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Hello guys, my name is Johny and I am writing from Poland.I have to rebuild my engine.
Last winter I bought Cadillac Seville 1978, the car is some kind of barn find ( 10 years in garage )
It has Oldsmobile 350 enigine. 5,7 V8 ( 350cui ) fuel EFI.
Fuel system was incomplete, so I decided to put a carb.
I have Rochester Quadrajet 4 barrel Carb, intake manifold Edelbrock Olds 350 Performer nr 3711.
Ignition original HEI system.
I have to rebuild my engine because it was running without oil pressure.
Engine block is 557752 - 3B, small block, oldsmobile 350.
Crankshaft number 556607.
Cylinder heads 3A witch 75cc chamber, intake valve 1.880, exhaust valves 1.507
This engine in Cadillac generate only 180hp, CR 8.0 : 1.
I have read Bill Trovato Book about Oldsmobile v8 engines.
I have many questions, I want to put my Caddi to live, it should be a budget rebuild.
1. I have to buy Crankshaft with connecting rods.
My crankshaft is a junk, i will try to show some photos.
Maybe someone of you, have a crankshaft with connecting rods to sell ( in good shape to grinding )
2. Pistons looks original - diameter is about 4.048 in . Are they std? or oversized?
My cylinder bores diameter is about from 4,057-4,060.
Greetings from Poland !
Johny
Crank
Last edited by Johny; June 24th, 2021 at 06:12 AM.
It sounds like your pistons and cylinders are standard bore. I assume you are looking for a mild power upgrade? What octane gas do you want to run? Your windowed main block is Ok at mild power levels as is. You can probably get any basic crankshaft kit, just get it balanced for YOUR motor. Your cylinder heads are crack prone, in the exhaust ports, I believe. They also have larger chambers and a terrible flowing exhaust port. It depends where and how deep the cracks are, if they will be an issue. I went through this with Dodge Magnum heads, not fun. Basically if you want to raise your compression any amount, Speedpro flat top pistons will be needed and your block overbored .030". They need a minimum of .004" clearance, the instructions say .002" and the box says .001", both are not enough and end badly. If you only do clean up milling and decking, they will give low 9 to 1 compression. 0 deck, 9.6+ to 1, how much depends on actual head CC. It looks like DSS discontinued their 3cc dish pistons, now only have a 12cc dish. That or the 10cc Mahle pistons, both would give 8 to about 8.6 to 1 depending if you 0 deck and head CC. Don't even consider stock replacement pistons, they have a 10cc larger dish than your stock pistons and are shorter. Any more than 7 to 1 compression without a lot milling is not possible. Camshaft selection will depend on where you end up with compression. Good luck.
Those are the pistons are the ones I was talking about, you need to tell the machine shop to ignore the box and instructions for piston to cylinder wall clearance. The generic 204/214 cam is as small as I would go, especially running regular fuel. Your idle circuits on that Qjet will probably need modifications as well, depending on the model year which is stamped on the driver's side of the carb.
Your 95 is our 89. Don’t go too high on the compression.
I am thinking about 9.5 -10 :1. I can also drive our 98, there is only few cents in price.
Today I want to pull off Pistons pin. Something is strange. I have rebuild a few European engines yet and the pin has protection. In my engine there is no protection, and pin sits very tight. To pull off I used hydraulic press ( about 4 tons of pressure) Is this normal? ( sorry for my technical English! , I hope you Understand me )
All Olds used press fit wrist pins. You’re probably used to floating pins with locks. Ain’t that way on Olds unless you go with that type of aftermarket pieces.
The method to remove "press fit pins" is heating with a torch but not too hot as that can potentially make the rods brittle. Bill Travato mentioned the temp as 400 degrees Farenheit. He smeared engine oil on the pin and when it burnt, it was hot enough to press them out. It makes sense with a motor oils flash point.
What you are encountering with the piston wrist pins is correct. The tight fit into the small end of the connecting rod is an "interference fit", that is what keeps the wrist pin in place, there are no clips.
The method to remove "press fit pins" is heating with a torch but not too hot as that can potentially make the rods brittle. Bill Travato mentioned the temp as 400 degrees Farenheit. He smeared engine oil on the pin and when it burnt, it was hot enough to press them out. It makes sense with a motor oils flash point.
Travato says if heated to hot they will potentially get brittle ?
I used "press fit pins" in old 2 stroke engines ( motorbikes ) . I warm piston on electric oven plate , then I put a pin ( after few days in freezer ) only by hand with gloves.
I put an advertise, I am waiting for some info about crankshaft with connecting rods. I am thinking now about a new cam. Standart cam specification:
.400"/.400" lift
186°/202° duration @ .050"
250°/264° advertised duration
What do you think about Lunati 10420700? I don't want problems with vacum and have quite standart RMP Range, I want to leave standart flat tappet.Series: Voodoo Make: Oldsmobile Engine: 260-455 V8
RPM Range: 800 to 5000
Camshaft Type: Hydraulic Flat Tappet
Intake Valve Lift:.466"
Exhaust Valve Lift:.485"
Advertised Intake Duration:250°
Advertised Exhaust Duration:256°
Intake Duration @ .050":207°
Exhaust Duration @ .050":213°
Lobe Separation:112°
In the dealership we used a GM tool probably sold by Kent-Moore to support the rod while pressing. It went inside the bottom of the piston and supported the rod while pressing. The piston continued to move freely and no heat was used. I'm not saying using heat is wrong, rather explaining another method.
In the dealership we used a GM tool probably sold by Kent-Moore to support the rod while pressing. It went inside the bottom of the piston and supported the rod while pressing. The piston continued to move freely and no heat was used. I'm not saying using heat is wrong, rather explaining another method.
That makes sense, probably the best way if he wanted to keep the pistons.
I used "press fit pins" in old 2 stroke engines ( motorbikes ) . I warm piston on electric oven plate , then I put a pin ( after few days in freezer ) only by hand with gloves.
I put an advertise, I am waiting for some info about crankshaft with connecting rods. I am thinking now about a new cam. Standart cam specification:
.400"/.400" lift
186°/202° duration @ .050"
250°/264° advertised duration
What do you think about Lunati 10420700? I don't want problems with vacum and have quite standart RMP Range, I want to leave standart flat tappet.Series: Voodoo Make: Oldsmobile Engine: 260-455 V8
RPM Range: 800 to 5000
Camshaft Type: Hydraulic Flat Tappet
Intake Valve Lift:.466"
Exhaust Valve Lift:.485"
Advertised Intake Duration:250°
Advertised Exhaust Duration:256°
Intake Duration @ .050":207°
Exhaust Duration @ .050":213°
Lobe Separation:112°
That should be pretty mild, similar to the 204/214 cam I mentioned. Are you getting the factory rods resized? How bad were the rod bearings spun?
"Rod bearings spin? , I don't understand"
How many of the bearings rotated (spin) inside the connecting rods? This can be seen by damage to the small tab(s) on the back of the bearing shell being damaged.
Same for the main bearings. Did any of them rotate their position (spin) and damage that tab on the shell.
When the bearing spins inside the rod or main cap it causes damage to the rod and or the main cap and block, requiring additional machining to correct the damage.
"Rod bearings spin? , I don't understand"
How many of the bearings rotated (spin) inside the connecting rods? This can be seen by damage to the small tab(s) on the back of the bearing shell being damaged.
Same for the main bearings. Did any of them rotate their position (spin) and damage that tab on the shell.
When the bearing spins inside the rod or main cap it causes damage to the rod and or the main cap and block, requiring additional machining to correct the damage.
Good luck!!!
Main bearings didn't rotate. They were in quite good shape. A little bit luck...
Wow, thats hard to believe after seeing that crank lol.
A little bit of luck.
What do you think guys about this cam? It is produce by Melling, its really cheap.
Advertised Exhaust Duration 289
Advertised Intake Duration 280
Cam Type Hydraulic
Computer Controlled Compatible Yes
Exhaust Duration at .050 inch Lift 214
Exhaust Valve Lift (in) .473
Intake Duration at .050 Inch Lift 204
Intake Valve Lift (in) .449
What do you think guys about this cam? It is produce by Melling, its really cheap.
Advertised Exhaust Duration 289
Advertised Intake Duration 280
Cam Type Hydraulic
Computer Controlled Compatible Yes
Exhaust Duration at .050 inch Lift 214
Exhaust Valve Lift (in) .473
Intake Duration at .050 Inch Lift 204
Intake Valve Lift (in) .449
It should be cheap, they make a million of those a year. A 50 year old design, there are better ones out there.
That cam has a lot of advertised duration for 204 @ .050” duration. You should be able to find a similar profile that’s around 260 advertised, which should help build more cylinder pressure.
That cam has a lot of advertised duration for 204 @ .050” duration. You should be able to find a similar profile that’s around 260 advertised, which should help build more cylinder pressure.
Thanks for tip. What do you think about that cam? Grind Number: XE256H Engine Family: Oldsmobile 260-455 c.i. 8 Cylinder (1967-1990) RPM Operating Range: 1,000-5,200 Advertised Intake Duration: 256 Advertised Exhaust Duration: 268 Intake Duration at .050 Inch Lift: 212 Exhaust Duration at .050 Inch Lift: 218 Intake Valve Lift: 0.453 Exhaust Valve Lift: 0.456
I used that exact cam and it worked Ok. It is better than stock at least. What is the plan with the rest of the motor?
Melling cam cost about 90$. Melling recommends also stronger valve springs MELLING VS720 ( only 10$ for set ).
I’m not a fan of that XE256H, but it would probably work fine. The lift seems low for a cam with 212 @.050” duration. Other cams with similar duration have a lot more lift than that one, and with similar lift, have a shorter duration.
For .450” lift, I look for around 204 @ .050” and 260 advertised duration.
For 210-ish @ .050” lift, around 270 advertised duration.
But I’m not an engine builder, just a hobbyist gearhead.
No. I will buy +0,40 new piston set , and machining cylinders bores.
It needs a .040" overbore? The 24cc dish cast replacement pistons will give you 7.8 to 1 at best. The block may need a .040" or removed from the deck to reach 0. That is with a 73cc Combustion chamber and .042" Felpro Blue head gaskets. The new Mahle forged 4032 10cc dish pistons are available in a 4.100" bore, require only .013" to 0 deck and are much lighter and coated. They also have a 1mm/1mm/2mm ring pack. The same 0 deck yields 8.9 to 1 with the same 73cc Combustion chamber.
Yeah, be aware that aftermarket cast pistons will be way short on compression height, which will drastically affect compression ratio as said above. Forged pistons don’t have this “shortcoming”.
It needs a .040" overbore? The 24cc dish cast replacement pistons will give you 7.8 to 1 at best. The block may need a .040" or removed from the deck to reach 0. That is with a 73cc Combustion chamber and .042" Felpro Blue head gaskets. The new Mahle forged 4032 10cc dish pistons are available in a 4.100" bore, require only .013" to 0 deck and are much lighter and coated. They also have a 1mm/1mm/2mm ring pack. The same 0 deck yields 8.9 to 1 with the same 73cc Combustion chamber.
I’m not a fan of that XE256H, but it would probably work fine. The lift seems low for a cam with 212 @.050” duration. Other cams with similar duration have a lot more lift than that one, and with similar lift, have a shorter duration.
For .450” lift, I look for around 204 @ .050” and 260 advertised duration.
For 210-ish @ .050” lift, around 270 advertised duration.
But I’m not an engine builder, just a hobbyist gearhead.
Depending on what his 3A heads actually measure, 75cc is the spec, if they they measure that minus a couple of CC for a clean up mill. Even just enough of a decking to flatten it, those sit .025" in the hole before decking, he will probably still be around 9.25 to 1.
I've ordered flat tops SpeedPro Pistons +0,30 oversize. The manufacturer informs about compresion ratio :
w/62.5cc heads 10.49:1 / w/70.0cc heads 9.64:1 / w/75.0cc heads 9.16:1
My 3A heads are standard. high size. I want to put bigger valves especially exhaust valves, and do some porting cylinder heads and test them on flow bench.
In Europe we usually use 95 petrol ( your 89 like cutlassefi said ).
What do you think about milling cylinder heads to get 70cc? CR 9.64:1 won't be to much for 89 petrol?
In a few days a I have to order a cam, I need good idle, stanard RMP , good low and middle.
I will also make a new 2.5 double exhaust, with x-pipe a double flowmaster 44.
Here is a link to a good calculator. https://uempistons.com/p-27-compress...alculator.html Their basic part is fine, the dynamic calculator is questionable. It makes a huge difference if you 0 deck the motor. That Melling cam is too small if you 0 deck and probably even if you don't. Make sure the 3A heads aren't cracked, a former member confirmed that is true. Also the exhaust ports are terrible on all "A" heads. Both bowls should be opened with a cutter for a larger 2" or 2.07" and 1.625" exhaust valve. Also those pistons need an extra .004" of additional piston to wall clearance or scuffing and overheating will occur.
Here is a link to a good calculator. https://uempistons.com/p-27-compress...alculator.html Their basic part is fine, the dynamic calculator is questionable. It makes a huge difference if you 0 deck the motor. That Melling cam is too small if you 0 deck and probably even if you don't. Make sure the 3A heads aren't cracked, a former member confirmed that is true. Also the exhaust ports are terrible on all "A" heads. Both bowls should be opened with a cutter for a larger 2" or 2.07" and 1.625" exhaust valve. Also those pistons need an extra .004" of additional piston to wall clearance or scuffing and overheating will occur.
Thanks for calculator.
With standard cylinder head gaskiet produced by Victor Reinz and standard cylinder head chamber 75cc I have CR 9,17
After milling cylinder head down to 70cc, I will get CR 9,66
The Victor head gaskets may be slightly different. You will need to get a caliper and measure the initial thickness and the gasket bore. The 77 to 80 head gaskets are different. The 76 and older Felpro head gaskets are .042" compressed. I believe the gasket bore is 4.230". The Victor are made by Felpro, probably the same specs, you won't know till you measure them. The thickness effects compression more than gasket bore. Measure the head CC. It is the final head CC after the new valves are installed that count. You can polish the chambers to drop compression slightly. I am doing that on my build. Early heads are more than the stated 64cc number, usually 68 to 70. The 4A set I measured were two CC over the 84cc spec, 86cc. The two sets of #8 heads were 77 to 78cc, just under the 79cc spec. Both had shim head gaskets, so untouched motors. Figure your final bore for 4.091".
Hello Guys!
I've bought some parts, they arrived few days ago:
- New Pistons flat tops +0,30 Sealed Power with Hastings rings
- Milodon valves: in take 2,07 exhaust 1,624
- used crankshaft from cutllas
- used crankshaft from seville - light castings
I have a question, because I am Looking for 8 Connecting rods. They should me remanufactured in US. Maybe somebody know any company like Engintech where I can buy such rods? Are my rods typical like for Oldsmobile? I want to buy from Engintech but i don't get dimensions from their catalogue.
If the Cutlass crankshaft has a big "N" on it, use it. Even the lightweight crankshaft will be fine for your build. All the 260 through 403 use the same specs for connecting rods. The 403 are a psychically bigger rod but the dimensions you show are the same. Can your rods not be resized? I have seen reman stock rods on Ebay and places like Summit. Otherwise aftermarket performance rods start at about $500 US a set. It is awesome that direct fit performance rods now exist. Good luck.
June 24th, 2021, 04:37 AM
Olds 350 engine - rebuild
