Hot-Rodding a Brat in two stages - Suggestions?

[RAD]

So... here is where this is at so far....

 

At least for stage #1, for the relative here and now, I am settled on sticking with the EA81 engine.

So far, the plan is to get a performance coil, such as ferp420 suggests to get more out of the gas I am already using,

and to get a much better carb to feed more fuel, in a more efficient way into the engine, which can be handled by the engine due to the performance coil giving better spark/burn.

Next is what else I can do....

I love the idea of a super-charger, but that is not for the here and now, and would be costly and very involved if and when I go that route. SO... After Turbo and Super Charger, that leaves the use of some kind of Ram Scoop or similar, to in turn force-feed more, denser air to the carb...

Other than presumed basics of using what amounts to a glorified air funnel, I know nothing about Ran scoops, so I will be looking this up, and would appreciate any further tips on improving power with such a set-up, and just how much improvement a ram scoop does make.....

 

Ram scoop is already making some sense... From a link....

 

http://ateupwithmotor.com/terms-technology-definitions/hood-scoops/

 

"As a rule, cooler, denser air will yield more power while warmer, thinner air (such as on a hot day or at high altitudes) yields less."

 

I am at moderate altitude, running on warm to hot days, with a hot engine in a hot engine compartment - and, to be honest, I am also running about the smallest air cleaner\filter there is, so in a way, I am suffocating my engine, the air it IS getting is thin and hot, and I am pushing it hard despite this. Seems like a recipe for poor performance anyway.. the question is how much increase in performance will a decent Ram Scoop add?

 

This leads to minor problem #2:

A normal height/thickness of air cleaner does not fit in my engine compartment, I have small dents, etc in my hood from this, and was considering a hood scoop just to provide room for it anyway.

 

The apparent choice is to either (1) Mount a ram scoop so when I close the hood, it seals with the carb well, and tolerances and clearances become the devil in the details. or (2) to mount the ram scoop securely to the carb, and cut the hood to fit around the ram scoop - simpler and easier in some ways, but may not work well with the scoop I have already been considering and have on hand.

 

Both of these options have to deal with the engine moving a little under torque, gear shifting, suddenly punching it, etc.

 

The bottom line is starting to look good though...
More/better air, more/better gas, more/better spark. That would have to have a real world noticeable difference.

 

Lightening the vehicle is also a concern that I must deal with. I carry a lot of gear with me, been slowly cutting down on that, but am starting to wonder what, if anything I can do as far as lightening the vehicle itself. Not too much to work with as far as that goes without compromising the vehicle's structural integrity.

In this vein though, the aim is to make the job easier on the engine. I have to start thinking about various ways to maybe do that....

 

 

 

 

 

 

 

 

Edited July 11, 2016 by RAD

[RAD]

This looks like it might work within my vertical hood clearance, despite that I want to use a Ram Scoop...

 

 

http://www.webercarbsdirect.com/product-p/wk730.htm

 

This, from weber redline site looks interesting....

 

"Footnotes:   

1. All three digit K kits are for racing and offroad use only and must never be used on the highways in California."

 

http://www.redlineweber.com/carb-kits/auto/subaru/

Edited July 11, 2016 by RAD

[ferp420]

thats a great carb exstremely reliable way better than any duel carb set up thats what im running on my vw bus it wont be much more power than stock though and less than fuel injection swap but combined with other mods it could do the trick with such low hp engine even 5hp would be a noticeable improvement and shouldent be hard to get new plugs a nice air filter and maybe a glasspack or performance muffler use senthetic oils in the trans and diff fresh bearing grease all the little stuff adds up high octain gas and the msd ignition lets you squese more timing out of it for alittle more kick i dont think there is alot more peak power to be gained but you can make more power sooner so its more drivable

[ferp420]

oh and the msd or multi spark distrabustion unit is not a coil its a electronic ignition distrabution box you need to use your stock coil and stock distributer set ups it goes inline with your stock electronics and trigers the coil to fire multiple times giving a more complete burn

[iluvdrt]

Hey RAM where at in Socal are you? I'm in Oceanside and can help. Before my lift and tires I could easily maintain the speed limit over the mountain going east and west on I8. And even with the tires and lift I can still drop into 4th and maintain speed. That's about the biggest and longest hill we have here on a highway. you can PM me for my number, Id love to help you out. Keep in mind, there is no cheap way to do this.

 

As far as the revs go, EA81 is made to rev high for long periods of time. Its an aircraft motor, hence the factory dual valve springs. Ive taken mine up to 7500 RPM's but really anything after 5K is pointless. 3-4000 RPMs is where is really likes to run.

 

Anyways, I have attached a pic of my work if you're interested.

 

 

[RAD]

oh and the msd or multi spark distrabustion unit is not a coil its a electronic ignition distrabution box you need to use your stock coil and stock distributer set ups it goes inline with your stock electronics and trigers the coil to fire multiple times giving a more complete burn

 That might actually be not so good newws, as I want nothing to do with any kind of electronic ignition, period. But I do at least need a better coil, mine is pretty beat up.

[el_freddo]

Hmmm interesting approach...

 

The ignition system is electronic, unless your dizzy is an acient unit with the old points system. If you mean EFI that's a different kettle of fish - and work well when the harness is cut down properly.

THE best bang for your buck with the EA81 is the EA82 SPFI imo. This will metre the fuel to be the best ratio at all times. The weber gives good performance but you can forget about economy from what I've heard about this conversion.

 

If you're looking at an EJ engine these are tops. Best bang for buck IMO. I did it to my L series many years ago and it's the best thing I did to it at the time. Don't be put off by electronics or cam belts! Do the electronics right the first time (with careful research and attention to detail) and you'll be right. As for the cambelt, replace at the given intervals with quality equipment and again you'll be set.

 

The EJ22 is a bit of an allrounder. Low torque and high rpm power. They'll happily rev high all day everyday. They're the ea81 of the EJ series engines

 

An EJ with the L series 5 speed and adaptor plate is a good setup for the MY or L's. You will easily spin front wheels, even with the extra weight of the EJ. It doesn't effect the front suspension that much that you need to do anything to it. Just make sure the suspension bushes are in good condition as you usually would.

 

The other best thing to do with an EA81 is a rebuild with a mild cam, especially if running the weber carb.

 

There are loads of conversions to read up on. I reckon you've got a lot more reading to do before you settle on your final setup.

 

Also the dual carbs will bolt on with their inlet manifold to the ea81, just that you won't get the full benefit of the EA81S block, heads and cam package. They're a very different setup to a "regular" EA81.

 

Cheers

 

Bennie

[RAD]

Solution - problem - solution...

 

Problems with carb were getting bad, had to do something, so I took the top section off, and found that (1) float was off - knew that. (2) the gasket was pretty ragged. (3) there were hardened gobs of gasket goop half blocking the main barrel, surrounding the jet but not actually blocking it. Got all that out but need an upper body / Top end / mid body gasket, and since everything else I'd good, and I am nearly broke, I want to find just that gasket, but can't find one in local auto Parts, only rebuild kits. I simply cannot spend that much right now, so unless someone has a link where I can get one, I may have to use "Form a gasket", though not the best choice, The Brat is down, on the street, and I need a quick fix. Already tried without a gasket, predictable fail there. Any sources / ideas?

 

I suspect once I get this solved, performance may improve, lol...

[DaveT]

I've never seen carb gaskets outside of a rebuilding kit. Finding form a gasket that survives contact with fuel may be tough. I never found any. Try looking for blank gasket sheet, to cut your own, but it's hard to find it thin. Maybe try heavy paper for temporary?

[TomRhere]

I have cut them out of cereal boxes in the past for a temporary fix.

Not an easy task to do either.

[turbosubarubrat]

I bought a big sheet of felpro gasket maker at oriely's which is rated for gas and i used it to make a float bowl gasket for a weber.

[Sapper 157]

Honestly your best bet is a rebuild kit...  if you can scrape it together, its only about $22 for one from carparts http://www.carparts.com/details/Subaru/GL/Walker_Products/Carburetor_Repair_Kit/1984/WKP15853A.html

[ferp420]

gaskets are easy to make you can buy gasket paper but thin cardboard doses just as good if your good with sissors i use lined paper to make a rubbing then transfer it to the gasket material and i use alittle layer of silicon just to seal any poors i hate buying gaskets ive been making all mine out of copper because its free my freind owns a sheet metel shop and has alot of waste copper i know its exspensive if you have to buy it

[Sapper 157]

gaskets are easy to make you can buy gasket paper but thin cardboard doses just as good if your good with sissors i use lined paper to make a rubbing then transfer it to the gasket material and i use alittle layer of silicon just to seal any poors i hate buying gaskets ive been making all mine out of copper because its free my freind owns a sheet metel shop and has alot of waste copper i know its exspensive if you have to buy it

I would be hesitant to use silicon on a carb body gasket... it would be too easy to block up a pour or passage way... I do use a tiny bit on the base gaskets to help seal the mating surfaces, but on the carb body I dont believe that would be necessary. Now, as far as the base gaskets are concerned, absolutely use gasket material. it is way cheaper than buying a bunch of premade ones.  

Edited July 19, 2016 by Sapper 157

[BratWarrior]

I might have some spares I can send you. I'll go through my carb stuff tonight.

[BratWarrior]

Is this the gasket you need?

 

[superooo]

I have a rebuild kit for a hitachi, dont know if anything in that would hlp u

[DaveT]

I my early days of car repair, I discovered that silicon and other gasket maker stuff is dissolved slowly by fuel.

[RAD]

Here's an odd thought - Instead of my dual carbs dream, what if I put a non-subaru larger carb on, larger than the popular Webers? What if I could get or make an adapter plate for a small 4 barrel carb from some other performance-based car/engine?

[RAD]

Likely in the next 3 months, I will be looking for a mechanic to do an engine swap for my Brat.
I will be in the Lake Elsinore, CA area, and otherwise in the San Bernardino / SoCal area in general.

Any and all suggestions and offers are more than welcome.

[DaveT]

A carb has to be sized for the air flow range CFM that the engine can draw through it.  Thus, the sizes of weber carbs mentioned by those who have done the swaps are the ones that will work best.

 

These engines are mostly limited by the airflow paths in and out of the heads, and the small valves, from the many discussions I have read over the years, by those who have attempted to modify them.

[ferp420]

One thing I've learned with modding my ea82 Is they don't like it when you add extra fuel I don't know if the ea81 is the same but I'm guessing it is

[iceageg]

I just recently picked up an 86' hatch and am planning my way down what I think is a very similar path to what you are hoping to accomplish.  If you are dedicated to staying with the EA-81 platform then the multi-spark ignition unit and a weber carb will be your best friends.  Magnaflow makes direct bolt on exhaust parts for the brat/hatch as well.  All three of those together probably won't add up to the benefit a D5MT would give you.  Even better if you paired them all together.  A bigger carb will only work if you feed the engine more air and that's where the effort and expense starts to rise dramatically.  You are talking about a bigger cam, headwork, forced induction or some combination of them.  As someone mentioned before the EJ-22 conversion starts to make alot more sense when you start to look at the cost and effort of the two side by side.  Especially when you look at the end result.

 

All that said, my preferred way (and current plan) to get around the "alot of effort" constraint is to source an engine and start early.  Put it on a stand and get it as ready as possible to drop in when the old unit comes out.  That way it's ready if something does go wrong and you don't have to rush to rebuild the engine you took out just to get back on the road again.  If I can source a good EA to start with I will likely stick with that just for simplicity.  EJ's are a dime a dozen in Colorado yards though, parts are plentiful and aftermarket support is huge so I may build one of those carburated instead.  Either way it will end up supercharged.  May even toss one on my existing EA-81 before the swap just to add it to my list.  I don't know how far you have got into your "stage 2" planning but remember that bigger isn't always better.

[Uberoo]

I'm kinda late to the party but with ea81's a weber 32/32 carb and a half way decent exhaust will work wonders.That and do not fear the rev limiter.Back when I still ran ea81's I would cruise down the street at 3.5-4K with shifting at 4k if i wanted MPG,But thats not fun.With the weber and the exhaust it would have no problems spinning 8500 rpm  even with over 300K on the clock.There are two things that will kill an ea81 at that RPM; lack of oil and ingesting large quantities of water.Found out the water bit on one of my mudding trips-its not a good idea to go through mud/water up to the hood with no snorkel while spinning 8000 RPM.Bent every pushrod and one or two connecting rods.

 

The sound the engine makes at 8500 rpm on the other hand is quite frightening.Subaru people that know what the engine is capable of with good oil pressure just stick our fingers in our ears and laugh,The unenlightened however jump off the sidewalk in fear.