I'm not calling you a liar, I believe you that you stuffed parts that were optimized for a 467 into a 406 and saw shitty numbers out of the 406...you even admitted that the parts weren't meant for the 406 to run well...where I come from, that ain't a fair fight...you were making it sound like if all things were equal the 455 would put out 100hp more, but it was nowhere near an even playing field...you put together a 400 and a 455 with equal compression and cam grinds optimized for each motor and see if your numbers hold up...like I said, I could see it being a 50-60hp difference if all things were equal...hell, I could do the reverse and take parts from a 420hp 400 and choke a 455 down to 400hp with them if I wanted to say that I made a 400 with more power than a 455, but that wouldn't be fair...
I don't think anyone is calling anyone a liar, its just not a fair comparison. Lets face it, there are many ways to build an engine. You could build a high rev'r with 4:11s and a huge stall or you could build a low rev'r with tons of low end torque and 3:42 gears. The end of the track they could get there at the same time. If the torque motor is set up right and the traction is good, same as the high rev'ing engine. It all depends on the package. So whatever you build or built, thats all good, it's just the comparison of the two that you gained 100 more horses is not a fair comparison.
I'll admit, I was really hoping this guy had a secret to pulling 2hp per cubic inch out of a 455 to gain that 100hp difference in engine size...I would have been all ears...I still say Scotch's 601 Poncho is the baddest one on the street, that thing is insane...I should go look and see if he has any youtube videos of it...
There are bad forged rods in the early 60s and some good ones then on the 1973-74 455s but like I said, call Ace up, real cool guy. He knows his stuff. http://www.pacificperformanceracing.com/ Also Ken Keefer at http://www.angelfire.com/fl4/pontiacdude428/ Both of these guys are great guys. Stay away from BF.
What did I do? I'm here to learn, and these guys have some GREAT info...you admitted that the parts used on the 406 weren't proper for that motor and the 467 used them better, and also there was a HUGE compression difference, so how can you say it was even remotely a fair test between those two motors?...and yes, I do give Minnesota a bad name
Whatever, I'm a stupid kid and I don't know anything about anything...just ignore me and keep arguing your magical 92.2hp gains with 61 extra cubic inches...
Wow, just a quick glance through an old Hot Rod mag from October 2006 and I found a 466hp 484lb ft of torque 406 cubic inch Pontiac motor...and they were doing a budget build up, so they hadn't even gotten into testing a better cam and carb setup for the Edelbrock heads, so it could have been closer to 500hp had they matched everything...but apparently you can't get good numbers from small cubic inch Pontiacs...
You phrased your prior comments to suggest the 100 extra HP was due to the increase in cubes from 400 to 455. Not that an improperly built 400 was the test bed, with parts more conducive to 455 cubes Agreed!
I am new to this thread, I think. As for as a front mount, I would consider using a '60 or older timing cover. They are cast iron and have provisions for a mount. On GMC trucks with Pontiacs, they were used 1955-1959 On picking a block for a performance build, the 389 or 400 is the wisest choice. It has smaller mains which give more meterial in the bulkhead area plus the better oiling too and the bearings cost less than 428/455s. 389/400s are much more common making them much less expensive to purchase used. 455s are great motors, if you have one use it. if you don't, start with a 389/400. buy a stroker kit and end up with similar displacement as a 455 for less cost plus the above mentioned improvements. On the extra hole on the intake side and swaping manifolds. That extra 'hole' started in 1972 and was desigined to help keep oil temps down. Pontiac made other improvements in '72 to help cooling including larger water capacity in the heads. Because of this DIRECT intake interchage is 1965-1971 and 1972-1979. If you use a '71 older intake with '72 newer heads, you need to compensate for the intake leak on the right side. Steve www.pontiacheaven.org Hosting- 12th annual Pontiac Heaven April 8-11, 2010 Phoenix www.pontiacheaven.org 8th annual Nostalgic Show & Go! April 11, 2010 Phoenix www.nostalgicshowandgo.org
I have stated this above and that the 1972 intake is the only yeay that will fit both early and later heads without mods. I thought the extra exhaust crossover port hole was to separate the hot exhaust gasses from burning the oil in the heads?
Oops, just reread your post and you said to keep oil tems down which is the same as burning the oil. Damn, sometimes selective reading happenes even when you dont know it. Thanks Steve.
Can you elaborate on the extra hole? And how it affects oil temp? Also, I heard you wanted to talk to me by one of your crew guys. He said this after you saw my AWB 51 Ford w/421 in it at Bako a few yrs ago. I PM'd you on this a long time ago, but got no response. You ARE the guy with the Pontiac pwrd digger with some crazy wild welded up cyl heads?
There are hot exhaust gasses below the head oil valley. Only about 1/8" between the exhaust and the oil in the head makes the oil very hot! So it is just a buffer between the two. I'm not sure that it was that important but Pontiac tried alot of little things like that to better their original design over the years.
But Steve, the nice man from Kentucky said that 389's had outdated heads and 389/400's won't make decent power (ok, that was sarcasm in case you didn't notice)...I am now accepting all donations of 389's and 400's for those that want to throw them away so they can build a mega-high 500hp 455, hell, I'll even take the 326's and 350's too ...
I'm not picturing what you're saying here. Where's this extra hole? What's in it or passes through it?
Nothing is in it. They cast an extra bar that divides the exhaust crossover. So its just an empty space. If you wash your late model Pontiac engine, water can enter it which will boil out in a few seconds.
This is incorrect, the 72 intake has the same exhaust crossover issues that the 73-79 intakes do. The 72 intake is a nice intake to use though on a street engine with later heads like the 6X. That is because it is the only year intake with the later exhaust holes without EGR. Steve Hosting- 12th annual Pontiac Heaven April 8-11, 2010 Phoenix www.pontiacheaven.org 8th annual Nostalgic Show & Go! April 11, 2010 Phoenix www.nostalgicshowandgo.org
I thought I was clear about using a 389/400 based BLOCK as a wise choice for a performance build. You may or may not wish to use the heads. Also, almost none of the 455 heads Pontiac used are the best choice for a performance build because of their large chamber size. Steve Hosting- 12th annual Pontiac Heaven April 8-11, 2010 Phoenix www.pontiacheaven.org 8th annual Nostalgic Show & Go! April 11, 2010 Phoenix www.nostalgicshowandgo.org
Yes, I own and built the Pontiac Heaven Special AA/FD. We set the absolute Pontiac ET record at Bakersfield Hot Rod Reunion in 2006 at 6.77. The car has yet to make a full pass and has only run 200mph because of it. The record stood until last summer, my car is now #3 overall but still #1 using a stock production iron block. The heads are my own doing with considerable milling and welding. I milled 7 pounds of alum off of each head as an example. The head castings started as Wenzler Super Chiefs but are so different than as cast. Engine is based on a '59 or '60 389 with custom 6 bolt main billet lower end. I tune in the 92-96% nitro range and will go up from there. Back to your other question. All Pontiac production heads have a square exhaust crossover hole to warm the intake. Starting in '72, Pontiac added a second rectangular hole above it. It is more of a cave than a hole going anywhere. I read in an engineering report years ago the Pontiac did that in a effort to separate the oil from the valvetrain from the hot exhaust crossover beneath it. The idea was to create an air gap. As a result, if you use a '65-'71 intake on '72 and later heads, you will end up with an exhaust leak on the passenger side of the take where it bolts to the head. One would need to block off or fill in that hole to solve the problem. That is why 72 intake are desireable with , say , 6x heads. That is what I am building now for the tow car for my AA/Fueler. It is a '61 Catalina Safari with 455, 6X heads and '72 intake with a 700r4 behind it with 2.69 POSI. I have not been able to run my AA/Fueler in some time due to funding. the car is ready to go, except form an expired chassis tag and some misc. We may be able to run at the March Meet and I have scheduled a best of 3 match race my April 11 "Nostalgic Show & Go!" in Phoenix against a chev powerwed AA/Fueler. Steve Hosting- 12th annual Pontiac Heaven April 8-11, 2010 Phoenix www.pontiacheaven.org 8th annual Nostalgic Show & Go! April 11, 2010 Phoenix www.nostalgicshowandgo.org Steve
Thanks guys. How deep or far does the hole go towards the exh. side of the head? I mean, since the bulk of the oil coming off the rockers is gonna be at the bottom gasket rail, rather than the top, where you guys say the hole starts. Almost a moot point if the hole's shallow, if it's design was to keep heat away from the oil
Steve, nevermind my sarcasm, I was poking fun at the guy from the previous page that was trying to prove you wrong with his biased numbers (he said you get an extra 100hp from a 455)...it was just a joke...on another note, I wish I hadn't ever sold my '59 389, it would have made a bitchin A roadster motor built up as a hot 2bbl motor in a light car...
the hole is not very deep, I would guess 3/4". I understand your point and it may seem logical but Pontiac engineers had access to about anything and tested more than probably all of us put together. As a result, the mid/late late Pontiac heads ( 5c, 6x and some of the 4x ) are among the best choice for a street build as they have the large water jackets, screw in studs, proper chamber size, bign intake valve, all the exhaust bolt holes, etc, etc, etc. Steve Hosting- 12th annual Pontiac Heaven April 8-11, 2010 Phoenix www.pontiacheaven.org 8th annual Nostalgic Show & Go! April 11, 2010 Phoenix www.nostalgicshowandgo.org
Quote: <TABLE border=0 cellSpacing=0 cellPadding=6 width="100%"><TBODY><TR><TD style="BORDER-BOTTOM: 1px inset; BORDER-LEFT: 1px inset; BORDER-TOP: 1px inset; BORDER-RIGHT: 1px inset" class=alt2>Originally Posted by The Rabid Whippet I have stated this above and that the 1972 intake is the only year that will fit both early and later heads without mods. I thought the extra exhaust crossover port hole was to separate the hot exhaust gasses from burning the oil in the heads? </TD></TR></TBODY></TABLE> Steve I am not following you as you say this is incorrect yet then say the same thing I just wrote. I am talking early heads as 1965-1972 and then the later 1973-1978/79 with the opening. Thats why I say the 1972 is desireable as it fits both heads 1965-1979 without modifying the exhaust crossover. We weren't talking about the earlier 1964 and older heads.
If you click on "quote", your reply will be "attached" (like this is to yours) to the post in mind, and there won't be any mis-understanding who you're replying to
Mid to late 70s. They were built with a better port and higher/flatter floor. 4Xs 1973-1974 5Cs 1975 6Xs 1976-1979. You also have to look for the secondary number as you dont want 4X from a 455 unless you have a blower/turbo etc. These heads are all suited for a 455 with about 9-1 compression. On a 400, they are about 8-1
I vaguely remember the heads of that era having HUGE combustion chambers. Almost double of what the late 60's heads were. Horrible for compression/performance (for the 400 anyway). I do remember they had pretty big valves. Pretty funny, considering that era Pontiac couldn't pull steam off a fucking hot dog. A real waste of big valves. Anyway, I had a 400 in a 60 Pontiac that was fucking gutless, to find out it had some of that era head on it. When I found out the chamber size, I figured with the one size fits all chamber 8 valve relief pistons I was working with a high 7-1 or very low 8-1 compression. Mystery solved, but it was still a pooch with those heads.
My '76 400 2bbl motor with 6X heads has 7.6:1 compression...I feel your pain...on the up side, it's the perfect combo for throwing a blower on it, so, problem solved...I've also got a pair of '71 350 "21" heads set aside in case I stay with naturally aspirated, they should bump me up to 9:1 or higher depending on what pistons I use...
The Jalopy Journal
