zpi28
Well-known member
Guy next door has a complete 455 motor and trans out of a 72 Pontiac fullsize. He said he would sell it, but just wanting to know if they are good motors. Maybe get this for my 53 Chevy truck.
Guy next door has a complete 455 motor and trans out of a 72 Pontiac fullsize. He said he would sell it, but just wanting to know if they are good motors. Maybe get this for my 53 Chevy truck.
hey sgtpontiac isn't the passenger bank ahead of the drivers bank on pontiac motors? the reason i ask is i sold a 400 years ago that i had numbered the rods starting at the front number 1, but the guy who brought it from me told me that the frist rod was #2.
if i remember correctly the cylinders are numbered the same as chevy v8 but the firing order is reversed instead of 18436572 i think it is 27563481 if this is as i recall then your starting your firing order with the #2 cylinder i could see how that could confuse #1 with #2
hey sgtpontiac isn't the passenger bank ahead of the drivers bank on pontiac motors? the reason i ask is i sold a 400 years ago that i had numbered the rods starting at the front number 1, but the guy who brought it from me told me that the frist rod was #2.
if i remember correctly the cylinders are numbered the same as chevy v8 but the firing order is reversed instead of 18436572 i think it is 27563481 if this is as i recall then your starting your firing order with the #2 cylinder i could see how that could confuse #1 with #2
pontiacs have 4 head bolts per cylinder instead of 5 and i have had a head gasket go out but it burned out between the cylinders idk how the head bolt placement had anything to do with that
ive had a few really hot running 400's. i bought a 455 once and test drove it but never got around to building it.
for extended rpm's 7,000 and over it's recommended you build a 400 block
they sell 400 cranks with 455 stroke and you bore the 400 something like.060 over and use std. 455 pistons to get the smaller 400 mains.
p400 mains are 3" and the p455 runs a 3.25 main
weak link in the pontiac reciprocating assembly are the rod bolts
they stretch if over revved and cause the bearigns to spin then throw the rod
arp rod bolts and getting the rods magnafluxed and rebuilt will prevent throwing a rod up to 6,000 rpm they say if your going higher than that to use aftermarket forged rods.
the pontiac nodular crank and the arma-steel cranks are pretty tough.
there is an opening down the middle of the galley between the lifter bores requiring a lifter bore brace if using a radical solid lifter or roller cam
the pontiac ram air 4 or RAIV hydraulic #014 cam with the hp rockers runs on a 113.5 degree lobe centers and 302 degrees adv duration and .520 lift. its actually bigger than many of the aftermarket pontiac cams it's my favorite. powerband is from 2,000 to 6,000
driving it fells like you pick up maybe 50-75hp between 1,500 and 2,000 rpm you definitely know when you hit the powerband and that cam doesnt drop power till somewhere around 5500 to 6000rpm with a stock 4bbl intake and quadrajet
expect probably 450 horsepower and 500 ft-lbs with a performer rpm cam and if you have an overdrive or highway gears...almost everyone who's ever had a pontiac 400 could get 18mpg on the highway with it.
you could pickup a cheap set of 400 heads with the big valves to pick up half a point of compression on a 455.
whatever you do...dont bolt in the oil pump with an ordinary bolt and there's a funky plug or something somewhere in the oil gallys you need to do something with
you have behind the waterpump block off plate 2 short removable transfer tubes with donut seals to bring the water pump water from the pump to the front of the block. the pump sucks in the center from behind that plate so the space between the plate and the timing cover is the return water to the radiator.
the first design 389 had 1 transfer tube.
it pushed water into the passenger bank, up through the passenger head, accross the intake, and down through the drivers head intot he drivers side of the block then back to the radiator...
the second design put into production around 1968 69? pushes water into both sides of the block up through both heads... then through the intake back to the radiator.
if you have an older engine 1967 and older you can install the newer timing cover, water pump and blockoff plate and transfer tubes to get the more efficient coolant flow.
I had a perfect condition 67 389 timing cover i wasn't going to use and had 4or5 gto guys biddign for it on ebay. i got 60 bucks for it because the casting numbers were correct so if you have one in good shape no corrosion dont chuck it for aluminum.
i found out the hard way that if you are going to use headers with a lakewood bellhousing on a Pontiac you have to relocate your oil filter pad
the pontiac v8 is slightly bigger than a 454 chevy but it is lighter
there are aftermarket blocks and parts to build a racing pontiac around 600 cubes or more
Micky Thompson used to sell hemi heads for pontiacs
Micky's naturally aspirated 389 Pontiacs cleaned up at the track against the 392 hemi
The dodge boys couldn't touch him until the 426 came along
It used to be a popular Thunderbird swap to change out a 292 or 312 ford with a 389 Pontiac and alot of pontiac mills have gone into trucks.
before the GMC v6 came along v8 GMC trucks got the 370 pontiac from the factory and (if you can find a set) those GMC valve covers should be able to fit your 455.
There is a cheap gm to ford conversion listed on Novak adapters website.
you buy their throwout bearing and take a gm CAR bellhousing...
take the front bearing retainer off your ford manual tranny have it shortened and turned down to fit a gm throwout bearing...
and turned to fit into the bellhousing...
shorten the crank bearing nipple on the end of the input shaft just a hair
and redrill the holes in your bellhousing and you can bolt any ford tranny onto the back of any gm motor using the ford pressure plate with the gm clutch
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