Pontiac V8 H-Body

[NixVegaGT]

So I looked up some info about the 301. I'm so compulsive... ANyway, I was thinking why would you want to use such a massive engine at low CID? Why not just put in a 400 since they are the same size, right? Then I found a couple of references that put the 301 at 450ish pounds! That's pretty good! The references that I found said it was 451lbs. complete. If you could use some aluminum 400 heads or something it could even be lighter if they make such a thing.

I guess the pistons are pretty tough to find but you might be able to sub in some pistons from another engine. Like a 350 piston with the right deckheight or something. This is pretty hot!

[bugdewde]

I believe the 301 head is much different than a normal Poncho head. The 301 was built on the same assembly line as the 2.5L Iron Duke.
The 301 head has siamesed inner ports and don't flow mass quantities of air.... that's a huge grumble from the Pontiac fans.
Most Pontiac guys HATE the anemic 301.
Personally, I like it. They last a very long time(naturally aspirated).
Never would be a powerhouse, though ..... even turboed, it only put out around 200 hp.

The 79-81 Trans Am guys say the manual transmissioned 301 cars were quite peppy for the day..... not because of power but because of gearing and light weight.
The 400 Poncho motor infront of a manual trans(Super T-10...cast iron case) put out 220 hp/320 ft-lbs with a 2.43 first gear... with a rear gear of 3.23.
The 301(150-ish HP/240 ft-lbs) powered manuals had a much steeper 3.5-ish first gear (and a lighter aluminum case).... with a 3.08 rear.....

This steeper tranny gearing combined with the 100 lb lighter engine made the 301 powered T/A pretty fun to drive.
The 301 powered T/A even outperformed the Big engine T/As on the skid pads and in handling (even beating the Corvette ..... and Z-28, too). It was just short on Big power..... but still fun to drive.

Just like anything...... gearing will help a ton.
Swapping in the 3.23, 3.42 or even the 3.73 R&P from an earlier F-body would make up for some of the lost power but there's nothing like the torque of BIG CID.

Putting a much-hated 301 engine into a much-hated Vega/Astre..... is cool with me. All Pontiac rules. Straight line performance has never been a priority with me, though.

Here's some neat reading on the 301 in the '79 T/A... including all of it's powerplants.... Olds 403, Pontiac 400, Pontiac 301, Chevy 305..
http://www.iwaynet.net/~gl&lisk/transam.html (gotta click on the '79 link or the '79 at the bottom of the page... or even the turbo model in '80-'81....)

[res0o7eb]

Yeah, what Dwight said. Thanks, Dwight.

I have to applaud the Pontiac engineers for trying to keep their V-8 engine alive despite the emissions and fuel economy regulations that seemed to adversely affect them more than any other GM division. Here's a good story on the birth of the 301:
http://66.221.27.223/301birth.htm

Nicolas,
Yes, lighter weight was the reason I chose the 301. I am not chasing a horsepower number. I like the "idea" of a Pontiac V-8 in my Pontiac Astre more than anything else.

The 301 has a shorter deck height. So, using any other head - which will bolt on with no problem - would require a custom-built manifold (somebody did it - there was an article in HPP).
I am not sure if it is at all possible to mill an existing manifold and still be able to bolt it down to those heads. May have to elongate the holes. That is something I plan to investigate.

I have obtained another 301 (free!!!) - needs a rebuild - with the clam-shell motor mounts still attached.

I also have two flywheels. I read that the 301 is externally balanced, so I am not sure if I also need the harmonic balancer from a manual-equipped 301. That could be a problem.

Keep in mind his thread is about putting ANY Pontiac V-8 into ANY H-body.Please post your plans and tips.

[NixVegaGT]

That story of 301 is great! I'm just starting it. I found a really great site for 301 specs:

http://www.geocities.com/MotorCity/Boul ... tions.html

Here's a site with crank specs:

http://www.angelfire.com/fl4/pontiacdud ... ankpn.html

Pretty nice tables.

Having built... well not built but blueprinted and trial assembled a custom engine, I refuse to believe there is no way to build this engine a little. I wonder if you could turn down a 350 thin counterweight crank and get better balance. Then offset grind the rod journals from 2.25" to 2" reducing the stroke to 3.5", and the mains to 2.5". Then use Buick 215 5.66" rods. They came forged in stock configuration. Very plentiful. Then you could match those up with Ford 351W flattop pistons and have just about the right combo for the 9.143" deck height at 9.135".

Stroke: 3.5"/2 = 1.75"
Rod length: 5.66"
Comp. height: 1.719"

Total: 9.135"

That would be cool! Pontiac 350 with a 4" bore. Not a very good rod ratio. Pontiac really loved that 3.75" stroke though. That was the only way I could figure out how to destroke it a bit without needing a custom crank. BUT you would have a low-deck 350 that weighs almost as little as a Buick 350. All iron.

SO then I'm thinking you get some aluminum 400 heads and fab a custom intake. Maybe you could modify an existing intake. Not likely though. You could make an intake out of tube... the point is you could loose a few pounds that way. I'm not sure how much aluminum 400 heads weigh but it's got to be around half the weight. So 25 lbs. each? That saves another 40lbs. and your around 410ish lbs. If we are to believe the references of 451lbs. fully dressed non-turbo version.

[bugdewde]

I didn't know the heads would interchange.... That's great news.

Ditto on the tube intake.... I've seen custom sheetmetal intakes for the 215 engines, as well as air-cooled VW.... so why not. Heck, just add a couple plenums and some injectors.......

Now that's thinking outside the box Nic..... You're starting to scare me. I mean, a 400 lb Pontiac engine with nice, power producing aluminum heads with a large bore and shorter stroke....... hmmmm.... sounds like a high rev-ing Indian scream machine.
What about the weaker bottom end?
And here I was content to see a puny, anemic 301 in an Astre. More please!

[res0o7eb]

Putting a much-hated 301 engine into a much-hated Vega/Astre..... is cool with me. All Pontiac rules. Straight line performance has never been a priority with me, though.

DUDE!

And here I was content to see a puny, anemic 301 in an Astre. More please!

Dammit, now I gotta do this! You guys make me sick.

The HPP article also mentioned turning down a regular Pontiac crank for the 301 block similar to what you suggest, Nic. I think it was about 366 c.i. Must have been destroked or something - 4.00" bore and 3.75" stroke = 377 c.i.

Because I have CRS Syndrome, I now gotta go find the magazine to get the specs and share it with you guys so you all don't think I'm a liar or full of s**t.
Hmmm... If one has CRS(Can't Remember S**t) Syndrome, can one be full of s**t, too? Sorry, that's Philosopher Tom writing.

If I can find the HPP link, I'll post it, too.
(EDIT)Here's a link to a 301-dedicated thread in another forum where they mention the HPP article:
http://www.transamcountry.com/forum/vie ... c&start=40

Here's a site with crank specs:

http://www.angelfire.com/fl4/pontiacdud ... ankpn.html

Good info.
/* BEGIN RANT */
But, I HATE web sites with black backgrounds - there are soo many of these, especially automotive. I can't read them!
/* END RANT */

I found a couple of references that put the 301 at 450ish pounds! That's pretty good! The references that I found said it was 451lbs. complete.

HPP July 2007, pg. 47
Total Weight:
301 - 452 <-- You are correct, Nic.
350 - 579
400 - 675

301 Weight Loss Plan(350 weights):
Block - 126 (187) - 61
Crank - 42 (66) - 24
Head - 94 (110) - 16 <-- WOW. Crappy heads only save 16 pounds.
Intake - 24 (43) - 19

[NixVegaGT]

What about the weaker bottom end?

I'm thinking it wouldn't need to make a crap-load of power but 300hp would be nice. right? Even 275hp at 400ish pounds is pretty good. So maybe the bottom end wouldn't need to be super strong.

The references I read said the 301 engine was based on the 303 racing engine. So did they make the same weight savings tricks they used on the 301 block for the 303? That made some steep hp.

OK so I started seeing flaws in my combo. I think the big ends of the 215 rods aren't wide enough. Hmmm. OK so here's another idea:

Turn down a 350/400 thin counterweight crank. This time offset grind rod journals to 2.125" to get a 3.66" stroke. 3.66/2 = 1.83.

Hypereutectic Ford 302 HO pistons: 1.605" comp height
Chevy connecting rods: 5.7
Total deckheight: 9.135


OR grind rod journals to 2.1" shoot for a 3.6:

Hypereutectic Ford 302 HO pistons: 1.605" comp height
Chevy LT5 connecting rods: 5.74"
Total deckheight: 9.145

OOooo. That would be a hot combo. Damn I'm half tempted to build one of these just to do it!

[bugdewde]

It's guys like you that AWE me!
People who are: Enthusiastic, Knowledgeable, Motivated, Innovative, Capable and BRAVE are a rare breed.
Well, except for H-body fans. ha ha ha....

I wish I could contribute to this.... but, alas, the tech is already over my head and I'm merely a hopeful spectator. Sadly, I don't fall into the above category.... yeah, I'm no good.
I wish I was near you guys, I'd try to contribute in some way..... maybe sweeping the floors of the garage

Anxiously watching this for developments and wishing you guys luck in your endeavors if you attempt this.

As for the intake.......
Just thinking aloud here, could the stock intake be cut from front to back about an inch or so inboard of the head mounting surface(for good sealing and port surface matching) and then grafting in some runners(ala tuned ports) of various available materials used on today's cars such as carbon fiber, plastic, sheetmetal... whatever, .... enough to put a plenum or ..... (Hillborn-type injection..... ) heck, even a couple Weber downdraft carbs similar to the Hutton conversion for Cosworth engines.

Motor Mounts???? If balancing the reciprocating mass with the larger crank proves to be a problem, solid mounts would be frowned upon in my case. Wonder how the mounts would line up in an Astre body. Just thinking out loud again..... Wonder if they're similar to the Buick V6 (or 215) location?

If using a non-301 crank, the flywheel/bellhousing/trans issue should be just be a bolt on....... except for the starter/flywheel interface. Wonder if it's different?

Available Pontiac header flanges could be used to fab up some workable header tubes to clear the steering shaft, motor mounts, starter, etc.

Are the front timing covers or front crank seal areas compatible between block/crank/seal? Timing marks/tabs compatible? (not necessary but convenient) Nic is familar with this on the stroked 215/Rover/300 timing covers.
I think the timing chain/sprockets are compatible between the 301 350.

Hee hee hee..... this is cool. Way cool.
Just the relatively simple task of swapping in a stock 301 seems almost like a bolt in right now.

[res0o7eb]

Did you notice from the Pontiac crank table that the 55-56 V-8 engines had 2.50" dia. main journals?
The 301 has 2.50 mains! Should be a drop in.
[EDIT 11/3/2007: This has turned out to be incorrect, the web site is wrong. 301 cranks have 3.00" main journals.
And it is forged steel. Is that right?
Rod journal size is standard Pontiac 2.25" dia.

The stroke is 3.25, so that makes it a 327(326.7). COOL.
I'd call it a 326.
Availability is probably an issue, though.

Using the late cranks with the thin counterweights (350, 400) is probably more reasonable/feasable as Nic suggests.
The main journal dia is larger at 3.00".

Is it possible to "bore out" the main journals(?) in the 301 block from 2.50" to 3.00" using the main caps from a 350 or 400 block?
The crank would be a drop in.

[NixVegaGT]

I blew off the older cranks mostly because of availability and the differing snout length. I'm not sure why they got 1/2 longer... Could be because they added a harmonic balancer or something. When I first looked at the table I saw those 326 strokes and got pretty keyed up. Then I saw the unfamiliar size and snout length and changed direction. BUT the early 389 had the shorter snout so maybe there is not dimensional differences inside... Hmmm.

I wonder if they changed front covers. So on to rear hub. I noticed that the rear hub dia is the same as the old ones too. I figured that having the larger hub dia would extend the trans choices a bit. What do you guys think? I guess it might be possible to get an old engine somewhere and swap out the front cover stuff it the blocks are actually similar.

Dwight, you've got your new TransAM. It's a 6.6 right? Maybe you could snap some pix of the front cover/assy setup and Tom could compare it with 301 front covers. In the meantime we should see if we can find out any info about those older '50s engines to see if they are similar in architecture.

Here's somemore links I happened across:

http://www.pontiacpower.org/enginetheory.htm

WOW that's a bitchin' site. Lots of good motorhead info. check out the rod ratio for the 303. 2.49! HOLY SHIT!. That thing must have been a real screamer. Anyway that site is going to need some study.

That 317 was a pretty stout engine with the dual 4-barrels and 10.5 compression 285hp. not bad.

It looks like these Pontiac blocks are deep skirt. Am I right on that? If they are that's good news for us. It means we could fab a pretty simple lower block girdle to help strengthen it.

I can't find any references on block/crank differences yet. It's going to take some research. We have to build one of these! This is fun.

[res0o7eb]

I am not seeing a snout length dimension anywhere.
There is an NOS front cover on ebay - says it fits every Pontiac from 1969-1981, including 301.
http://cgi.ebay.com/ebaymotors/ws/eBayI ... 0159354471
I don't know the differences between early and late timing covers, yet, but I am sure the information is out there.
Here's another reference to a different cover:
http://www.professional-products.com/da ... ontiac.php

If you have any doubts about a Pontiac V-8 in an H-body, here's a link to a Pontiac T-1000 with a 301 in it.
http://www.casualrestorationsinc.com/ht ... 20Car.html

[barebonesracecars]

There are differences in the front covers, starting about 1969.

A 326 doesn't make a good performance starting point because of the small bore....too much valve shrouding.

You can put later heads on a 301, but with no rev potential, you can't really take advantage of them. A 301 would be a less desirable hi-po block than even a 326. A 301 is also a thin wall casting, so you won't be able to do much more than a clean-up overbore.

A 303 has problems, too....no low end; all top end. Part of that was the huge tunnel port heads they used. Then again, it was engineered for Trans Am racing, not street use.

301 cranks are also lighter and therefore weaker than 'standard' Pontiac cranks, which were plenty tough enough for several hundred HP.

Many very late '70's cranks are also somewhat lighter than the early cranks, and should also be avoided for performance.

Pontiac also had some odd c.i. sizes...the 326 may actually be closer to 327, but I don't recall for sure....seems to me they called it a '326' to be different than Chevrolet. The Pontiac 350 is actually 354 c.i.

Any way you look at it, the 400 and 455 blocks are the best stock Poncho blocks to build for the money. Bruce Fulper in CA claims to have built a streetable, pump gas 350 with 672 HP, and 421-428 blocks are also good (although harder to find). Yes, they weigh more, but the inherent low-end torque negates that, except in a nose-heavy car like ours when they are built for anything other than straight-line performance.

[bugdewde]

My 6.6 is actually a '76 5.7L Pontiac 350. I think is was originally a late '76 160 HP 2 barrel engine from the #s.
It is supposed to have a bigger cam and mildly worked 6x heads and an aftermarket distributor/ignition. I have ran the carb # but it's a quadrajet on a factory style intake.
I am really surprised with the low end torque of this engine.... and no knock.... at all.... I've tried.... even with 87 octane. Pulls unbelieveably well down low. It runs well on the high end, too. Stays real well with my buddy's 380 HP 360 in his '72 Duster if I keep the RPMs up.
I'll snap some pics of the front soon. I blew out both header gaskets and will probably swap out the clutch fan...... so front cover pics should be easy.

[barebonesracecars]

Those 6X heads are good ones. Look closely at the square boss just below the valve cover at the end of the head....see if it says 2, 4, or 8.

I'd have to look up the 2 again, but I believe they are fairly rare. A 4 is slightly higher compression than an 8.

6X heads are so numerous that they have become the commonly used performance head, and much cheaper than Ram Air, 670, and round port heads.

For years, people thought that Pontiac's exhaust ports were restrictive. There has been quite a bit of Pontiac research done over the last several years that it has been proven that it is the intakes that are restrictive. 6X's lend themselves to porting to make them flow nearly as well as RA IV's, as far as I have read.

The late 60's-early 70's stock 4 barrel intakes are hard to beat. Most aluminum intakes will not flow as well at street rpm's, until you get into Torquers and other single planes for high-rpm useage.

[NixVegaGT]

There are differences in the front covers, starting about 1969.

A 326 doesn't make a good performance starting point because of the small bore....too much valve shrouding.

You can put later heads on a 301, but with no rev potential, you can't really take advantage of them. A 301 would be a less desirable hi-po block than even a 326. A 301 is also a thin wall casting, so you won't be able to do much more than a clean-up overbore.

A 303 has problems, too....no low end; all top end. Part of that was the huge tunnel port heads they used. Then again, it was engineered for Trans Am racing, not street use.

301 cranks are also lighter and therefore weaker than 'standard' Pontiac cranks, which were plenty tough enough for several hundred HP.

Many very late '70's cranks are also somewhat lighter than the early cranks, and should also be avoided for performance.

Pontiac also had some odd c.i. sizes...the 326 may actually be closer to 327, but I don't recall for sure....seems to me they called it a '326' to be different than Chevrolet. The Pontiac 350 is actually 354 c.i.

Any way you look at it, the 400 and 455 blocks are the best stock Poncho blocks to build for the money. Bruce Fulper in CA claims to have built a streetable, pump gas 350 with 672 HP, and 421-428 blocks are also good (although harder to find). Yes, they weigh more, but the inherent low-end torque negates that, except in a nose-heavy car like ours when they are built for anything other than straight-line performance.

All good points, Reid. I totally agree about the crank that's gone for sure. For the block I suspect we'd be ok because we aren't talking about making 600hp here. More like 275 to 300. An early crank if we find one should do fine here. The shrouding with this block is eliminated by the 4" bore. It could be girdled to handle a little more power. Good point about the overbore. Maybe it'd take .020 ... Something to consider. Since they usually see pretty light duty it may be possible to get a honable version and go standard bore.

I wouldn't throw out weight savings as a valid concept here. We're talking about 175 lbs. less than the SBC. That's very significant. It would still be 80 lbs. front heavy but that goes a long way to having an all Pontiac V8 Astre with some cornering ability.

The Buick 350 is another example of an engine that's been tossed aside because the 455 is better. I don't agree, of course, and the Buick 350 is likely a bit more durable than this engine. For certain totally stock. But it's a LOT lighter as the lightest all-iron small block produced. I still think it's worth going through the process of researching it.

Racing use not likely... Road performance, could work well. We'll see.