Swapping in old motor
October 17th, 2018, 11:53 AM
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Swapping in old motor
Just bought a 455 race motor that was built in 2005 and has been sitting on an engine stand for 10 years. Nothing crazy just the typical 600ish hp Mondello style build with 11 1/4 mile passes. Motor turned over no problem by hand and I am hoping to install it soon. Are there any tips before I spend the time and money to get installed? Does it make sense to have a speech job look it over or run it on a stand first or is it likely the motor is good to go just by sitting for so long?
Last edited by teamwieland; October 17th, 2018 at 11:54 AM. Reason: Duplicate
October 18th, 2018, 11:51 AM
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Just drained oil. It looks excellent but thick. Guy used Valvoline Vr1 20w-50 which I will continue to use. Pretty chilly in Colorado now so not surprised how thick it is coming out. Good idea on the leak down test. I think I am most concerned about heads/valves/springs more than anything. I bought 3 sets of C heads from him as well and they have a little surface rust on them so it got me thinking what engine internals might be like. Probably should rebuild carb as well after sitting so long. If leakdown test is good I will just go for it.
October 18th, 2018, 10:43 PM
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October 19th, 2018, 09:56 PM
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Yeah gonna need highest octane gas I can get which isn’t very high in Colorado Springs. Found an engine builder near me that just builds Oldsmobile’s to run the motor on a start cart to make sure we’re good before making the swap. He said 10w-30 for sure even though previous owner ran 20w-50. The 20w-50 oil does seem pretty thick and tolerances on the build look pretty standard. Any reason to not run 10w-30? Been pretty frustrated with lack of power on the current motor so hoping to press ahead with the new motor. Appreciate all the input.
October 21st, 2018, 02:26 PM
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The guy I bought it from said it wouldn’t be a great cruiser. I’m gathering from these posts that maybe 600 hp is a big deal on a 455. My dad was a drag racer and it seemed 600 hp wasn’t that crazy out of a small block Chevy but maybe Olds motors are a different story. Will keep everyone posted.
October 21st, 2018, 06:47 PM
#15
Olds motors make great power. I’m just thinking a 455 making 600 hp probably had a pretty radical cam and very high compression.
id either have them run it on the stand to see what it does or take a peak inside to see what kinda compression the motors at.
most people don’t want to run super high compression motors on the street. then you also have a fuel issue. If that thing makes 600 hp your gonna have to run high octane fuel for sure.
sounds like a nice motor though. Post a few pics of you can. Maybe the guys can tell from the photos what kind of power you may be able to make.
does it have iron heads? Or aluminum?
id either have them run it on the stand to see what it does or take a peak inside to see what kinda compression the motors at.
most people don’t want to run super high compression motors on the street. then you also have a fuel issue. If that thing makes 600 hp your gonna have to run high octane fuel for sure.
sounds like a nice motor though. Post a few pics of you can. Maybe the guys can tell from the photos what kind of power you may be able to make.
does it have iron heads? Or aluminum?
Last edited by GreekDog; October 21st, 2018 at 06:53 PM.
October 22nd, 2018, 02:17 PM
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Found an Olds engine builder nearby who can run the motor to see where we are at. I gave him build specs and he confirmed it as a ~600 hp build and not very streetable. Now I need to decide on upgrading to at least 3000 rpm converter and some other things, or figuring out how to get the stock motor pulling its weight more. I say go big or go home. I can provide specs if anyone cares.
October 28th, 2018, 03:04 PM
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Moving forward with the motor swap and will take advice of others that this motor is too much to be streetable. Looking for some advice on compression ratio. Gentlemen I bought motor from recalls is being 11.5 to 1 compression, but not sure. Engine builder tested all 8 cylinders at 210 psi, which he said suggests at least 11.5 to 1 but could be even higher. I'm trying to confirm the compression ratio so I can have Comp Cams recommend a new cam package to make the motor more drivable. Does anyone have any experience estimating compression ratio based on that information or are there just too many other variable to know? Happy to provide other specs if that will help.
October 28th, 2018, 08:57 PM
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The oinly way to know is to pull at least one head (or both, preferably) to CC the chamber, check the stroke length, measure the thickness of the head gasket used, CC the top of the piston, and measure how much below the deck it resides..... I would also blueprint the cam timing events and lift so you know what you have, or pull it out and check the grind/part numbers on the rear cam journal face. Also, do you know if this is a Hydraulic or solid roller or Hydraulic/Solid Flat tappet cam? This is the time to find out. I also highly recommend checking the bearings out on the rods and mains, and checking the bores for any damage or weird marks. You can inspect the piston skirts on the bottom when you have the engine on a stand. A little due diligence now will save you a lot of heartache and money later. Also a good time to test the valvesprings for open and closed pressures and check the valve job.
Depending on if you have E85 fuel nearby, or you want to use it, as well as how big of a cam it has in it now, you might be able to run it just fine how it is. The larger the cam, typically the more octane tolerant it is if you keep timing down to a realistic number, especially at higher elevation like you are at (Colorado Springs areas).
Depending on the cam duration size @.050, it will dictate what RPM range the engine makes power.
With E85, you can have high compression and put a smaller cam in, and match the converter to the cam to make it more streetable. If the cam is much more than 245-250 degrees @ .050, it won't be as much fun unless you get a converter in the 3500-4000 range and you have 4.10 gears or higher numerically.
A high compression, medium-agressive cammed 455 on E85 will be torque monster.
Depending on if you have E85 fuel nearby, or you want to use it, as well as how big of a cam it has in it now, you might be able to run it just fine how it is. The larger the cam, typically the more octane tolerant it is if you keep timing down to a realistic number, especially at higher elevation like you are at (Colorado Springs areas).
Depending on the cam duration size @.050, it will dictate what RPM range the engine makes power.
With E85, you can have high compression and put a smaller cam in, and match the converter to the cam to make it more streetable. If the cam is much more than 245-250 degrees @ .050, it won't be as much fun unless you get a converter in the 3500-4000 range and you have 4.10 gears or higher numerically.
A high compression, medium-agressive cammed 455 on E85 will be torque monster.
October 29th, 2018, 06:38 AM
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Thanks Battenrunner. Not sure I want to even consider the e85 route, I get crappy enough fuel economy already thank you. Motor has a huge solid lifter flat tappet cam now but I will be changing that to something more drivable. Since it already has Harland Sharp roller rockers I will probably just go hydraulic roller cam too. No way I want to drive around with a 4000 rpm converter so I’m hoping to find a good setup for the 2500 rpm range. The 3.23s gotta go too. I have another rear with 4.10s and the axle guy here in the Springs thinks he has gears for 3.90s which would be nice. I just don’t know a lot about cams and I will probably rely on Comp Cams to suggest the right cam for me. At the end of the day I want the car to be a lot of fun to drive and if that means a much smaller cam then so be it. Appreciate the input.
October 29th, 2018, 07:55 AM
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The main reason I suggested E85 was that you want the engine to make a lot of power on the street, and I doubt you want to change pistons.
11.5:1 won’t work with even the best pump gas and a huge cam if you have iron heads. Apparently, about 10.5:1 is the highest you can go here at elevations of 5,000+ feet. Again, this all comes down to pulling the heads and calculating the true static compression ratio. You can fiddle with cam timing some to change the effective compression ratio and cylinder pressures.
Comp grinds a good cam, but it is a steel billet roller, which will require a bronze gear on the distributor, and they wear, which sucks for a street car.
Lunati has SADI Hyd. Roller cam cores and they make great street roller cams because you can run a nitrided/melonized distributor gears with them that come on factory MSD distributors and/or can be purchased separately for a .491 or .500 shaft.
Depending on what your valve Springs spec out at if you can reuse them, most moderate hydraulic rollers will want 150lbs on the seat, and 350-380lbs open pressure.
11.5:1 won’t work with even the best pump gas and a huge cam if you have iron heads. Apparently, about 10.5:1 is the highest you can go here at elevations of 5,000+ feet. Again, this all comes down to pulling the heads and calculating the true static compression ratio. You can fiddle with cam timing some to change the effective compression ratio and cylinder pressures.
Comp grinds a good cam, but it is a steel billet roller, which will require a bronze gear on the distributor, and they wear, which sucks for a street car.
Lunati has SADI Hyd. Roller cam cores and they make great street roller cams because you can run a nitrided/melonized distributor gears with them that come on factory MSD distributors and/or can be purchased separately for a .491 or .500 shaft.
Depending on what your valve Springs spec out at if you can reuse them, most moderate hydraulic rollers will want 150lbs on the seat, and 350-380lbs open pressure.
October 29th, 2018, 08:04 AM
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Thanks for the input man. Comp cams said take off 1 compression point for our elevation, so 11.5 is considered 10.5 here. Not sure what the compression limitation of cast iron heads is caused by. Motor has Ga heads that have been completely reworked and built with high end parts. Guessing heads are coming off to look into a slight knocking noise so we can get exact measurements then.
October 29th, 2018, 09:19 AM
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10.5:1 static compression at this elevation is like 9.5:1 at sea level, which is about max for pump gas.
But 11.5:1 here is like 10.5:1 at sea level, which won’t work with pump gas unless you pull a bunch of timing out and make it sluggish.... defeating the purpose of installing a salty engine.
Iron heads hold more heat in the chamber, and are more prone to detonation. Aluminum heads will allow about a full point higher compression than iron without detonation.
Sounds like the engine needs inspection no matter what if it is making any noise.
As for your heads, it comes down to the quality of port work and flow capabilities. A good porter can make a lot of power with iron heads if they know how.
But 11.5:1 here is like 10.5:1 at sea level, which won’t work with pump gas unless you pull a bunch of timing out and make it sluggish.... defeating the purpose of installing a salty engine.
Iron heads hold more heat in the chamber, and are more prone to detonation. Aluminum heads will allow about a full point higher compression than iron without detonation.
Sounds like the engine needs inspection no matter what if it is making any noise.
As for your heads, it comes down to the quality of port work and flow capabilities. A good porter can make a lot of power with iron heads if they know how.
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