Help! Standard pistons size , 1949 Buick super

[Selim 0]

Rebuilding motor for my Buick 1949

need to know standard size of pistons to buy new ones

also any clue where I could buy them from?

pics of engine attached

[Selim 0]

ebuilding motor for my Buick 1949

need to know standard size of pistons to buy new ones

also any clue where I could buy them from?

pics of engine attached

[Selim 0]

ebuilding motor for my Buick 1949

need to know standard size of pistons to buy new ones

also any clue where I could buy them from?

pics of engine attached

 

[Leif Holmberg 309]

There are 2 size of engines 248cu in,and 320 cu in.Try this if your engine is a 248 cu in..https://www.kanter.com/content/Buick/kanter_Buick_1949_Engine_Parts_5793.html

Leif in Sweden.

Edited January 9 by Leif Holmberg (see edit history)

[Dave Henderson 137]

Standard bore for the '49 Super is 3 3/32 as per Motor's Auto Repair Manual..  Egge Machine Company is the leading supplier for antique vehicle pistons.

[Leif Holmberg 309]

Why are you changing the pistons,broken or what???????? They looks really good in the picture.

Leif in Sweden.

[Selim 0]

:indeed the seem to b ok (pistons) with slight friction the car over heated and affected one of the pistons  So I was looking to buy Pistons a bit more than standard (7,85cm) then we take standard rings If u don’t have a bigger size piston then I d go for standard pistons but then I ll have the rings .020 Connecting Rod Bearings - .020 Main Bearings - , .020, Also full set of gaskets    These items in order to overhaul the engine is that correct? Excuse my I ignorance but it’s my first time

[Dave Henderson 137]

With the crankshaft journals being .020, it would seem likely the cylinders were perhaps bored oversize at the same time, so look for an indication that that may have been done.   Scrape the carbon off the top of the pistons and look for an oversize marking. Would be best to have someone mike the bores.  If they are in fact standard you should measure the cylinder's taper to see if it will take just a ring job. .  Ring size needs to match the piston size .

Edited January 9 by Dave Henderson (see edit history)

[Ben Bruce aka First Born 2,300]

Selim, could you please post another picture of the driver side of the engine, below the manifold?

 

  Thanks

  Ben

[PFitz 176]

The answer to your piston size is in the bores. 

 

Even if the bores are good, as Dave mentioned above, they may  not be standard. The pistons need to be sized to whatever the "actual" bore size is, plus whatever the clearance is. If you order pistons that's one of the main questions a good piston manufacture will ask you. You also need to know that bore size to order ring sets.

 

If the bores are worn oval and tapered, new pistons likely won't help you, just waste your money. If you have wear that is machined and honed out that's the bore size you give to the piston maker and how much piston-to-bore clearance your engine needs. 

 

Find the bore, then find the pistons that work properly with it.

 

Paul

[Selim 0]

30 minutes ago, Ben Bruce aka First Born said:

Selim, could you please post another picture of the driver side of the engine, below the manifold?

 

  Thanks

  Ben

 

[Selim 0]

[Selim 0]

27 minutes ago, PFitz said:

The answer to your piston size is in the bores. 

 

Even if the bores are good, as Dave mentioned above, they may  not be standard. The pistons need to be sized to whatever the "actual" bore size is, plus whatever the clearance is. If you order pistons that's one of the main questions a good piston manufacture will ask you. You also need to know that bore size to order ring sets.

 

If the bores are worn oval and tapered, new pistons likely won't help you, just waste your money. If you have wear that is machined and honed out that's the bore size you give to the piston maker and how much piston-to-bore clearance your engine needs. 

 

Find the bore, then find the pistons that work properly with it.

 

Paul

Everything is standard , pistons, bore .. yet there is some wear in one of pistons but not a big deal. Problem is there is no spare parts at all where I m staying so they will manufacture the rings, bearings and will scrap a layer from bore in order to clear it, that would lead to a gap between pistons and bore, so they will fill that gap with manufactured steel layer like a wall between the 2 in order to not leave any gaps , and using the same original pistons of the engine 

now I don’t know whether I should follow that plan or resort to first solution of buying Complete overhaul kit with bigger size pistons as explained earlier ? 

[Ben Bruce aka First Born 2,300]

Thanks for the pictures. They confirm a 248 CI engine. And POWER STEERING.

 Where are you?

 

  Ben

[Tinindian 714]

Since your original problem was overheating NOW is the time to knock out all the core plugs and clean out the water passages.

I personally would use all new pistons, pins and rings after the block was bored/honed to a specific oversize.  Make sure to have the rods aligned, new bearings would not hurt either.

[kgreen 1,109]

Since you mention that you are new to this, here is a website for beginners that gives you a good general idea for engine rebuilding.  Yes, the engine features is different so just focus on the concepts.  The straight 8 has peculiarities and that is where this board will be most helpful.  One of the processes you describe is called re-sleeving which is what you do if the cylinder(s) are in very bad shape or are at the end of their overboard possibility.  Here in Atlanta that costs about $150 per cylinder (where are you?)  A new piston would be less than that.  The decision can't be made until you measure to determine the bore is worn with a taper or out of round.

 

Remember: bag-n-tag, measure everything then decide your coarse of action.

[edinmass 1,127]

On 1/9/2019 at 5:59 AM, Dave Henderson said:

Standard bore for the '49 Super is 3 3/32 as per Motor's Auto Repair Manual..  Egge Machine Company is the leading supplier for antique vehicle pistons.

 

 

I do NOT agree...........and most people here would also......also, it has been reported they no longer make pistons, they resell from other suppliers........not sure about how correct that is. I like many others have had very poor service and poor quality parts from the above company, I would use anyone else.........

[PFitz 176]

29 minutes ago, edinmass said:

 

 

I do NOT agree...........and most people here would also......also, it has been reported they no longer make pistons, they resell from other suppliers........not sure about how correct that is. I like many others have had very poor service and poor quality parts from the above company, I would use anyone else.........

 

Add me to that list, also.

 

Switched to  only using Ross forged pistons years ago.  Stronger, lighter, quieter, and far better quality control.

 

Paul

Edited January 10 by PFitz (see edit history)

[Restorer32 1,014]

Regardless who you use for cast pistons the ultimate source is likely the same. We needed pistons for a '27 Kissel. Egge could not supply them, saying they had had a fire and their pattern for our particular size piston was destroyed. We then called one of the other suppliers of pistons and got the same story. They had had a fire. Called yet a third supplier and you guessed it, they had a fire. We finally had to buy a very expensive set of forged pistons, way overkill for the low compression Kissel engine.