What is the point of having the cooling fluid run through the carb spacer? I am probably wrong but isn't it better to keep the fuel cool?


Also I have a relatively stock 390GT, all I know about the engine is its bored .030 over other than that I have no clue if it has a stock cam or an aftermarket.
What is a good size carb to stick on it, 600, 750cfm? I am guessing Holley is the preferred carb for Fe engines.

Thanks Jason

 

The heated carb spacer prevents icing in cold weather and warms up the engine faster. The 390GT motors came from the factory with a 600CFM carb. Fords Muscle parts book tells you to use the 428CJ carb for hot rodding. This a 780/750CFM unit with flared booster venturies to drop CFM to 735 (the boosters really help the throttle response). But I tried running a 780CFM, 3310 carb on my stock 1966 Mercury Cyclone with a 390GT motor and it was slower at the track than the stock 600. This was after about 20 hours of dyno time, tuning the damn thing. I worked at the shop and did the time after hours and it was a perk of working there, the own was a racer and understood.

 

Thanks for the reply.

Is it better to use the heated spacer or a newer style like a phenolic(sorry the spelling is probably wrong)?

Jason

 

Winter time it helps, as does the thermal air cleaner. If you haven't changed out the 2V by summer, just by-pass the spacer.

 

Actually the spacer helps low end torque. Leave the spacer and use a hose to bypass the space (not have the water/coolant flow thru it).

 

My 75-360-T18 is basically stock but I did replace the original spacer with a different aluminum one and I increased the size of the internal passages to increase flow back and forth through it when it's idling. Also added another thick cardboard gasket so there is one both top and bottom of the spacer.

Seemed like it improved the idle opening those passages. (?) :)

And that extra gasket wasn't helping much sitting in a box. ;)

I don't know, but guessing the higher flow back and forth through the spacer cools the spacer-block and warms the mixture?

What do you think?

Alvin in AZ (the freak with no choke)
http://www.panix.com/~alvinj/file12/choke.jpg

 

The reason I was asking about the spacers is because I don't have a carb spacer yet. I plan on getting one and I was trying to find out which one is best to use. I have read that a 4-hole spacer is better than the open square kind, I think its better for low end power.

Jason

 

What engine are you looking for a spacer for? Be aware that stock FE intake manifolds had an exhaust gas passage that comes up next to the carb mounting flange. This manifold requires a special spacer to cover the exhaust gas passage. Standard aftermarket spacers are not wide enough to cover the hole. You could cut a piece of steel to put under the spacer to cover the hole. Just an FYI.

To see what I'm talking about chec out this thread post number 16, 3rd picture.

https://www.ford-trucks.com/forums/5...-on-fes-2.html

 

Correction: SOME FE mainfolds have the EGR that comes up next to the carb flange. Actually very few had this feature.

 

Probably true. FE production goes back to the 50s. So I imagine there's hudreds of thousands of intake manifolds produced without EGR. I would expect that these manifolds started on cars in the late 60s and then were used up in trucks at the end of the FE production. I mean, why even put this manifold in a truck engine that doesn't require EGR? Unless it's all that was being made at the time.

 

All the fe's I've run across need a 1" spacer under the carb.Depending on the climate you're in, leave it or remove it. Personaly,cleaner is better on trucks, just remove the hoses,instant clean. Then just use the heater as the 1" spacer or opt for an aftermarket version...cleaner yet! Use a spacer that insulates against heat if you still have a cast iron intake, it will help prevent "boiling" in your carb. Thick gaskets can also help against this. Aluminum intakes displace heat faster and also help with this.A-A-n-nd...unless you need extra plenum volume for high revs,go with or stick with the 4 hole spacer for better low-end throttle response.

 

I have a 68 390GT that I am putting in my mustang. It has the stock Scode 4 barrel intake on it. If I use an after market spacer what would be a good one to use?

Thanks Jason

 

The phenolic (I'm not sure of the spelling either) spacer is good, but beware the plastic look a like version, they like to warp like the vortec manifolds...once, and done. I found one at the speed shop that is made out of some sort of composite like fiber glass...it kinda looks like wood. And of course the smart *** that I am, that's what I tell people it is. brand names I don't know...it seems some people are a little too proud of their product for my wallet. Watch the port size on the spacer,smaller won't clear the butterflies,too big and get turbulance and loss of vacuum signal. does this help?

 

Yep thanks for the reply.

I was thinking of gettinh a one inch tall spacer.

Jason

 

Cool thread. :)

I ran mine without a spacer one time... it ran bad! :/ (70's)

EGR hole? ...pipe tap, permatex, cast iron pipe plug, little hand grinder...

Alvin in AZ