I'm working on a 66 that definitely has a bad cylinder. 0 compression. I actually took the spark plug out and fitted a host to blow into the cylinder and blowby came out of the valve cover tube. So, I'm on the hunt for parts before I tear this one down. I have seen 425 motors and other parts. Can you share what the 39 degree to 45 degree motor means? Guys I ask don't know what I'm talking about, and I'm not sure how I can explain it. It seems like I need a different cam and lifters from a regular 425 offered. Can I use 455 parts in the engine? My goal is get this back to a nice stock motor on a budget.

 

Here is a technical read on the 39 versus 45 degree cam bank angle https://tech.classicoldsmobile.com/98.shtml There are a lot of things to consider when tearing into a Toro engine, as there are many specific parts, like the .921 sized lifters, that are not the easiest to obtain and can be pricey. I just finished the build on my '67 425 and I'm into it more than $7k with all the machine work and special parts (like .040 over pistons) that are just not common, and therefore higher dollar. There are also two kinds of .921 lifters, I found - one will pump oil up to the top of the motor like we need, and one will not (for an older, different displacement motor). You might send CutlassEFI a PM here on the forum, as he has been a wealth of info and a source of these parts you may need. As you tear into your motor, determine what you need to have done. It very well might be a better thing to find a much more common 455 and build that instead. The forged crank of the 425 and the power it can create is great, but it means very little in the long run if you just want to get your car on the road and enjoy it. You can use the same heads and intake from the 425 to mitigate costs, if they are in good shape. You can also swap an entire 455 rotating assembly into the 425 block if it's in good condition. You can't mix and match things, however. It's all or nothing - crank and pistons. Knowing what I know now, after a year of building and waiting, I would have been better off to grab a running 455 and drop it in my own. Live and learn.

 

The larger lifter Toro 425 has a 39 degree cam angle, the commonly found cam in most Olds engines.

 

Thanks Bob! One of the best insights on the engine so far in terms of practicality to get the car on the road. Do you know why they make this engine with a different bank angle?

 

A little advice.
Don't spend any money on parts until you have torn this engine down to determine it's condition.
You may find a condition like a cracked block or a badly scored crank that would make that engine a candidate for the scrap pile.

 

Honestly, no idea at all. I find it very interesting that they had two versions of the same motor at the same time, each being so drastically different from the other. And Charlie is so right - tear it down and inspect everything. I had jumped ahead of myself with parts purchasing well before I found my crank not only had to be turned 20 under on the main journals and 30 on the rods, but then found the thrust bearing surface had to be built up and then machined to the correct tolerances.... before I knew it I was $1000 into a crank I could have replaced for a couple hundred $$, plus the time spent hauling it from shop to shop, as no one did everything I required. THEN we can start in with how much I spent on the heads and valves and springs and on and on and on....

 

i would get a camera snake and look down into the cylinder .

 

Good advice...as is a teardown mentioned by Charlie, followed by a thorough inspection and evaluation before buying parts. Air out of the valve cover is getting past the rings or literally through the piston due to a hole.

 

Thanks guys! I will send a camera down the hole and see what evil lurks down there.

 

If you wind up needing parts or want to replace the engine I'm not too far away and have a clutter of spare parts. John

 

Does the engine spin freely with no spark plugs in it? Often times if it spins freely it’s a good indicator crank mains and rods aren’t binding up. Which should translate into a good gamble before buying.

 

The car is running, but I'm going to have to be on the lookout for a replacement.

 

Please, don't leave us hanging - what did you find, and what did you do?
Glad to hear that you've made progress.

 

This is what to look for to determine what cam bank angle you have for your engine. When you order your cam, it must be the correct angle.

 

Thanks for the visual on the bank angle. I have put the project on the back burner to focus on work but have kept feelers out there for parts.