3 cylinder stacker!

[lucas_chrysler_1]

hi guys, ive decided to take on my next redneck project, and create an engine never ment to be. I am going to make a 75hp CHRYSLER into a stacker engine (dont worry no real stackers will be harmed) i am using a stock exhaust cover plate, and planning to drill 3 holes large enough for exhause then make the 3 pipes that come out the side of the cowling. i am going to square up the transfer and exhaust ports (not going to change timing unless some one explaines propr incraments) should i put in seperator plates to keep the 3 cylinders seperate from each other? or should i keep it open up to the exhaust plate? thanks, im hoping its realy loud. and i know i will have to enrichen my carbs what are the benifits/dissadvantages of this? hp gains/losses? any input is appreciated

 

[jerryjerry05]

Re: 3 cylinder stacker!

Look through the older post as someone did this about a year or so ago.
It looked different with the stuff comming out the side.

 

[Frank Acampora]

Re: 3 cylinder stacker!

ANYONE can do it the "redneck" way but if you do it right, you will really have something

If you are careful with porting and port both bypass and exhaust, then you can expect about 5-10 horsepower gain per cylinder. These gains come at higher RPM so you need a 2 to 1 lower unit and a slightly smaller diameter but higher pitched prop. Your 75 has small exhaust ports timed differently than the 85-90 so if you do square them, to realize maximum gains you must also elongate and enlarge them. See if you can't get your hands on a junk 85 block to compare ports.

Because the exhaust ports open for about 120 degrees and the crankthrows are 120 degrees apart, there is no open overlap and it is not necessary to isolate each cylinder using stacks. Although, if you do use them and "tune" them you will gain additional horsepower. If you do your homework, (which I never wanted to do) You can compute the correct length for the pipes AND unless you want the noise, you can design the pipes with a smaller outlet which will muffle noise and reflect the pressure wave back to the ports. Of course, if this is your goal, then you must isolate each cylinder. Older four cylinder racing Chryslers had two open pipes tuned to reflect pressure waves back to adjacent cylinders which fired 180 degrees apart. A special water cooled exhaust manifold was used.

If your Chrysler is an older one with a two piece lower unit, you will gain about 3 MPH by mounting the powerhead on the newer Chrysler or Force one piece midleg and lower unit.

Again, if you have an older Chrysler and speed is one of your goals, then swap out the stock ignition for Mercury electronic-- It's a lot like building a custom hot rod: Find the parts and adapt them to your engine.

Remember that inside the exhaust cover there is a stainless steel plate and it always warps with heat. Your pipes must also pass through this plate while still sealing water into the cover.

So again, if you absolutely want pipes, you must do the research. But after that comes the fun. And you won't believe the noise. Neither will your neighbors.

 

[lucas_chrysler_1]

Re: 3 cylinder stacker!

i do have a 85hp block laying around. so to get maximum gains i guess i will use the 85 block. what does the iner stainless steel plate do? i know water flows down the back, but is i were to put this back together with out it what will happen? and why swap to mercury electronics? what gaings do they have? thanks!

 

[Frank Acampora]

Re: 3 cylinder stacker!

Leave out the inner stainless plate and water will spray the bottom of exhaust chamber. None will ever get to the block. You can NOT run without it or something else you engineer.

Mercury ignition was superior to the old Chrysler electronic and the racers used to swap them into their engines. They did this primarily to eliminate the distributor but it still was better than the distributorless Chrysler/Prestolite electronic ignition.The later Mercury ignition as used on Force engines is also better in that it has a real rectifier.regulator and has a better magnet arrangement on the flywheel with stronger magnets than the old flexible magnetic strip glued to the flywheel. The stator is completely sealed and therefore more trouble-free

 

[lucas_chrysler_1]

Re: 3 cylinder stacker!

ya i know the later forces had the merc ignition. i have 2 possible engines as candidates. a 1988-89 force 85hp (bigger pistons) (unmolested,) or a 1970 chrysler 85hp(smaller pistons), it looks like it has been ported on the exhaust side becasue ports are squared up, and they dont look like they are exactly perfectly the same. which block is faster. i was thinking of using the 85 chrysler as a test pilot. then if it works out move up to the 85 force, and improve with the merc electronics and prop it accordingly. no matter which block i decide to use it will be with a one piece lower unit and i will have trim tilt. realy all i want is a loud motor, power gains would be nice though. i have a pair of real racing stacks i was thinking i may be able to copy. but i think im just going to wing it and make up as i go along. any aluminum that needs welding i can bring to school and weld. as i have 3/16 aluminum i can fabricate with. what would happen if i made just a flat plate that fits where the origonal exhaust cover went?

 

[lucas_chrysler_1]

Re: 3 cylinder stacker!

do happen to know where it is?or have a link for it? thanks.

 

[Frank Acampora]

Re: 3 cylinder stacker!

The flat plate is a difficult one to answer because it's been a long time since I examined water flow in these engines. Basically, if you block off the chamber where the water enters, it will flow up and then around the cylinders. However, I don't remember the flow to the rear chamber by the head. So a flat plate may work, but at the place where you weld on the stacks, it will get red-hot.


Are you saying that you have a set of Chrysler racing stacks for four cylinder engines?

 

[lucas_chrysler_1]

Re: 3 cylinder stacker!

i was thinking a bout just taping and pluging the holes in the origonal plate too. i was going to plug the holes, put it back on the motor and check the temperatures and see if it is running too hot or not. ya i expect the stacls will get nice and warm . I will upload pics with my progress, and a video of what it sounds like, it my camera picks up the sound.lol. and I do not own the 4 cylinder racing stacks, But i do have access to them (my friend who is a chrysler fenatic as well) we are plannig on building a real racing motor. but i like to make things custom, and something different so i wanted to try a 3 cylinder stacker. thanks