Virgin engine builder/ "72" 400 cid

To everyone that reads this thanks for your time...

I have a 70 Lemans in the works and I got a line on a 72 400 engine that was sitting in a guys garage for $50. I wanted to do this by myself. I know I'm a hammer head, I just want the bragging rights,right?

Anyway, I have a 400 block with a balanced rotating assembly/ stock main caps, crank, rods, and four brow aluminum piston heads. Top end is 6x heads with a three angle valve job and an Edlebrock performer intake, stock water pump. MSD ignition system with a 6a box, and blaster 2 coil.  True roller timing chain. th400 manuel valve body, and 4.11:1 posi rear. mechanical holley 110 gph fuel pump.I want to run ten inch in the rear and eight inch up front.

My questions:

Carb: would a 650cc, do the job for a strong street engine with the occasional weekend at the track.

Cam: I am thinking of a 218-224 duration at .050 with an rpm range of 1300 to 5500. Hydraulic flat tappet. i.e. comp cams xe262h cam grind

torque converter: My understanding is that the xe262h runs a stock converter and is good on fuel but I am looking for something that will throw me back in the seat while not emptying my wallet. (everyone wants that, I know.)

oil pump: I have done ZERO research on this and all thoughts will be listened to with earnest.

push rods: the ones I pulled out of the block during tear down will not be reused. Any thoughts???

All in all, I want to have a fun car that runs solid with the least amount of worry and trouble. I would like to get my compression up around 9:1 to 9.25:1, but definatley not over that.

As of right now I just got the block back from the machine shop, so it's sitting on the stand oiled, and wrapped up till I can take the next step. IE buy the rebuild kit. Any help would be well a huge help... Thanks again  

Sounds like you're got all your parts ready for a decent build- do you have basic engine building tools like a piston ring compressor, piston ring installer, dead blow hammer, and a micrometer? BTW, since you're a virgin when it comes to engine building, what reference materials (other than the internet) do you have? Shop manuals from Motors, Chilton and Haynes will help, but enrolling in an engine rebuilding class at the local junior college will go a long way towards ensuring a successful rebuild.

Geno  

The 600 CFM carb should do you a good job in that RPM range.
Which 6X heads do you have, -8 or -4. If they are -8s and not been milled you will never see 9:1, -4s maybe close.
A little bit looser than stock converter would be OK but you'll have enough intial torgue you'll blow the rear tires off without a problem.
Oil pump the old reliable Melling M54D stock replacement should be fine with stock bearing specs.
I have the same cam you mention and is a good choise. The Comp push rods will be good also might consider the roller tip rockers. Hope you have and adjustable valve train. Good investment to go adjustable.
The biggest problem you will probably have is keep the thing running cool. High flow type water pump and performance stat with big radiator and clutch fan for starters and don't even think about not running a strode.  

Blackbird72: I am in the process of locating a bore mic. I have a 0" to 1" caliper but looking for a good starret bore mic. I have realized it to be more difficult than first anticipated. As for the rest of the aforementioned; yes. I have been tinkering for years, and finally took the plunge so to speak. I have a 455 at 4.18 bore (0.030 over) with a set of 6x that I was told has ripped three rearends apart but alas I fear I have some internal damage to it so I pulled it out of the Lemans. So here I find myself in a build. How you ask did I do damage... Long story short, going by the advise of someone I trusted, he told me to back off the pressure from the valves over winter. Then come the next summer I started to readjust the valves and magicaly the engine went PING and it wouldnt start again. LOL I found this engine mostly assembled for $50, I figured why not right? Also I found a repair manuel that was from pontiac for the 70 lemans gto tempest production line and THAT HAS BEEN A GODSEND.  

I found a link to an SCR-DCR calculator at projectpontiac.com. Sadly that has popped my 9:1 bubble. Lately I have been thinking about a set of edelbrock heads with an 87cc combustion chamber that would raise my SCR nicely but I really dont like putting aluminum on top of an iron block for mostly street. As for the -8vs -4, I am unsure. All I can tell you is the date codes for them are D215 which I believe translates to May 21 1975 (75 since they are 6X) and over the front (cylinders 1 or 2) GM3. My understanding is they are 101cc with a 3 angle valve
job.        
    As for the convertor, what would you recommend, a 1500 or something stronger?
         I will keep that in mind about the oil pump and probably do just that. Adjustable valve train? Do you mean mechanical and not hydraulic cam and lifters?
         As for the last part, I am already three steps ahead of you. I have a larger core rad with a tighter fin blade, flex fan, electric fan, and stock water pump, and or electric conversion pump motor that attachs to where the compressor would be.
    OK, I will reiterate. I am a virgin so there are many things I don't know... What is a "strode?"  

I believe he meant shroud, as in " fan shroud". Aluminum heads are fine on an iron block as long as you need them at your performance level, there is no durability issue on the street. Keep in mind you will need RA 4 style headers with Edelbrocks heads.
Adjustable valvetrain refers to converting to poly lock style nuts on the rockers as opposed to the "tighten down to factory specs, bottomed against the bottle neck studs" sty;e that our Pontiacs came with. Basically you are converting to the same style as Chevy uses so you can adjust lifter preload or valve clearance (hydraulic or solids, respectively).
Steve  
Trying to help... 'cause we don't all have to learn the hard way!

Oh... thanks barney, like I said before, I am still learning about the little inuendo's of building. I am definetly going to have to do some research there. Thanx again.

As for the aluminum vs iron, the only problem I am working with is "cc combustion chamber." The "101" is alot more than I am happy with and I have been thinking very hard about milling them down.  

pmg,
You don't need all of the more expensive engine building tools to put together a motor, but you do need to understand how it works and what needs to be checked and measured to build an engine correctly. I don't have a dial bore guage, but I can use a set of snap gauges and a micrometer proficiently to check cylinder bore diameters. I really don't recommend building your first engine solo, as there are plenty of steps you could miss and it could cost you. If you're not planning on taking shop courses at the local JC, at least find someone willing to help you (preferably someone who has built a Pontiac before). The internet is a great source of info, but it doesn't substitute for someone who has built a few Ponchos and can double- check your work.

Have you cc'd those heads to know they're 101ccs? That's the only way to be sure with Pontiac heads. 101ccs on a 406 will give you about 8:1, not bad for a street motor. You can mill those 6x's down to get 9:1 on a 400, but you'll have to cut .050 to get it- too much IMO. But they'll give you 9.5- 9.3:1 on a 400 stroker depending on your combustion chamber cc. I personally would keep the lower compression- get those 6x's ported and they will still make power and be more resistant to pinging and less sensitive to timing.

Geno  

Blackbird72:

     I have built small engine's before. I know that's not the same but I consider myself an intelligent person, but like you said, there are a few things that I don't know. I would rather learn about an engine in a garage rather than read a magazine. NOTHING PERSONAL TO THE HPP GUYS. (luv the mag.)
     I cataloged my tear down quite extensively and took a TON of notes, and pics. There are a few things that I still am getting the hang of... Like scr-dcr (didn't know about that until late), torque spec knowledge, wiring harness's (different story), knowing how to properly assemble heads (thanks to my machinist for doing that for me), and a few other items that I can't think of at the moment. Mostly my experience lies in golf cart engines, and commercial lawn mowers. As for building, a co-worker who worked on a pro drag team running hemi mopars about fifteen years back, has offered his services.

   "CC"ing the heads will be done when I get my next paycheck.
   As for stroking the engine, that is a big fat NO. I am sticking with the 3.75 crank. After much thought, and consideration, I have been thinking about 8:1. As long as I can beat on those frickin tuner cars. I'll be happy with this engine. I'm going to save the big one for the track.

    On a last note, I think that I will not get too overzealous with my camshaft, and carbuerator decision.

406 block
650 cfm carb
edelbrock performer intake
6X heads 3 angle valve job(no port or polish) history tells me my heads are 101 cc
comp cams: magnum pushrods
comp cams: hydraulic flat tappet XE262H and lifters
MSD pro billet with 6A box
Holley 110 gph mechanical fuel pump
Hooker full length header tuned at 1.75" primary and 3" collector set for D ports
true roller timing chain
reusing pistons and connecting rods/ pistons: four brow flat top aluminum
rings and seals (undecided)
Mellings M54D oil pump
reusing crank
reusing main caps
reusing stock harmonic balancer
reusing factory oil pan
Scat 166 tooth fly wheel
clevite bearings
Gaskets:
head gasket 0.021 compressed gasket thickness, 4.200 bore, 4.765 cylinder volume
extra large rad with an electric puller fan and flex fan ok ok I will use the darn shroud
Slightly over stock torque converter probably 1500 or 1800
TH400 manuel valve body (I got shifty ideas)
4.11:1 posi rear
AS FOR EVERYTHING ELSE IT WILL SLIGHTLY OVER STOCK. AFTER ALL MY NAME SAYS IT ALL!
this is not a wish list I already have 99% already  

For the most part I like your planned buildup, with two exceptions. First is the 4.11 gear, I think you would be far happier with less gear, say in the 3.42-3.55 range. Remember this isn't a small block Chevy, let the Pontiac torque do it's thing. Besides 4.11 gears with a th400 trans will be all tied up in knots at65 mph.
Second is the re-use of the pistons, unless of course they are already oversized and the bores check out ok, I would always recommend boring and new pistons. Aside from those points, sounds like fun.
Steve  
Trying to help... 'cause we don't all have to learn the hard way!

pmg,
I agree with Steve on rear end gearing- 4.11's are not necessary with a Pontiac unless it's a street/strip car. I run a 3.08 posi and my 'Bird with a 406 and ported no.48's runs 13.0x's- it also tops out around 145 mph, so it's safe to say it's freeway friendly too. I also like your parts list, but I no longer use stock cast rods in new builds as they're a liability in performance applications (lost a 406 when it threw a cast rod also) and new forged replacement rods (PPR, $250) are about the same cost as resized stockers.

IMO it doesn't make sense to build a fresh motor with a potential weak points like cast rods or stock 2-piece valves, but few build a Pontiac V-8 to get groceries- most will rev it to 5000 rpm to feel the power, and that's where 30+ year old reconditioned parts like cast rods and valves will fail. I don't sell parts but I do build engines and the last thing I want to see is one of my builds blown up, so I only use quality high performance parts. I build plenty of street motors too, for those I still use internals that won't fail if put to the test.

Geno  

4.11:1 came with the car, so I have to deal with it for the time being. I was really "hoping" that the bottom end would be strong enough but the both of you MAKE ALOT OF SENSE. I really don't want to pop my first engine.
    The crank stays, but I think I may go with the upgrades you mentioned. At first when I originally sat down to figure out my build I was going to use speed pro 4.15 bore flat top aluminum four brow forged, but the price hurt too much.
    By the by, do either of you recommend forged or cast aluminum?
    As for the rods, H-beam or I-beam? cast or forged?
    Please keep in mind this engine will once in a blue moon ever see 6000, as I will be more times than not short shifting at 5000 or lower.

    I did not want to go in this direction but to paraphrase...blowing a 406 sucks!  

pmg,
So I'm getting that you plan to use this 400 as a performance motor- it's good to be honest with yourself how you plan to use it, as a stock rebuild won't hold up long if it's being raced. The stock 3.75 crank is good to 600 hp as long as it's prepped properly (oil holes chamfered)- run ARP main studs and the 2-bolt caps will work fine (stock bolts work too, but the ARP studs are cheap insurance).

Run the lightest pistons and rods you can afford, as the stock cast pistons won't last in performance use (ring lands are junk). F-M Speed Pros are $370/set, forged K-B's are lighter, have floating pins and are $400/set- a no-brainer choice to me. And if you can't afford even Speed Pros, don't expect to compete with guys running forged K-B's, Probe SRS's, JE SRP's, BRC's, etc.- these are all forged lightweight racing-style slugs and make a huge difference in how any given motor will rev.

A decent piston that isn't expensive are KB Hypereutetics ($300/set)- they are cast, but a denser casting than the standand cast production piston and thus stronger. Hyper's have gotten a bad wrap because too many builders set the top ring gap too tight, resulting in the piston top 'popping off'- set them according to mfgr's specs and they run nice. GM puts them in most of their mid-line aftermarket crate engines and LS performance engines, so they work- don't listen to gossip from builders who can't read instructions.

The replacement 5140 forged rods will work fine for you application, but if you can upgrade go with either H or I-beam 4340 forged rods- either is good to 750 hp and will allow you to run at 5000+ rpm w/ no fear. All three of these rods also come w/ ARP bolts, so you can't loose running any of them.

Geno  

blackbird: Yeah I want a zippy ride, who doesn't? But please understand that I have a second engine that will be the big monster, should I ever win the lottery lol. I am expecting and hoping for 8:1 to 8.5:1 scr and between 350 to 400 hp with a 5500 max redline. This engine is for fun driving and learning.

I have been thinking about using a two dish valve relief to slightly raise cr to my comfort zone, and I have looked into the hyper's, but... I'm about one step away from saying F it.
    I think I just need to get the heck out of the garage for about a week or two! I guess we have all been there.

on a side note... I was playing around with some calculations and for some reason I keep coming up with 9.2:1 scr. WTF

pie divided by bore squared X stroke X 16.387 = cylinder volume

cylinder volume + compressed gasket cylinder volume = total volume

total volume + combustion chamber divided by combustion chamber = static compression ratio


4.15 X 4.15 X .785 X 3.75 X 16.387 = 830.80012

830.80012 + 4.757 = 835.567

835.567 + 101 divided by 101 = 9.27:1

Any thoughts? Because if my math is right, I am way too high for where I want to be @ 8.5:1  

Nothing wrong with trying to build a motor on a budget, but cast replacement type pistons won't hang with forged KB's, Probes, JE's, BRC's, or any of the other big-dog pistons. This is where all of the money spent on good pistons, rods, and quality machine work pays off- the guys who blow up in any race are usually the ones who ran stock parts or didn't upgrade. And don't kid yourself- everyone races sooner or later, just gotta make sure your motor will stay together when you buzz it.

Engine parts and machine work are alot more expensive now than they were 20 years ago- better to learn from other peoples' mistakes than making the same ones on your own. Use this engine to see what works instead of what doesn't. We all want that 650 hp $10k buildup- I've got another 400 waiting for the full-on stroker treatment too, but I'm building a 455 because it will be alot cheaper than a 462 stroker w/ roller cam, 4-bolt caps, KRE's, etc. Even if you have to wait and save it's much better to use the good parts instead in your rebuild of wishing you did when the cheap stuff takes a dump.

A 406 w/ 6x's will make 8-8.5:1- don't get twisted on the math. And as far as making 350-400 hp with a XE262, that I gotta see on a dyno- need a bit more cam to get there. Porting those 6x's will go a long way towards seeing 350+ hp. My 406 w/ported no.48's and a Crane 284H runs 13.0x's- about 400 hp according to some computer dynos, but IMO that's just more internet bench racing. The real proof is a dyno printout or a ET slip.

Geno