Intake

[ninjaman123]

I have a 1989 GMC Pickup with a 350 c.i engine. Where I live it is very cold sometimes, and my truck runs WAAYYY better when it is warm outside, regardless of whether or not the engine is warm. I was wondering, could I build some sort of intake heater using a old dirtbike radiator mounted to the intake where the cold air is ran through the radiator, with the engine coolant ran through that, before it is cooled by the main radiator?

 

[leroys1000]

If it is an engine with a carbuerator,warm the engine up,turn
it off and make sure the choke is opening all the way.
Is the engine temperature running cold?
If so,it is possible the thermastat is not functioning properly,
is stuck open or has been removed.
Cold air will usually provide more power as it is denser and
there is more air to expand inside the cylinder.
A fuel injected engine usually adjusts the fuel mixture,but there may
be an air flow control on the intake.

 

[ninjaman123]

It is a fuel-injected throttle-body. Temperature never gets above about 150 degrees. Put a new thermostat in it last year when i did the water pump and alternator.

 

[ChRoNo16]

Assuming vacuum lines are all good, when is the last time the throttle body gasket was done? Those normally went bad on the Chev/GMC's with the 350 (Previous owner of 3 of them) and they arent very expensive, and the throttle body only has like 2 bolts in it.

 

[Elvandil]

In Vermont, when we don't get enough heat from the engine due to cold, or just to raise the temp in Winter, all we do is put a piece of cardboard over the front of the radiator. Sometimes, it's all right to cover it completely, if it's cold enough, or just cover half if the engine gets too hot.

It seems bit strange to try to heat air that is used for cooling, anyway.

 

[ninjaman123]

I have never put a throttle body gasket in it. Im getting ready to put a stage 3 edelbrock intake manifold on it.

 

[leroys1000]

Gaskets where the manifold meets the head should be the same for both.
They just set along the intake side of the head.
You just need to be careful to set the manifold straight down on top of them
so they don't move.
Some engines use a 1 piece,sheet metal valley pan.
Those are a bit easier to deal with.
They should also sell a higher temperature thermostat that may help
with the cold running problems.
Ran across this the other day.
Might be helpful.....
http://slickdeals.net/f/3718004-Free-Chilton-library-all-cars-online

 

[ninjaman123]

I'm not actually having problems with it, its just that it has less power when the air is cold. maybe it has something to do with the expansion of pistons when hotter? Btw it has half a million miles on it.

 

[leroys1000]

Probably some piston ring blowby then.
A higher temperature themostat can help.
A lot of people use them in the winter in cold areas.
Lets the engine run warmer.
Then go for a colder one in warmer weather.

 

[ninjaman123]

Could I put new rings in it to fix this also? Or just have to put pistons and rings in it

 

[leroys1000]

You would need to get the cylinders checked to see if there
is enough stable cylinder wall left and maybe have them bored
a little bit to clean them up and make sure they are still round.
The lip that is left at the top of the cylinders by wear would need
to be removed.
Then you would need a rering kit for the new cylinder size.
Considering the amount of work that would go into it,it would be a
good idea to have the crankshaft checked and ground if needed
while everything is apart.
Then for the rering kit,you would need rod,crank and thrust bearings
to fit the new,ground dimensions.
So you need the machine work done first so you know what the
dimensions of all the parts are for the rering.
It is possible to just swap rings if you think all the bearings are
still tight,but it's not recommended.
You have to make sure all the piston bearing end caps go back
on the same connecting rods in the right direction.
The old pistons are probably fine and would need to be cleaned up.

Honestly,with that old of an engine,a complete rebuild is probably a
good idea,as there is probably some good wear on the valve train
as well.
If it is a good truck and you want to keep it for a while,it may be worth it
to check out some shops and get estimates.
Be prepared to be looking at around $1500-$2000 or so though or
around that.
Mechanic prices aren't what the used to be.

 

[ninjaman123]

I can do it all myself I have all the tools I just have to have it sent off for machining. If im going to tear into it that bad Ill turn it into a 383 stroker.

 

[leroys1000]

Yeah,trying to do a basic rering with the engine still in the vehicle
can be a pain.
I did it once and it ran fine for a while,but turned out I had one of the
end caps on backwards and spun a rod bearing.
Had to have all the machining work done anyway.
After I got it all back together and running again,me and my girlfreind
broke up.
It wasn't a week before she was driving drunk and totalled the car.
She was alright,but that was a waste of money.
If your engine has never been rebuilt,there should be no problems
rebuilding it.
You could just take it in and have a compression test to get an idea
if you are losing pressure or not and how much.

 

[ninjaman123]

Yeah its never been rebuilt. I will probably just build the 383. Would be a fun project. Sucks what happened to your car.

 

[leroys1000]

Yeah,working on engines is cool.
It's ok,it wasn't my car,it was hers.LOL