hot 455 olds oil problems, what causes them to grenade

[455oldsuperduty]

Hey all i'm new to this platform, i'm 17 and i'm trying to make an old 455 my dad built up reliable. im trying to put this motor in a 1979 trans am. not sure on the year of the motor. my dad bought it for cheap and stuck some real change into it, cam, headers, lots of aftermarket parts made to run around 5-600 hp. Does not have anything to fix the oil issues though as when he built this motor he wasn't aware of the problems, stock oil pan, no restrictors and stock oil pump. I've heard that these olds have a tendency to grenade themselves due to oil starvation when run around 4800 rpm. the cam my dad has in it will require it to be run around this to make any power. so what do i need to do to bullet proof this engine. thanks in advance.

[joe_padavano]

Don't believe everything you hear or see on the interwebs. I've owned big block Olds motors for over half a century now, and I am not gentle with mine (including nitrous and drag strip use). I have never "grenaded" one. The real problem is uneducated builders who think every GM engine is a small block Chevy, and build that way. Obviously good internal engine build practices are required for any performance motor - deburr the block, open and smooth the oil drainback passages, etc. The restrictors that go in the oil feed holes to the cam bearings are less than worthless. A five second look at the Oldsmobile oiling diagram will show you that those passages do not feed the rockers and thus those restrictors do nothing other than increase wear on the cam bearings. A good high volume oil pump is cheap insurance. No it will NOT "suck the pan dry" as some interweb "experts" claim. Be sure the valves tips are properly set using either the GM gauge tool or equivalent. Again, many Chevy-centric machine shops are unaware of how important this is with Oldsmobile's non-adjustable valvetrain. For the street you do not need a deep oil pan or other aftermarket parts. Even an occasional track car will be fine. Cloyes double roller chain is a good investment.

[ramair]

My question would be which 455 are we talking about as other divisions other than Olds had that cubic inch and i believe that was all they had in common.  I have owned 8 Oldsmobiles from the beginning of the 455 in 1968 to the end in 1976, 

it is a engine that can be punished, I own a stock W-34 that at the factory pumped 400 horse, near 500# torque with 10.25 compression ratio, I also had a friend that had a GMC motorhome with high miles, punishment yes. Our local lake in the eighties had many jet boats powered by , you guessed it 455, still remember their roar!

[Pfeil]

4 hours ago, ramair said:

My question would be which 455 are we talking about as other divisions other than Olds had that cubic inch and i believe that was all they had in common.  I have owned 8 Oldsmobiles from the beginning of the 455 in 1968 to the end in 1976, 

it is a engine that can be punished, I own a stock W-34 that at the factory pumped 400 horse, near 500# torque with 10.25 compression ratio, I also had a friend that had a GMC motorhome with high miles, punishment yes. Our local lake in the eighties had many jet boats powered by , you guessed it 455, still remember their roar!

49 state T/A's got Pontiac's 455 (really a 456), California got an Olds 455. Production for these 455's ended in 1976 and this is a 79 T/A. The engine for a T/A in 1979 would be an optional Federal Pontiac standard deck height 400" engine. California cars would get the short deck 403 Olds engine. Either the 455 Olds or 455 Pontiac engines do not belong in a 1979 Trans Am.   

[joe_padavano]

4 hours ago, Pfeil said:

49 state T/A's got Pontiac's 455 (really a 456), California got an Olds 455. Production for these 455's ended in 1976 and this is a 79 T/A. The engine for a T/A in 1979 would be an optional Federal Pontiac standard deck height 400" engine. California cars would get the short deck 403 Olds engine. Either the 455 Olds or 455 Pontiac engines do not belong in a 1979 Trans Am.   

The Olds 455 was never installed in a Pontiac. The Olds 350 was used in Calif Firebirds in the 1977-78 model years. The Olds 403 was used in T/As for 1977-79. It is not uncommon for people to swap an Olds 455 in place of the Olds 403 in T/As. There are problems with exhaust manifolds and accessory brackets due to the taller deck height of the 455. The F-body accessory brackets for Olds motors are unique to that application and do not swap with any other Olds accessory brackets.

Edited May 14 by joe_padavano (see edit history)

[Pfeil]

11 hours ago, joe_padavano said:

The Olds 455 was never installed in a Pontiac. The Olds 350 was used in Calif Firebirds in the 1977-78 model years. The Olds 403 was used in T/As for 1977-79. It is not uncommon for people to swap an Olds 455 in place of the Olds 403 in T/As. There are problems with exhaust manifolds and accessory brackets due to the taller deck height of the 455. The F-body accessory brackets for Olds motors are unique to that application and do not swap with any other Olds accessory brackets.

You are correct, I stand corrected. The jest of the comment was however " Either the 455 Olds or 455 Pontiac engines do not belong in a 1979 Trans Am".   

[rocketraider]

Maybe not, but either beats the snot out of stuffing a big block Chevy or, worse, an LS derivative in it.😛

 

OP, a cam that requires that RPM range to make its power is going to be hard to live with on the street. Or is this TransAM going drag racing?

[Pfeil]

6 hours ago, rocketraider said:

Maybe not, but either beats the snot out of stuffing a big block Chevy or, worse, an LS derivative in it.😛

 

OP, a cam that requires that RPM range to make its power is going to be hard to live with on the street. Or is this TransAM going drag racing?

Can't disagree there either, although a Pontiac with a real Pontiac engine would be the ticket for me and if it were the other way around an Oldsmobile with an Oldsmobile engine!

[joe_padavano]

8 hours ago, Pfeil said:

Can't disagree there either, although a Pontiac with a real Pontiac engine would be the ticket for me and if it were the other way around an Oldsmobile with an Oldsmobile engine!

Concur

[Steve Moskowitz]

Of course I agree with both posts about keeping the car all Pontiac but  the OP is a 17 year old young man enthused about old cars and he owns the engine already.  In this case it is understandable and I get charged up when someone this young is entering the hobby.  His grenade comment probably came from some lunkhead who poorly maintained his car or abused it as the 455 Olds engine was almost bullet proof.  One of my jobs at Olds was to compare warranty costs on engines for the different car divisions.  The Olds was consistently either the lowest cost or slightly more than the Caddy engine of the time.  

[455oldsuperduty]

20 hours ago, rocketraider said:

Maybe not, but either beats the snot out of stuffing a big block Chevy or, worse, an LS derivative in it.😛

 

OP, a cam that requires that RPM range to make its power is going to be hard to live with on the street. Or is this TransAM going drag racing?

it will not be drag raced, my dad hoped to go to some drag races but he ran out of time for it

[455oldsuperduty]

13 hours ago, Pfeil said:

Can't disagree there either, although a Pontiac with a real Pontiac engine would be the ticket for me and if it were the other way around an Oldsmobile with an Oldsmobile engine!

We do have the original numbers matching 403 but it was blown up and pretty well ruined, needed lots of machining to make work at all and stock it only made 185 hp or something around there, we want a little more umph

[Pfeil]

I think for you, the proper answer was given to you in the very beginning by Joe Padavano. Here it is again;

 

  "Don't believe everything you hear or see on the interwebs. I've owned big block Olds motors for over half a century now, and I am not gentle with mine (including nitrous and drag strip use). I have never "grenaded" one. The real problem is uneducated builders who think every GM engine is a small block Chevy, and build that way. Obviously good internal engine build practices are required for any performance motor - deburr the block, open and smooth the oil drainback passages, etc. The restrictors that go in the oil feed holes to the cam bearings are less than worthless. A five second look at the Oldsmobile oiling diagram will show you that those passages do not feed the rockers and thus those restrictors do nothing other than increase wear on the cam bearings. A good high volume oil pump is cheap insurance. No it will NOT "suck the pan dry" as some interweb "experts" claim. Be sure the valves tips are properly set using either the GM gauge tool or equivalent. Again, many Chevy-centric machine shops are unaware of how important this is with Oldsmobile's non-adjustable valvetrain. For the street you do not need a deep oil pan or other aftermarket parts. Even an occasional track car will be fine. Cloyes double roller chain is a good investment".

[Janousek]

My dad bought a new 442 in 68' with the 400.  He went through 2 cranks that summer beating the heck out of it.  GM refused the 2nd crank, but my uncle was in Engineering at Olds.  He pulled a 3.73 ish(whatever they had( ratio rear end from the assembly line and replaced the 4.10 gear axle.   Those 400's and I believe the 455's suffer from high rpm's runs the oil up to the top end and leaves the sump low on oil and takes the rods out.  All I know is something caused his rods to start knocking and the lower gear ratio lowered the RPM's and he never had a problem.    There are some fixes that supposed to help.  I rebuilt his 455 and we did some of those tricks to get oil back down to the sump, but he doesn't run it hard.  The neat story my Dad told me since my uncle was in engineering, he could tag parts on the line and pay scrap price for them.   

 

My dad also worked assembly at Olds after the army and told me he used to cut the tabs off the wiring harness on break so they could assemble under the dash and keep up with production.  This would have been late 60's.        

[Pfeil]

5 hours ago, Janousek said:

My dad bought a new 442 in 68' with the 400.  He went through 2 cranks that summer beating the heck out of it.  GM refused the 2nd crank, but my uncle was in Engineering at Olds.  He pulled a 3.73 ish(whatever they had( ratio rear end from the assembly line and replaced the 4.10 gear axle.   Those 400's and I believe the 455's suffer from high rpm's runs the oil up to the top end and leaves the sump low on oil and takes the rods out.  All I know is something caused his rods to start knocking and the lower gear ratio lowered the RPM's and he never had a problem.    There are some fixes that supposed to help.  I rebuilt his 455 and we did some of those tricks to get oil back down to the sump, but he doesn't run it hard.  The neat story my Dad told me since my uncle was in engineering, he could tag parts on the line and pay scrap price for them.   

 

My dad also worked assembly at Olds after the army and told me he used to cut the tabs off the wiring harness on break so they could assemble under the dash and keep up with production.  This would have been late 60's.        

I'm a Pontiac guy for the most part, but here is my recollection of what happened in 68 from guys with Oldsmobile's I raced. In order to save money in engine production Oldsmobile decided to increase the size of its largest engine (425) to 455. To save money they de-bored the 400" engine from 4" to 3.87 and used the 455 crankshafts at 4.25stroke to create a new 400-inch engine. Most of the racers knew what had happened, but guys on the street tried to buzz this 400 like the older engine and guess what happened.

In the Pontiac world everyone knew you would never buzz a stock 455 Pontiac-really a 456 (unless it was a SD 455) past 5200rpm and its stroke is less than a 455 Olds (4.21 vs 4.25)-not with stock rods at least!

Edited May 20 by Pfeil (see edit history)

[joe_padavano]

Olds always reused the crankshaft from their full size car motors in the 442 motors. For the 1965-67 400, the crank was the same 3.98" stroke forged crank used in the 425. Given that stroke, the bore had to be 4.000" to get under the 400 cu in limit set by GM for the A-body cars. When the stroke was lengthened to 4.125" in 1968 to make the 455, using that same crank in the 400 for the 442s meant that the bore had to be decreased to 3.870" to hit the displacement. A lot of those long-stroke 400 motors got blown up early and replaced with 455s.

[rocketraider]

The G-block 400 with its long stroke was a great engine for a Vista Cruiser. Would have been a good truck engine too.

 

For a high revving performance engine, not so much.

 

Some years ago a 68 442 showed up at a Sunday afternoon car show. Big show card indicating "original 400". It was obviously a 403.

 

Then the guy started feeding me a line about how the factory installed the 403 as a warranty engine. Uh huh. I just let him prattle.

[Pfeil]

I don't know very much about Olds valve size, but on Pontiac 350 (really a 354) the bore is 3.88 and the 350H-O 330hp engine uses the Ram air 3 big valve head 2.11 intake and 1.77 exhaust. Engineering chamfered the H-O block at the top of the block so that the large intake valve could enter the cylinder.

My question to Joe or Glenn is, Did Olds do the same thing to the de-bored 400, and what were the valve dia. sizes.

[joe_padavano]

13 hours ago, Pfeil said:

I don't know very much about Olds valve size, but on Pontiac 350 (really a 354) the bore is 3.88 and the 350H-O 330hp engine uses the Ram air 3 big valve head 2.11 intake and 1.77 exhaust. Engineering chamfered the H-O block at the top of the block so that the large intake valve could enter the cylinder.

My question to Joe or Glenn is, Did Olds do the same thing to the de-bored 400, and what were the valve dia. sizes.

The 1968-69 G-block 400 used a 3.870" bore with 2.070/1.625 valves. The term "shrouding" comes to mind. 😉

[Pfeil]

12 hours ago, joe_padavano said:

The 1968-69 G-block 400 used a 3.870" bore with 2.070/1.625 valves. The term "shrouding" comes to mind. 😉

In Pontiac terms valve shrouding means the valve is shrouded by the combustion chamber. The chamber until 1968 was in the shape of a bathtub and the valves were at the bottom of the tub, thus the valves were shrouded since 1968 the chambers became open chambers and no shrouding of air flow in or out of the port. What I'm asking about Olds is, Did Olds Chamfer the cylinder block like Pontiac did on the 350 Pontiac with a 3.88 bore and a big valve head with 2.11 intakes to be able to enter the cylinder. See 350 Pontiac block with chamfer below,

   

[B Jake Moran]

On 5/13/2024 at 10:05 AM, 455oldsuperduty said:

Hey all i'm new to this platform, i'm 17 and i'm trying to make an old 455 my dad built up reliable. im trying to put this motor in a 1979 trans am. not sure on the year of the motor. my dad bought it for cheap and stuck some real change into it, cam, headers, lots of aftermarket parts made to run around 5-600 hp. Does not have anything to fix the oil issues though as when he built this motor he wasn't aware of the problems, stock oil pan, no restrictors and stock oil pump. I've heard that these olds have a tendency to grenade themselves due to oil starvation when run around 4800 rpm. the cam my dad has in it will require it to be run around this to make any power. so what do i need to do to bullet proof this engine. thanks in advance.

This is funny. Made me laugh.  Not deserving of a serious reply.   

[B Jake Moran]

On 5/14/2024 at 1:27 PM, rocketraider said:

Maybe not, but either beats the snot out of stuffing a big block Chevy or, worse, an LS derivative in it.😛

 

OP, a cam that requires that RPM range to make its power is going to be hard to live with on the street. Or is this TransAM going drag racing?

Exactly.  I don’t think a 17 year old knows anything like his statements.  

[kramaton]

Yes but, We were all 17

[Larry Schramm]

1 hour ago, kramaton said:

Yes but, We were all 17

 

Yes, but when I was 17 I only had the money for a worn out $50 car.  My girlfriend at the time, now wife and partner for over 50 years started with a $10.00 Corvair that I had to fix to make it driveable.  Those were much simpler days.

Edited May 23 by Larry Schramm (see edit history)

[joe_padavano]

7 hours ago, Pfeil said:

In Pontiac terms valve shrouding means the valve is shrouded by the combustion chamber. The chamber until 1968 was in the shape of a bathtub and the valves were at the bottom of the tub, thus the valves were shrouded since 1968 the chambers became open chambers and no shrouding of air flow in or out of the port. What I'm asking about Olds is, Did Olds Chamfer the cylinder block like Pontiac did on the 350 Pontiac with a 3.88 bore and a big valve head with 2.11 intakes to be able to enter the cylinder. See 350 Pontiac block with chamfer below,

   

No, Olds did not do this from the factory, but it is an old racer's trick.