keep the carter yh or replace with a pair of rochesters or?

[ironbruuu]

Hi Folks
I have a 1964 monza coupe that has been sitting for a while. I currently have the carter yh turbo setup which starts buts runs terribly and if I stop after a drive it does not start. Go for a short walk come back it starts. The car does have good power even if it is running rough, but get the revs into the >2000 rpm range it stumbles.
Here is short list of what I plan to do and advice wanted and appreciated

-Replace points with electronic
-Replace fuel filter
- Clean or replace gas tank. ( From what I understand no in car proper cleaning..so I guess the tank is coming out)
-Fuel pump stay mechanical go electric what's best?.. any tips or how to's ?
As I have no idea of the condition of the turbo and carter as they have been sitting for a few years. I was lucky enough to have a very knowledgeable corvair enthusiast come and look at my car. He suggested I convert to dual carbs that would get her on the road in the simplest manner and then I would be able to work on any other kinks as I find them that and if I want to have the turbo set up It can be rebuilt and installed at a later date.

Thanks in advance for any input.
James

[bbodie52]

It is unlikely that your turbocharger is internally functional, and as I mentioned earlier putting it in the hands of an experienced Corvair turbocharger technician for a complete teardown and inspection will help you decide on the next step. I would have the turbo inspected prior to spending any time or money on the carburetor. If you decide to overhaul the turbocharger you can discuss your carburetor options with that same technician and then move forward with a carburetor rebuild or replacement. The condition of the distributor and pressure retard device will also have to be confirmed, because these elements are a critical component of a turbocharged engine to keep it healthy and running well. And if you do return the engine to its original turbocharged running condition, more-expensive Premium gasoline will also be an essential component.

You should also run a compression test on all cylinders to determine the mechanical condition of the pistons, rings, valves, etc. This will help to determine the mechanical state of the basic engine and whether or not it is sound enough to remount an active turbocharger. You can certainly mount a pair of standard carburetors on the engine in place of the turbocharger, but you will also have to obtain the associated vacuum balance tube, associated carburetor linkage, air cleaner and PCV assemblies. The end result will be something close to a 110 hp engine, with the same camshaft as a 110 hp engine but with a lower compression ratio. The engine would probably produce about 100 hp and would run fine on Regular gasoline.

95 hp Engine: 8.25:1 Compression Ratio
110 hp Engine: 9.25:1 Compression Ratio
150 hp Turbocharged Engine: 8.00:1 Compression Ratio

The centrifugal advance curve and pressure retard found on the turbo distributor is quite a bit different than a normally aspirated engine. If you substitute a pair of standard Rochester carburetors you will need to consider changing to a standard distributor also. In addition, the heat actuated automatic choke mechanisms are not present on the turbo heads, so you would not have any way to hook up automatic chokes on standard carburetors unless you buy the choke mechanisms and install them on the turbo heads.

As you can see there are a number of small elements you would have to obtain to detune the engine to become a normally aspirated engine. You might want to have the turbo inspected first to do some cost analysis on bringing the intake system (turbo and fuel system) up to par, before you jump into trying to obtain the parts you would need to revert to a normally aspirated engine.

You have what looks like a nice and very rare Canadian-built Spyder. If you want to retain that unique classic in its turbocharged Spyder configuration, you will have to determine the mechanical condition of the turbocharger and engine, and then decide if you want to proceed with restoring it to its original state or spend the money to detune it to produce a drivable vehicle a little-more quickly. If the engine turns out to be mechanically sound, rebuilding the turbo and carburetor might be the best way to go, instead of spending funds on the other hardware needed to produce a running normally aspirated engine.

See the following for guidelines on removing and replacing your fuel tank...

Fuel Tank Removal & Installation

viewtopic.php?f=225&t=5779

[Scott V]

Fuel pump stay mechanical go electric what's best?.. any tips or how to's ?
As I have no idea of the condition of the turbo and carter as they have been sitting for a few years. I was lucky enough to have a very knowledgeable corvair enthusiast come and look at my car. He suggested I convert to dual carbs that would get her on the road in the simplest manner and then I would be able to work on any other kinks as I find them that and if I want to have the turbo set up It can be rebuilt and installed at a later date.

a mechanical pump is ok. 2 things to check before installing it. make sure the check valves are staked & check the large spring to the stock spring. alot of springs in the new pumps are too stiff that that gets you too high fuel pressure. cut the spring shorter if its too stiff.

if someone has a set of rebuilt carbs/linkage/carb studs that you can use - that maybe the simplest thing. you will need the accelerator rod also.

if you need to rebuld the 2 carbs or its going to cost you some $$ to get the carbs & other parts - id just rebuild the carter yh & go from there. when you pull the carb you can give the turbo a quick check just to see if it is stuck or turns free. turning free doesnt mean its ok - it can still have problems that need to be fixed.

-Scott V.

[Jerry Whitt]

You noted that a no start condition exists after running for a while.

Do you mean "No Crank", meaning starter motor does not spin the engine, or do you mean "No Fire up" meaning the starter spins the engine but does not begin to run?

[miniman82]

I had nothing but trouble with mechanical pumps, save yourself a lot of headaches and put an electric one under the tank. Save yourself hair tearing out by getting rid of the YH, and put a Weber or SU in its place. After that, put a programmable ignition or Safeguard in the car. Only then will it begin to function like a modern car, with performance to match.

[Nickshu]

The YH can work well but is very sensitive. All ancillary things must be sorted properly too... Turbo, vacuum leaks, fuel pressure, etc. Do you have the Bob Helt book on the YH? Essential.

Also you say your car is a Monza. Not a Monza Spyder? Was it a turbo transplant? Or do you know if everything is original and complete?

Sent from my SPH-L710 using Tapatalk

[bbodie52]

The car is a Canadian-built 1964 Monza Spyder coupe. However, the pictures show that the oil feed and drain lines have been disconnected, so the condition of the turbocharger is unknown and I'm assuming the impeller and turbine are frozen in place since there is no turbocharger lubrication.

[miniman82]

Jeeze, that thing is toasty for sure. Who would do such a thing, think it was leaking so they 'fixed' the leak by removing the oil supply? I don't want to even imagine what the inside looks like, the bearing is probably welded to the turbine shaft by now...

[flat6_musik]

I was wondering......if the turbo exhaust is intact, or if the previous owner may have installed a standard Y-pipe and bypassed the turbo. Hopefully, he did. Ironbruuu, maybe you could jump under there and see.....

By the way, you're going to need some rubber boots around those spark plug wires also.......

[ironbruuu]

Hi Guys
Thanks for all the input and advice. I am going to take off the turbo this weekend and see what else I can remove for inspection, while I am at it. The car does have seem to have all the "turbo" bits such as dist and advance .
I have taken some extra pics and will post them. Stay tuned :)
cheers
James

[ironbruuu]

Turbo Serial 43973
part number 3856709

[miniman82]

First thing is figuring out what state the turbo is it, I would decide if it is repairable first before spending money on de turboing it. In the end getting the original system up to snuff might be the most cost effective way, but I need to see what condition the turbo is in first. Hopefully it didn't have exhaust going to it while the oil lines were off, that is a recipe for disaster.