Thread: Engine Placement

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Well im at the engine mock-up stage of my 30 model A chassis build and im wondering if there is a rule of thumb for front to rear placement? Is there a good measurement to use? Say from the front of the water pump to the radiator or something like that? Any help is appreciated.

Seanpd

Seanpd i too am doing the same . I have a 31 Model A sedan and I'm useing the 302 and its about 2 inches longer then a sbc . Thats why you see them in most apps. My 302 is going to be a chore but its going in . I have a theme of Ford in a Ford . I'm also pulling some pedals out a 94 mustang to allow cable clutch and power brakes .

You need the radiator and some what of a fan thickness dimension . Measure your block and water pump and plan on about 3/4 inch clearence for this measurement. I placed the radiator in and marked the frame . I then added the thickness for a electric fan allowing 3 inches as 2 1/2 inch thick fan at the motor is the thinnist i seen . Mark off your fan measurement . You now have whats left behind to install which ever engine you decide. The amount of firewall recess and leg room will be up to you.

I'm looking into a short water pump with pulleys that will shorten my block they say a total of 2 inches. This is alot of room to gain in a Model A with a 302 .

Previous owner over cut the firewall must have been thinking big block . but it works since it give me more room before i fill it back in .

The white cardboard circle is my possible mock of booster but i see there is plenty of room and i like this instead of below the floor .

I put a 302 in two Model A's. I did not go to the short water pumps. Used stock fan in both. To save some room, I put the fan on without any spacer - it just cleared the lower pulley. I think that no matter what you do, you have to cut the firewall. Good luck

Paul how far did you recess your fire walls . This app with a rough estimate looks like a 5 inch .

My '27 is on Model A frame, and running a sbf I had to recess the firewall 4 inches. Even at that, things are tight at the radiator, so when I redo the car I am going the short water pump routine.


Don

Don great info . The company that makes it wants $300 for it but its a good deal considering the help it gives in room savings

For a low-buck firewall recess, use a shallow wheelbarrow tub.

Seanpd, to further expand on answering your question, there is no hard and fast rule for where an engine goes, but generally you position it so that you have adequate fan/ radiator clearance, and clearance at the rear for valve covers and/ or distributor. Usually the radiator is in a fixed position because it only looks good if centered on the axle or behind it, so you are left to contend with the firewall, and as others have mentioned, you do this by recessing it. Techs idea about the wheelbarrow tub is a good one, and they have been used a lot to solve these problems.

What you need to do is bolt your radiator on, slide the body back a little, install the engine and tranny, get your radiator clearance (make sure you have the actual accessories, fan, pulleys, etc you will be using) and then figure out what you need to do to make the body fit. Steering clearance also comes into play here.

You also want to set your tailshaft down angle at this time. Generally about 3 degrees is good. Some people put a level on the carb base, but that has never worked for me as my intakes seem to always be much different than level when I set the 3 degrees up. Not sure why, but they work fine anyway.


Don

Also depends on what you want the car to do and what you are building it for. And also on how much you want to sacrifice leg room inside the car. I usually scale mine as the build progresses and prior to starting the build I know what the car is going to be expected to do and try to set the front and rear weight accordingly. A car with the engine as far forward as possible will afford you more interior room, but will comprimise the front to rear weight and leave the back end a bit light for handling. A car with the engine set back a lot will be closer to equal on front to rear weight distribution, thereby handling better, but leg room and interior comfort will suffer....

As all have said recess is a necessity. I have the engine and trans in and i need to move it back a little more. It's just hanging on the hoist . The fan blade with out spacer will not work on this belt drive so i will be yard hunting for a little different pulley set up . The sedan i can move the seat mount rail back and still get long water pump in . This might not work on a coupe model as easy .

Where it sits now the bell housing is just coming into floor area where its starts to angle. The hump i think will be very minimal. so i see there is still plenty of room to come back a few inches

couple of pics if that helps .

Thanks Bluestang67 for the info. I was in ahurry when I wrote my thread and forgot to say I've stretched the frame 4 inches in front of the firewall (oops). I'm going to run a 302 Ford in this car too. An AOD with mustang EFI should run good and reliable. I will put AC on the car as it is going to AZ when its done so my dad will stay nice and cool in the summer. I'll post some pics as soon as I figure out how. Thanks again to you and everyone who responded.

Seanpd

Well, if you don't mind a bunch of fabrication work, just put the engine where you want it (way back) and enjoy the improved handling and performance!!!!!