palmers65

Was wondering if I can take my olds 350 motor and install a 400 crank to turn it into a stroker motor? I know you can do this to chevy motors (sorry I know this is a bad word) but can you do it with olds motors as in a previous letter by eighttime am looking to add power to my motor, was originally thinking stroker until I was told can't do it with an olds because they didn't make a 400 and low and behold they do! Still tossing around the idea of a big block too.
Question 2 went to add oil while it was running and the oil burped back up through the tube, I know it has a bigger oil pump in it could this cause it? Or could it have been that the pcv valve was in the valve cover but was not getting vacuum or some other problem?
Question 3 It has a 3 speed auto in it that doesn't kick down when you stomp on the throttle, shouldn't it kick down? And what could be some causes?

Rallye469

Can't help with all the questions but...

The 400 is a BB and your 350 is a SB.
This will mean you'll have to turn down the main journals
of the 400 crank .5" in order for it to even fit in the 350.
As far as it actually rotating?
No idea if you'd have to notch the block.
You'd probably have to get custom rods & pistons as well.
(this isn't a swap I've ever heard of, although I bet some one here
has tried it!)

However, people do put 425 cranks in the DX(diesel) 350's.

joe_padavano

You can do this with a Chevy because both the 350 and 400 are small blocks. The fact that the 400 crank will drop into a 350 block allows the Chevy types to build a low cost 383. There's nothing magic about this displacement, it just happens to be what you get when you combine these existing factory parts.

Now, as others have mentioned, the Olds 400 is a big block, the Olds 350 is a small block. These are completely different than the Chevy motors, so Chevy ways of building things don't apply. Now, the major external difference between the BBO and the SBO is the taller deck height on the BBO to allow for the longer stroke. There is also a key internal difference, in that the BBO uses larger bearings than the SBO. The bore spacing is the same, so theoretically you could have a BBO crank turned down to fit an SBO block. The easy alternative is to use an Olds diesel block, which already had BBO-sized bearings. Of course, then you get into things like custom rods and pistons, which rapidly escalates the price.

The better question is, why bother? The 403 Olds is a small block and is a direct bolt-in for the 350. Note that all SBO cranks use the same stroke, so it's worthless to swap a 403 crank into a 350, you still get a 350 (however, swapping a 330 crank into a later 350 or 403 gives you a forged crank). And while the 403 is a direct bolt-in, it takes very little additional work to also swap in a 455 in place of that 350. Either the 403 or the 455 (or 425 or 400) swap will be less expensive than the custom parts needed to build a 350 Olds stroker.

palmers65

Wow thanks for the help I forgot about the 400 being a big block!

Oldsguy

About the oil burping back on you, mentioned a "bigger" pump. What do you mean? I don't think that should happen. How do you know the car was low on oil? You check oil level when the engine is not running anyway. Not following the sequence of events and what really happened to cause the burping.
About the kickdown, has the kickdown linkage been messed with? Is it even functional?

joe_padavano

The oil fill tube dumps into the crankcase. It has nothing to do with the oil pump. There are a couple of thoughts, however. First, if your PCV system is not functioning properly, you will build up pressure in the crankcase. Second, there is a small sheet metal deflector that snaps into place in the block below the oil fill tube. If this has been inadvertently left out, you may get splash back up the tube when the engine is running. And finally, as Dan correctly points out, why are you filling the oil with the engine running anyway?

Since a 3 speed AT was not available in the 65 cars, it's been added by someone. My guess is that whoever installed it did not connect the kickdown properly. The first problem is to determine which trans you have - TH400 or TH350. A TH400 uses an electric kickdown, same as the Jetaway that was used in the 65s. There should be a round electric switch on the throttle linkage on the engine side of the firewall. This switch can be used to operate the kickdown on a TH400. If the trans is a TH350, it uses a cable kickdown and you will need to route the cable from the trans to the throttle lever on the carb.

palmers65

Thanks for the help! Joe you answered my next question about the electrical connection that was on the throttle linkage noticed it the other night and was going to ask about it so now I know!
Don't ask about the engine running while filling someone else was helping me and he did it while I wasn't around. I believe he checked it and it was half a quart low so he started it to warm it up then went and got the oil and added it. so now I have to track down the electrical and also make sure it is the right part. was told it was a TH350 but this same guy told me the motor was a w motor too.(Also this same person left 4 empty beer cans under the driver seat) previous owner by the way. Once again thanks for all the help! Joe you also helped me with the W motor question on another website about a month ago! More questions to follow I am sure!

88 coupe

Interesting how the term “Stroker” has evolved from a Guys name, into an Internet buzzword.

Not a “drop in”. .200” must be removed from the Mains.

The “magic” is in the perception. “383 stroker” Doesn't it just sound impressive?

So impressive, that its shortcomings go unnoticed.

The same laws of physics apply to both.

Just as the 400 uses larger bearings than the 350.

It's been done, more than once. Solves the “bearing speed” problem, but creates another, with the “poor” rod/stroke ratio. Same problem that was designed into the 400 (so, to the 383) Chev.

Same main journals, same bearing speed. Same “rod angle problem.

As I said before,

https://classicoldsmobile.com/forums...html#post16730

it can easily be done with off the self parts.

To be different? I don't see a “383” as being different, but the number certainly draws a lot more attention than my 437.

The term “forged crank” can also impress an audience.

Cheap and easy, with good results.

Norm

Rallye469

That's why I did it!
No other reason than I like to say the word 'forged'.

palmers65

Now the question is how do I Identify the Transmission? Where do I find the numbers at? Thanks!

joe_padavano

Never mind the numbers. Look at the trans oil pan. If it's square with one corner cut off, it's a TH350. If it's irregular and looks vaguely like the state of Texas, it's a TH400. Or, use this guide:

http://www.autotran.us/gmABpg26.htm

joe_padavano

You've now exceeded the limits of my SBC knowledge. Thanks for the clarification.


But not the same "laws" of parts interchangeability.

palmers65

Cool Thanks again! Like I said the guy who had it did a chop job on it. When I use the turn signal to turn right I get hazards! So will have to look at that because the electrial part may have been left on when he did the motor swap. He welded in parts from van conversion cutouts for the floorboards and trunk so you can understand the nightmare we are going through trying to get it all looking halfways right. Will I be able to buy the cable at a parts store or shop for it? And any idea what length speedometer cable I might need? I looked it up and saw there was three different lengths listed.

Eighttime

I just thought I'd chime in here and narrow what we are currently doing. We have three different issues we are dealing with concerning the trans kickdown.

1. The car is a '65.
2. The car has a '69-'70 Olds 350/350 Turbo Trans.
3. The car also has a Holley(probably 600) 4 barrell instead of Q-Jet(although it's in a box in the garage).

If a trans kickdown cable is required, and we can find one, what all is required to get this thing to shift correctly again? We want to stick with the original pedal and pedal linkage(the "roller pedal"is kinda cool) but the electric solenoid to kickdown the '65 trans can go away. This throttle linkage has more connections than AT&T! And BTW, changing the engine or trans isn't an option right now. She runs good, if you manually shift through the gears...Thanks.

joe_padavano

There are only two connections to the trans that you need to worry about for proper shifting - the vacuum line to the modulator and the kickdown cable. The vac line simply needs to be connected to a manifold vacuum source. The cable needs to be connected to the throttle lever on the carb such that the cable us fully pulled out at wide open throttle. You will need to find or fabricate a bracket to hold the cable sheath. Usually these cables snap into a square hole in either the bracket or (for the 69-72 cars) the firewall. A good source for the bracket and cable is a 1970s vintage Olds with TH350. If that doesn't allow the trans to shift properly, there's another problem with the trans.

Eighttime

Ok now we're getting somewhere. The vacuum IS attached to manifold source and we've already purchased a new modulator. Palmer is telling me that he doesn't recall seeing any kind of linkage on the side of the trans.,but I haven't personally looked for it. I do know the type of attaching bracket that you refer to, to hold the kickdown cable. Also, if memory serves, there was an electrical connection down by the starter side of the trans, hard to see it 'cause it's right above the pan. It felt like a spade connection, so maybe a park/brake lockout?

Now, we might as well throw the accelerator linkage into the fray, just because it's all connected at the top. I previously posted that we were dealing with three distinct problems. I personally want to rebuild the old Q-Jet for the sole purpose of street driving. I need to go look at it and reference where and if there is a trans-kickdown bracket. The Holley that's on there seems to pump and meter fairly well, so we'll see if we can't use it for now. I finally got the secondary jets to open up by adjusting the linkage a lot. There are quite a few linkage points between the pedal and the carb, due to the old electric kickdown. Keep the ideas coming...

joe_padavano

A TH350 will have the provision for the kickdown cable just above the pan on the forward RH side of the trans, near where the cooling lines attach. The cable is held to the trans with a single bolt that goes through the flange in the cable sheath. There is an S-shaped hook that attaches the cable end to the spring-loaded valve in the trans body.

A single spade terminal electrical connector on a TH350 is simply a pressure switch connection that's used for the Transmission Controlled Spark system on the 70s cars. The purpose was to tell the emissions controls that the trans was in third. You can ignore it. If it's a four pin connector, your TH350 has a lockup torque converter.

Eighttime

Great! I'll keep you posted...