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Rodgers25
Tribal Scout

10 Posts

Posted - 12 Dec 2015 :  3:59:36 PM  Show Profile  Reply with Quote
I have an original 77 bandit, the car was bought new by my father in 77 it was is first new car and it keeps it till today, they give it to me! So the engine need a rebuilt it's the original one with 78000k on it, so the best is behind it, I want to rebuild it to reach 350-400 HP. I have a 3k budjet so I don't know where to start.

400 6.6l w72 engine stock
6x 4 head


I got this set up twice, so the plan is to build the one that is off the car so
I have plenty of time to build it

Thanks for your advise!


Keven

Tub
Sitting Bull

172 Posts

Posted - 12 Dec 2015 :  9:24:12 PM  Show Profile  Reply with Quote
I've read that most '77 W72 engines used a casting number 500557 block. I wouldn't build a 500557 block. They have thinner, weak, main webs, which have resulted in lots of blown engines. Lots of guys will say the 557 blocks are good to at least 400hp. Some even brag about building high hp racing engines, using a 557 block and never had a single problem. But others have not been so lucky. So, if you feel lucky, then don't give it another thought.

I'd start the build with any 1970-79 400 block that doesn't have a casting number which ends with 557. The '71 thru early'75 #481988 400 blocks are some of the most common and desirable blocks. Also the XX481988 blocks, which were used in '78 & '79 W72 engines, are good blocks.

With only $3000 to spend, you may need to do some of the work yourself and cut a few corners. Here's an example of aprox what you can build for between $3000-$4000.

http://lenwilliamsautomachine.com/400_Long_Block.html

Most agree that it is a good idea to go with forged rods and pistons. The cheapest way to do this is with Speed-Pro L2262F pistons, and RPM 5140 rods.

http://www.ebay.com/itm/Speed-Pro-TRW-Pontiac-400-Forged-Coated-Skirt-Flat-Top-Piston-MOLY-Rings-Kit-30-/190855081106?hash=item2c6fd96c92:g:H-0AAMXQDK1RuHYs&vxp=mtr

http://www.racingpartsmaximum.com/sae5140stockrod-2.html

Some say just keep the cast rods, have them resized, and buy ARP bolts. But, since the 5140 forged rods are less than $300, at the time of this posting, they are stronger and probably will not add more than $100, if that much, to the price of the resized rods. It just don't make any sense to me, to spend $200 or more to use 40 year old cast rods. For $400, you can even buy H-beam rods, which are stronger than the 5140 rods. But, it's up to the guy spending the money. I built several low budget engines, using well used stock cast rods and bolts, with nothing done to 'em, at all. All my 455 bracket engines, but one, had cast rods. I put a rev limiter on 'em and never lost one. But, that was back before the cheap Chinese rods were available.

http://www.racingpartsmaximum.com/sae4340steelhbeam-2.html

Most also recommend going with one piece stainless valves, rather than the old original type stock valves, which have caused lots of blown engines. Some recommend going with 1.77 exhaust valves. But they are not needed for your power level.

Since the 6x heads produce under 9:1 compression, in stock form, a small Voodoo cam will increase dynamic compression, and up the power.

http://www.lunatipower.com/Product.aspx?id=1775

Having the block machined for near Zero deck height, will also increase compression.

One more item which will increase compression is thinner Cometic head gaskets. But, they cost about $100 each. If you have, say, .005 deck height, you could use some .036 x 4.160 Cometic gaskets, to increase compression and reduce the quench distance to .041. Many consider .040 or a little over a good quench distance to help prevent detonation.

http://www.jegs.com/i/Cometic-Gaskets/245/C5711-036/10002/-1?parentProductId=1288713


"...I want to rebuild it to reach 350-400 HP..."

The easiest way to hit 400hp is to stroke a 400 block. And you can use the 6x heads. As a bonus, you also get 500ft lbs of torque at just over 3000rpm.

http://www.jbp-pontiac.com/products/engines_assemblies/rotating_assemblies.html#461_467

http://lenwilliamsautomachine.com/455_Short_Block.html

http://www.sandovalperformance.com/#!product/prd12/2017678915/budget-series-shortblocks-starting-%40

Edited by - Tub on 13 Dec 2015 1:11:35 PM
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Bill Boyle
Horse Feathers (Charter Member)

USA
4797 Posts

Posted - 13 Dec 2015 :  10:06:12 AM  Show Profile  Visit Bill Boyle's Homepage  Reply with Quote
Whether its a '557 block or other 400 block, developing 350-400 hp will not be an issue. IMO, any of the 400 blocks can handle that performance level with room to spare.

No need to stroke the block to reach that performance level. However, the static compression of less than 9:1 will limit the pop in your combustion chamber.

Your 6x-4 head need to be milled .015, and treated to a valve job. One piece SS valves should be part of the deal along with new dual springs installed to match the camshaft lift. More than likely you will find an installed height around 1.700 to be about right. The heads could also stand some clean-up at a minimum and mild porting and gasket matching for improved street performance. Most of you money will be spent on heads, cam and related components. Another area will be the block with new forged flat top pistons and everything being properly balanced. A near zero deck is a good place to be.

With a limited budget, you can probably have the OEM rods refitted--again no need to spend extra money on aftermarket rods if they prove to be in good shape by your machinist. This is a budget rebuild.

Cam selection must be based on gearing and static compression and pressure. Duration around 220 on the intake with a lobe separation of 112 should be a good choice. It will provide enough vacuum to power your brakes.

Other areas to improve upon in conjunction with these parts is a good dual exhaust system. Since many years have passed since your car came off the lot, another exhaust system has probably been installed. Your engine is probably without the Cat, probably sporting 2" pipes running to 2 turbo type mufflers. The stock cast iron log manifold has to go. Headers are primo, but a nuisance to install, long branch type cast iron manifolds are available from RARE. Consider those. Also consider linking up with 2.5" pipes and top of the line turbo mufflers of today. Whether sitting in front of your axle or one crossflow mounted before your gas tank, flow will be greatly improved along with a strong menacing exhaust note.

Lots to consider. Select your components wisely and you won't run over your $3K budget (by much). Again developing hp between 350 and 400 isn't too difficult or costly today with an .030" over bored 400.

And btw, welcome to Pontiac Street Performance.

"Dedicated to keeping the classic Pontiac engine alive."

----
400 bored +.030, forged TRW pistons, ported 62 heads, Hedman headers, 2.5 SS dual exhaust X Pypes, Comp 276AH10 cam, Scorpion 1.65 RR, 850 Q-jet, stock intake & tuned HEI; original owner.
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cortcomp
Coyote

USA
5338 Posts

Posted - 13 Dec 2015 :  11:17:47 AM  Show Profile  Visit cortcomp's Homepage  Reply with Quote
I agree with what Bill said, but with decent aftermarket rods being under $300, i'd rather do that than re-do factory rods. Not that you'll be reving it that hard, it's just cheap insurance and it's not like if you get some extra cash later you can swap them right out. I generally spend money on projects based on how hard is it to get to/re do later? Inside engine? Burn cash. Heads? Well, you can swap aluminum on later if you ever wanted.

Just my 2c. Also, wonder about using some block fill on that block if you were worried? I'd hate to swap blocks on a matching numbers bandit car, especially if it's pretty stock and clean. I'd do everything i could with stock heads, intake, and block. MAYBE swap RA manifolds on, but Cliff mentioned a guy running like 10s with log manifolds, so who knows. You could do a lot of "trick" internal motor stuff to get a lot of power without stroking and aluminum heads and whatnot. Maybe a summit or lunati cam, or some of those guys run like XE cams with solid lifters and stock rockers and a tight valve lash?

Depends on what the "theme" of your project is i guess, and now original you want it to look. For me it'd be rods and pistons, likely overbore if it needs it, heads as bill mentioned, ignition and carb tuning, and a cam that added some but didn't change street manners.

Keep us posted!
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tjs44
Cochise

USA
413 Posts

Posted - 13 Dec 2015 :  2:12:27 PM  Show Profile  Reply with Quote
I agree with Bill on the block,with a stock stoke and better rotating assm it should be fine.I would for sure use aftermarket rods as the diff after new bolts and resizing wont be that far apart.Stock good quality cast pistons in that HP range should be OK also,just dont get the 8 valve relief units.RA manifolds are not that much diff from a good set of 4 tube headers and are IMO a no brainer for a street car.If a stick shift car the 2802 cam would be good.Tom
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Tub
Sitting Bull

172 Posts

Posted - 13 Dec 2015 :  3:32:33 PM  Show Profile  Reply with Quote
"...Stock good quality cast pistons in that HP range should be OK also,just dont get the 8 valve relief units..."


I'm just curious. Do you have some brand names and part numbers for some "good quality cast pistons" for a 400 Pontiac engine, that are a lot cheaper than the Speed-Pro L2262F forged pistons, but don't have 8 valve reliefs ?

I just did a Google search. I found Sealed Power, Silv-O-Lite, and Clevite 8-relief pistons. The only other 400 cast pistons I found, are the "Hypercast" KB pistons. But they cost quite a bit more than the SP L2262F forged pistons, which are $342 on Ebay.

Are there some cheap, good quality, cast pistons available for a 400, which I just can't find ?

Also have to inquire about the 2802 cam. The Summit site says this cam needs 9.5:1 or higher compression. I'm assuming that in order to get a 400, with 6x heads up to that much compression, would take 0 deck, thin Cometic head gaskets and quite a bit taken off the heads.??

http://www.summitracing.com/parts/sum-2802

I plugged in 400+.030, 90cc heads, 6.7cc valve reliefs, .036 x 4.16 Cometic gaskets, and .000 deck height. The Wallace calculator says the static CR would be 8.94.

http://www.wallaceracing.com/cr_test2.php

You'd have to cut the heads down to 83cc to get up to 9.5 CR. I've read that the 6x-4 heads came with 93-94cc chambers. So, can you safely cut enuff off of 'em to get down to 83cc ?

Also, is it worth the risk to run 9.5 CR, with the poor quality pump gas we have today ?

Hey, I'm no expert. I'm just asking. The Summit 2802 is similar to a 744 Pontiac cam, but with a bit more lift. I think all the 400 engines Pontiac put the 744 cam in, had well over 10:1 CR. I'm thinking that the only way I'd run a 2802 in a 400, with less than 9.5 CR is with Rhoads lifters, to reduce the duration at low rpm.

I think I'd feel safer with the 2801, if the CR was closer to 9:1. And for 8.5 or so, I'd still go with a Voodoo, like the 262. Almost every time I have recommended anything like a Summit cam or any of the old school Pontiac grinds, somebody has usually come on saying that those were old out of date stuff, and that you should use the modern grinds like the CC XE and Voodoo stuff. And if you recommend a HFT over on the PY site, some say everybody needs to switch to a roller cam, because of all the flat tappet cam failures, and in order to make the big power that everybody wants nowadays.

Hey, it's always the same. When it comes to cams, there are LOTS of difference of opinions. But, I reckin that's one of the things that keep these Pontiac threads interesting.


Edited by - Tub on 13 Dec 2015 3:48:05 PM
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Rodgers25
Tribal Scout

10 Posts

Posted - 13 Dec 2015 :  5:50:09 PM  Show Profile  Reply with Quote
Maybe 300hp will be ok, I just want more power with stock look, the car is in really good shape, all original parts, all are matching numbers, the car has never seen winter in 38 years,I'm in Canada so winter are tough, in this moment I have a replacement Engine in it, the same 400 as the original one, I remove the Original one (matching nunber)because it sound like something goes wrong with it but is still running. (my father guesses a bad crank bearing) So my plan is to rebuild the original one with a little more kick.

If it can help you some more info here:
Trans is a super t-10 4speeds manual 2,641st gear ratio
Rear diff gear is 2,41/1

And serously this engine stock only produce 200hp....?!?! thats quite low for a v-8

Edited by - Rodgers25 on 14 Dec 2015 5:54:39 PM
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tjs44
Cochise

USA
413 Posts

Posted - 13 Dec 2015 :  7:50:57 PM  Show Profile  Reply with Quote
I have only had one issue with 9.5 on our 91 pump gas and it was a 455 with a 2801 set straight up.It pumped 200 and we had to run a mix of race gas.I run cams with way more duration than a2802 with 9.5 iron heads with no issue at all.On the cast pistons I have not looked for any for a 400 for a long time so you could be right on the sealed powers being the deal.I have one car with KB hypers,one with Ross,another with Racetec and my 4 cyc with Egge casts.Tom
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Tub
Sitting Bull

172 Posts

Posted - 13 Dec 2015 :  9:46:48 PM  Show Profile  Reply with Quote
"..Rear dif gear is 2,40/1..."

If the car actually has 2.41 rear gears, then all you need is an almost bone stock engine rebuild, and switch to 3.42 gears and matching posi unit. You'll be really surprised at the difference.

A 4-speed needs at least 3.23 gears. IMO

So, I'd change out the gears FIRST. When you see how much difference they make, you may decide that you don't even want 400hp.

"...Maybe 300hp will be ok...

Some SP pistons and a Voodoo cam will probably get you real close to 300hp, without any other major improvements. If you decide to stay with the original valves, I'd stay with a factory Pontiac grind, like the 068. The Voodoo and the Summit 2802 will both need stronger valve springs, which will put more pressure on the valve stems. The 067 & 068 grinds only have just a hair over .400 lift, and do not have a steep ramp, like the Voodoo.

The Melling SPC-7 cam is an 068 grind. All the specs are shown on the Summit site. The best price I can find right now is from Auto Zone.

http://www.summitracing.com/parts/mel-spc-7

http://www.ebay.com/itm/261670110175?rmvSB=true

And the Summit lifters will save a few bucks.

http://www.summitracing.com/parts/sum-ht951/overview/make/pontiac

Edited by - Tub on 13 Dec 2015 10:24:02 PM
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tjs44
Cochise

USA
413 Posts

Posted - 14 Dec 2015 :  09:19:57 AM  Show Profile  Reply with Quote
What is your ST-10 first gear?They come in 3.42 to 2.43 first.I run a 3.42 first in my 62 tripower GP with a 2.68 rear and if you think about it it is almost like a 2.52 muncie with a 3.42 in the back when leaving a stop sign.Best of both worlds.Good accel from a stop and great freeway manners.Tom
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Rodgers25
Tribal Scout

10 Posts

Posted - 14 Dec 2015 :  12:21:53 PM  Show Profile  Reply with Quote
My spare St-10 has a 2.64 ratio, I don't know for the original one because the trans is in the car, so how I can know it? With trans VIN?

Edited by - Rodgers25 on 14 Dec 2015 5:55:16 PM
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tjs44
Cochise

USA
413 Posts

Posted - 14 Dec 2015 :  1:13:31 PM  Show Profile  Reply with Quote
If out you could tell by the rings on the input shaft.It is really like a compound low,with any kind of low rear gear you would have to shift within a few yards.I have a 3.27 first in my 69 bird with a 3.31 in the back and you just go a short distance and need to shift.Tom
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Tub
Sitting Bull

172 Posts

Posted - 14 Dec 2015 :  2:53:12 PM  Show Profile  Reply with Quote
"...It is really like a compound low,with any kind of low rear gear you would have to shift within a few yards..."


Yeah, that's sorta like the "granny low" 4-speeds in the 3/4, 1, & some 2-ton trucks, back in the old days. The shift pattern on the smaller truck knobs read L-1-2-3 instead of 1-2-3-4. But most of the 2-ton trucks had the 1-2-3-4 pattern knobs. You only used the Low if you were loaded. Otherwise, you started off in the 2nd lowest gear. Reverse could be on either side & either forward or backward, depending on which model you were driving. I drove many thousands of miles in them old trucks.

http://67-72chevytrucks.com/vboard/showpost.php?p=4599386&postcount=2

http://67-72chevytrucks.com/vboard/showpost.php?p=3723290&postcount=1

http://67-72chevytrucks.com/vboard/showpost.php?p=7085671&postcount=16

Edited by - Tub on 14 Dec 2015 3:52:21 PM
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Rodgers25
Tribal Scout

10 Posts

Posted - 14 Dec 2015 :  6:49:30 PM  Show Profile  Reply with Quote
What I understand:

First: Swap diff gear for 3.43 set
Crank: Stock
Connecting Rod: Stock
Piston: Sp piston
Cam: Melling SPC-7 cam is an 068 grind
Valve: Stock
Head: Stock
Intake: ?
Carb: ?
Headers: Something like that http://www.summitracing.com/int/parts/hed-28170/overview/make/pontiac
That give me oem look

Trans: My stock ST-10 2,64 with a rebuild kit for reliability


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tjs44
Cochise

USA
413 Posts

Posted - 14 Dec 2015 :  7:14:23 PM  Show Profile  Reply with Quote
I again would go to a inexpensive forged rod before spending money on new bolts and re-sizing.Good factory intake and QJ would be my choice.Tom
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Bill Boyle
Horse Feathers (Charter Member)

USA
4797 Posts

Posted - 14 Dec 2015 :  7:30:34 PM  Show Profile  Visit Bill Boyle's Homepage  Reply with Quote
Don't go with the 068 stock cam; designed for 10:1 CR. You won't make the 350 HP with it with so little static compression. Old grind I used with 6x-4 heads and new valves delivered around 315 hp based on computer inputs. That cam was a Comp Cam 270H. Never broke into the 13s with it--traction issues never resolved.

"Dedicated to keeping the classic Pontiac engine alive."

----
400 bored +.030, forged TRW pistons, ported 62 heads, Hedman headers, 2.5 SS dual exhaust X Pypes, Comp 276AH10 cam, Scorpion 1.65 RR, 850 Q-jet, stock intake & tuned HEI; original owner.
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Rodgers25
Tribal Scout

10 Posts

Posted - 16 Dec 2015 :  2:47:19 PM  Show Profile  Reply with Quote
I made a mistake, for diff ratio I told you what my father said to me, I count it by myself and the gear ratio are 3,23 posi. (both Wheel turn same direction And pignon made near 6,5 half turns by 2 Wheel spin)

I was told by someone that the ideal ratio transXdiff is around 10:
so if the car trans is really a 2,64 first gear ratio X 3,23)= 8.53

Then if I take 10/ by 2,64 = 3,78 so

Is 3,73 the good ratio for my car, is that mush difference with the 3.23?

Edited by - Rodgers25 on 16 Dec 2015 2:59:03 PM
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cortcomp
Coyote

USA
5338 Posts

Posted - 16 Dec 2015 :  3:39:41 PM  Show Profile  Visit cortcomp's Homepage  Reply with Quote
I have somewhat old-man tastes, i find my factory 3.23s almost too high (numerically) because i'm doing like 3k at 70mph. Others don't seem to mind having 4.11s and driving droning down the highway. So, gears and cam both have to kind of work together, but they both need to kind of work with what you want it to be like when you're driving it.
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phil400
Cochise

Canada
456 Posts

Posted - 22 Dec 2015 :  2:29:08 PM  Show Profile  Reply with Quote
I'd just stick with the 3.23s its a good all round gear.

78T/A 4-SPEED Marty blue 400/milled 6x-4's/268H,comp roller tip rockers/ performer Q-jet/RA manifolds 2.25" exhaust with x-pipe/ mine since '99 3rd & final owner as long as I'm alive
"sometimes I do what I want to do,rest of the time I do what I have to"
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tjs44
Cochise

USA
413 Posts

Posted - 22 Dec 2015 :  2:48:53 PM  Show Profile  Reply with Quote
JMO,anything lower than a 3.55(and even it can)sucks for a non OD street car.Tom
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Phil
The Great White Buffalo

USA
7222 Posts

Posted - 22 Dec 2015 :  4:35:13 PM  Show Profile  Reply with Quote
I agree. I can't stand my 3.42's these days unless I have the OD kicked in. Without OD, the best all around gear I can tolerate for combined driving is a 3.08.

Bowties are for Pee-wee Herman. "Chevy": even the name sounds cheap, but not as cheap as your Pontiac will be with an LS transplant.
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Brian R
Crazy Horse

USA
1672 Posts

Posted - 23 Dec 2015 :  11:39:36 AM  Show Profile  Reply with Quote
I agree. I have 3.55's with a non-overdrive tranny (turbo 400). Great around town but drive me nuts on the highway. If they ever go, I will go to at least a 3.23. If the tranny goes first, I will go with an OD tranny and leave the 3.55's.
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Rodgers25
Tribal Scout

10 Posts

Posted - 09 Jan 2016 :  07:57:07 AM  Show Profile  Reply with Quote
Here few update of my build.

The engine trouble is a bent push rod

After dissamsembly and mesuring it's gonna be a re-ring job,
Crank journal are good, Rod journal too, cyl bore too, wrist pin too, so i gonna re-ring piston (not sure if cast or moly coated should be used) and install new bearing. Stone in bore too

So basically the bottom gonna be stock.

I will go with:
-New oil pump
-New water pump
-All bearing (rod,main and cam)
-New cam (Comp cam #XE262Hcam) mine is square....
-New flatted lifters
-New stock style push rod
-New performer intake
-Carb? Not sure if im rebuilding one of my q-jet 17057263 or 17058276 or go with a new one( not sure wich to pick) Q-jet rebuil in part will cost arround 350$...
-New timming chain
-New distributor oem style one
-Headers, rm-2 Oversized 2 1/2" from R.A.R.E.

Head, stock 6x 4, i will grinding valve seat and it's gonna be all

Think it's all

I think its complet

Edited by - Rodgers25 on 09 Jan 2016 08:09:39 AM
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Blued and Painted
Chief PONTIAC

USA
3409 Posts

Posted - 09 Jan 2016 :  11:26:22 AM  Show Profile  Reply with Quote
The Base model performer intake will be a restriction. A factory iron intake will flow more.

RARE manifolds are most effective with camshafts with a lobe separation angle of 112 or greater per SD Performance.
-- http://www.sdperformance.com/moreTech.php?newsID=39 --

Send Mr. Cliff and e-mail with all vital engine and car specks for a cam recommendation. -- http://www.cliffshighperformance.com --


Bull Nose Formula/ 461/ Q-Jet/
TH400/ 3.08 8.5 / R44TS.

Edited by - Blued and Painted on 09 Jan 2016 11:32:04 AM
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BVR421
Sitting Bull

Bahamas
245 Posts

Posted - 24 Jan 2016 :  1:36:53 PM  Show Profile  Reply with Quote
Im not a bird guy but werent the W72 cars the 4sp, higher perf cars with rear disk brakes? 6x-4 heads instead of 6x-8?
whatever a w72 with only 78000 miles shouldnt need rebuilding unless it received less than adequate care and maintenance. (not unusual for old birds). Maybe a valve job, Summit 068 cam and lifters and a Quadrajet overhaul by a qualified tech
the 77-78 intakes are atrocious looking pancakes but Ive seen tests that they flow nearly as well as the earlier highrise.

ok this guy knows what he is talking about John Witke the w72 whiz
http://www.78ta.com/w72.php

Im only pushing this w72 stuff because it was the last hi-perf Pontiac v8 so its history we should know

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tjs44
Cochise

USA
413 Posts

Posted - 24 Jan 2016 :  4:37:13 PM  Show Profile  Reply with Quote
I would not buy a catalog cam for a pontiac.They are virtually all ground on a 110.Get something more on a 112-113.ANY comp cam lobes can be ordered custom for your application.Tom
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