below deck which I thought would be decent enough. The weight of the cast piston could be adjusted easily to match the originals. His reply was they could do that, for about $900... Gee, thanks dude, I’ll get right back to you about that...

 

[91r/t]

Ok. This is why I posted, to get feedback from guys that have the experience with these engines to know what makes them run best. Even though I am on a very limited budget, I want to do this right as much as possible the first time and not have to tear it apart again a few years later.

I appreciate the craigslist links and the effort you’re putting into this. I guess what I mean by trying to find them locally is a 20-30 minute drive, not an hour or more. I had seen the $175 heads before and considered them, but by the time I added up getting new hardened seats put in, and new guides, it was in the ballpark of $800. There is someone nearby that has 346 heads for $50, but they say they’re just cores. I could go look at them and see what they’re really like. If the seats and guides are within spec, I may just get them. They should have induction hardened seats, right?

But, it sounds like the thing I should focus on is getting the right pistons. So, that’s what I’m going to do. It really baffles me why no one makes a replacement piston for this engine that has zero deck height. I can find lightweight, fancy, high tech stroker pistons all day long, at pretty reasonable prices. Try to get an old school, cast piston at the correct compression height and weight matched to the originals, not going to happen. I was talking to a guy at Ross pistons about what I wanted, which is basically what you guys are saying I need to get, my only twist was to get them matched in weight to the originals. I basically need a 440 .060 oversize piston (that has a C.H. of 1.913) turned to .052 oversize instead. That puts me at 0.05 below deck which I thought would be decent enough. The weight of the cast piston could be adjusted easily to match the originals. His reply was they could do that, for about $900... Gee, thanks dude, I’ll get right back to you about that...

I had the same issues when building my 360 small block. I wanted a piston that was in the hole a tad for compression reasons on my smaller chambered heads and they either had stock which was roughly .180" in the hole or zero or above deck height. Took some digging, but I found a set of Speed Pro's that did the job and put me .015" in the hole. My compression is 10.3:1, but I run 93 and it runs like a trooper! Glad I took the time to get the right pistons, as that and the heads are pretty much your whole combo to the correct build. One other thing I suggest is to check the deck height in a few spots to make sure it hasn't been decked before your time. If this is the case, it will throw your numbers off and screw your piston to deck clearance off. Ask me how I know.........I triple checked mine and still was a few thousandths off. Aggravating for sure when you cross your T's and dot your I's and you still find small errors here and there. But not checking at all could warrant a .010"-.030" difference and really throw your numbers off.

 

[400Magnum]

Good. Glad to hear persistence paid off for you. I just need to keep digging I guess. I could find pistons that were nearly the right weight, or put me close to the deck, but not both. There has to be someone out there that makes what I’m looking for. Years ago Dick Landy did a buildup on a 400 and modified some Federal Mogul forged pistons to get a nearly zero deck height. That buildup is what I was initially using as a guide for mine. Mild cam, 9.3-1, cast crank, nothing fancy, just a nice streetable engine that made decent power and would be stone cold reliable.

I’m just getting impatient because this has been on the back burner for 20 years and I still have a lot to do. Man, time sure does fly by when you aren’t paying attention.

 

[IQ52]

I too have looked into aftermarket heads to raise my C/R on my 400. From what I have read is the 75cc aluminum heads will raise compression about 1 point, but they will perform like the stock cast 452 heads power wise. Something about the aluminum not producing the heat to burn the fuel like the cast heads. I hope what I read is wrong, as I would like to go the 75cc head myself. Since $$$ is limited, I would look at the biggest bang per buck. I also remember you stating your heads are shot. I see your dilemma.

Hughes Engines talks about this in an article regarding cast iron vs aluminum heads. In short, at least the way I understand it, even though I’m raising my compression almost 1 point by using the 75cc heads, the aluminum dissipates the heat from combustion faster than cast iron, which reduces cylinder pressure to effectively lower the compression ratio by about 1 point. But, since I’m using a cam that builds significantly more cylinder pressure than the original cam, I should still be seeing a performance increase over what I started with. The bonus is that this head still flows better and is lighter than the 452’s, so I still come out somewhat ahead by getting the Eddy heads I think. For about the same money as what I’m going to pay just to get my stock heads usable, I can get the Eddy heads that flow better and are lighter, and they claim burn better, but I doubt I see any real benefit there. But if I ever have to submit to emission tests, that might help some then.

452 iron vs OOTB aftermarket aluminum. Hello guys, where do you come up with this lousy information? Any of the OOTB aftermarket aluminum heads will outflow a stock iron 452 head, thereby making more power.

And............

You have been feed a line of BS on the iron vs aluminum heads. That being, that the aluminum requires more compression to make the same horsepower. Here are two actual dyno tests, disproving that theory.

http://www.hotrod.com/articles/ccrp-0602-iron-versus-aluminum-cylinder-heads-test/

http://www.hotrod.com/articles/ccrp-0602-iron-versus-aluminum-cylinder-heads-test/

Now, anybody out there have any actual tests showing a different iron vs aluminum result? 'Cause I'd be glad to see them.

Now the disclaimer.......I would never run an aftermarket aluminum head OOTB. They all need to be inspected by a good head service before being run, all of them.

 

[451Mopar]

As your finding out custom pistons get expensive really fast. The KB-240 is about all there is off the shelf ($470), and it still is not zero deck (about 0.024")
The Brodix B1 B/S heads have about the smallest chambers for a big block. Normally 65cc, and can be milled even smaller. Problem is they are expensive. and use an offset intake rocker arm.

Really, if cost is a concern and the cylinders are good, just put the small cam in it, use a thin head gasket, and spend the $1,089.64-50.00 rebate that expires on the 28th ($1,039.64.pair of heads) on the 75cc Edelbrock E-street heads.
https://www.summitracing.com/parts/edl-5090/overview/
You will still need to spend the extra money on head bolts.
I think these will work with your small cam and stock rocker gear. Not sure on pushrod length, it would have to be checked.
That is only about 8.5:1 compression, but with the small cam and better heads run way better than it did before with the worn out heads.

If on a budget, I think starting to change pistons, or milling block/heads will just open a can of worms of having to spend extra in other areas like the balancing, or extra milling to fit the intake to the milled heads/block, and that is even if the block decks are square.
If your going to re-machine everything and but new pistons you may as well just start off with a stroker kit.

 

[400Magnum]

As far as flow, I’m in agreement and said that the aluminum heads will outflow the iron heads. I’m not sure why you think I’m saying something else.

As far as aluminum needing more compression to make the same power as iron, I’m getting my information from various places. Posts in other threads, and articles like the ones posted on Hughes Engines website. But I’ve also seen conflicting information, like the two links you just posted. I’m not a racer or experienced engine builder like most people here, which is why I thought I’d better post my question to get feedback so I don’t spend what little money I have on the wrong thing.

I’m all ears as far as what you guys have to say. I’ve also heard that any aftermarket head needs to be checked over before using. I’ve heard that the guides may not be straight to the seats, so the seats need redone. I’ve also heard about core shift. How exactly can you tell if the core did shift, and whether it’s going to cause a problem? There isn’t much you could do about that, is there? What do you do? Send the head back and get another one hoping for a better casting?

 

[451Mopar]

I don't recall what my cylinder head guy charged to check my trick flow heads, but it was not all that much. I also had then check the flow just to see if they flowed as advertised, so I would have to break out the costs from the bill.
Those heads checked out fine and did not need any work.

 

[400Magnum]

451, yes, that’s what my original plan was, to avoid the cost of having to get the crank balanced to new pistons. Again, when you start adding up the piecemeal prices it gets expensive. At that point I can spend a few bucks more and just buy a ready to go stroker kit that is better running than what I’m struggling to put together. Even though I don’t really want a stroker, it’s sure save me a lot of headaches.

But, all this may be for nothing. I just got a phone call and it looks like I may lose my job today. I’m getting too old and tired for this crap.

 

[IQ52]

I don't recall what my cylinder head guy charged to check my trick flow heads, but it was not all that much. I also had then check the flow just to see if they flowed as advertised, so I would have to break out the costs from the bill.
Those heads checked out fine and did not need any work.

You got lucky. Every big block Mopar Trick Flow head I have had through the shop had the valve guides too tight, and needed to be honed.

 

[451Mopar]

Sorry to hear about the job. I'm out of work too. That is why I have had time to be on here lately. I'm hoping to get a better job than my last one (being optimistic.) That last few times I changed jobs, it worked out good.
Not sure if my older age will make it harder to get a new job?

 

[400Magnum]

Sorry to hear that. My jobs have gotten worse and worse, and paid less and less. I’m just about as low as it gets now, part time and minimum wage, and now it’s a 50/50 chance I’ll lose it. My age definitely worked against me in my field, and the fact that the thing I’m good at is being outsourced overseas more and more.

Good luck, hope you find something soon that is to your liking.

 

[451Mopar]

You got lucky. Every big block Mopar Trick Flow head I have had through the shop had the valve guides too tight, and needed to be honed.

Not sure if you know him, but I have been working with Dave Sarno, SCH Racing Heads.
http://schracingheads.net/index.html

He did not say anything about the valve guides? I bought the heads a few years ago when they first came out if that makes a difference?

 

[Garys1969RR]

Oh darn! Thats not good news. As you are finding out, building these motors on a budget is very difficult. I have done it, and it's not easy. Some of the 383s had some decent pistons in them that had the piston .050 or less deck clearance. The 400 being a smog motor, wasn't as fortunate. You may be able to find some used 400 pistons on the site for a good price. Check there, enter 400 pistons in the search bar under parts for sale. Build a good bottom end with decent deck height, heads from C List, then change to a better head later on. I did that, started with my 906 heads, then later went to ported 915s I found on here, and gained a full second in the quarter mile. Well there's lots of ideas for you. If youre a little confused now, just stand by awhile. Lol

 

[400Magnum]

Yes, trying to do this on my budget is proving to be a real pain. Of all the engines Chrysler made, I think the 400 is the worst at finding good replacement pistons. If I were building a stroker, then it’s not a problem. Building a stock stroke engine is a different matter.

It makes sense to build a good short block first. I got side tracked by the excitement of saving $50 on a set of aluminum heads, making them about the same cost as getting my 452’s rebuilt. But, when compared to spending just over $1000, saving $50 isn’t all that much. After seeing the Craigslist links to some heads that are about an hour and a half drive away for way less money, maybe that’d be smarter for me right now. But right now I just have to wait and see whether I have a job by the end of the day.

 

[400Magnum]

Ok, just for the sake of continuing the thought. Of all the pistons I’ve looked at, the KB 240 comes pretty close to my needs. The compression distance is better at 1.908, which puts me at about 0.057” below deck. That’s pretty good, certainly better than 0.152” with the stock pistons.

The piston weight is low, but I can get heavier pins for about the same amount of money that it’d cost me to get the crank balanced, that would bring me up to just about 8 grams less than the piston/pin assemblies I just took out. So, that should work out good for balance, right? Measuring the weights of what I just took out, there’s a max difference in weight from heaviest to lightest of nearly 23 grams, with an average difference of almost 8 grams. So if I could put together a set that is more closely matched and comes in just a little lighter, that should work out okay, shouldn’t it??