old school TBI engine build

[kwiksilver]

Some friends of mine have become involved with 24 hrs of Lemons http://www.24hoursoflemons.com/ which basically is endurance racing old clunker cars on a fairly strict budget and some sort of silly theme.

This years entry is an 86 Reliant Wagon with 2.2L TBI engine. The car was purchased from the original owner, a 96 yr old woman, with 79,000 miles. All that was done to it was install the race safety equipment and give it a Ghettofabulous paint job.



So half way through the Race the front cam seal popped out and it was pretty much all down hill from there, eventually the engine developed a deafening low end knock and lost most of its power.

I have been asked to build a "Racing" engine for this car. What I need to know are some tricks for beefing up the TBI engine for reliability. Since we are on a fairly strict budget, we are not looking to throw a bunch of high dollar parts on this engine, Nor are we interested in making huge amounts of power. All we need is a durable, reliable engine that can endure some beating on and keep going.

Keeping in mind This is NOT a turbo car, What are my best options? should I rebuild the original 1986 2.2L engine or look for a used, later model 2.5L engine to rebuild? would the stock engine computer be able run a 2.5L? what engine block/cylinder head combination would offer the most power, engine oiling and cooling reliability? what are simple and inexpensive things I can do to increase torque and HP with in reasonable levels? what would be the best cam choice for power? what are things we can do to impove the exhaust? (converter is being cut off this week)

Your Ideas, comments and insight are welcomed

[shackwrrr]

2.5 crank, Turbo rods, 2.5 TBI pistons. Head milled, deck milled, port/polish, better valve springs, Turbo downpipe, mopar headgasket, and an oil accumulator made from an old fire extigusher.

Pretty much everything is free or really cheap from the junkyard.

[shadow88]

Oil pan baffling with possible windage tray and lower inlet tube.
Mod the tbi manifold to accept a 2.25" flange from the neon and open up the "collector" area. It's terrible in there!! By open up, I mean cut it out and add in a pipe, not a dremel.
Lose the tbi system for a carb about 330 cfm.
This is what my freind did with his daytona he runs in mini stock class and it's competitive with the 16 valve cars.

[kwiksilver]

2.5 crank, Turbo rods, 2.5 TBI pistons. Head milled, deck milled, port/polish, better valve springs, Turbo downpipe, mopar headgasket, and an oil accumulator made from an old fire extigusher.

Pretty much everything is free or really cheap from the junkyard.

Good info... how much can the head be milled with out causing problems? will the turbo down pipe bolt up to a TBI exhaust manifold?

---------- Post added at 09:34 PM ---------- Previous post was at 09:32 PM ----------

Oil pan baffling with possible windage tray and lower inlet tube.
Mod the tbi manifold to accept a 2.25" flange from the neon and open up the "collector" area. It's terrible in there!! By open up, I mean cut it out and add in a pipe, not a dremel.
Lose the tbi system for a carb about 330 cfm.
This is what my freind did with his daytona he runs in mini stock class and it's competitive with the 16 valve cars.

good Idea on the carb swap, I suspected that might be the way to go. can we use the TBI intake and mount a 2bbl carb on it ? or do we have to get a new intake manifold?

[shackwrrr]

Ill have to look at my mopar book but I think .010 was taken off at the factory on the HO Carb motors and you can take more. The head can be milled a lot actually but tensioning the timing belt becomes an issue.

[kwiksilver]

I guess .010-.015" would be reasonable and give a nice bump in compression.

you mentioned using 2.5L crank and 2.5L pistons... are you saying to install them in the original 2.2L block? is that possible? what machining is involved?

[Vigo]

I would absolutely upgrade to a later 2.5L. It really doesn't matter which one you get, so any 86-95 2.5L non-turbo will do. Dont get a turbo motor because the lower compression will take away HP you really cant afford to lose. The 86-88 2.5 has the minor, minor advantage of still being able to run a mechanical fuel pump on the block if you want to run a carb.

I really dont think the rods matter for your application. Dont rev it past where it makes power (i.e. over 5000 rpm is pointless) and you'll never even approach any kind of limits on ANY stock rod.

As for what to do to the motor, i would focus on making it live first. Get an oil cooler adapter and run a cooler. Remove the balance shafts (gives you a little oil pressure boost / margin for error) and use the space in the pan to build some walls so the pickup NEVER runs dry in a turn. Keep in mind, if you run a 2.5 pan with no balance shafts and no walls, it WILL starve in turns. The upside of running the modded 2.5 pan is it holds more oil vs a 2.2 pan, which is good for a 'race motor'. hehe. If you CAN build an oil accumulator a la Accusump, i definitely would. It'll give your driver enough time to get out of traffic if something goes wrong, without ruining the motor. Id also wire a large, bright light to your stock oil pressure light. Something right on top of the dash that you cant miss. I'd also run a 160 degree thermostat and a manual fan switch. Other people who have run lemons with these motors have had success with high-viscosity racing oils.

As for performance, there's a couple of things i'd do to a 2.5 tbi/carb motor. Remove the coolant lines going to the bottom of the intake manifold. From a turbo exhaust, use the downpipe and the stock 90 degree bend in front of the fuel tank to do a simple 2.25 or 2.5" side-exit exhaust. I dont think you'll gain anything from going bigger/better on a stockish n/a. Run 14-16 degrees base timing. If you want to run 93 octane fuel you might be able to get away with as much as 20. You'll just have to try and see (be sure cam timing is correct first). Mill the head as much as you can without screwing with timing belt tension (i dont have the numbers, sorry). With either carb or tbi, you'll want to build a spacer under it to increase plenum volume and ease the turn from the throttle bores into the runners. On a carb intake you would ideally build this between the intake mani and the carb 'adapter' as opposed to between the adapter and the carb. On the tbi you'll have to modify the intake manifold itself to build an effective spacer because the intake has a hole in it the size of the throttle bore that would have to go. On a tbi you can do basic fuel tuning by using an inline fuel pressure regulator or 'crushing' the regulator to raise fuel pressure (cant lower it that way, though). If you dont want to hook a wideband 02 sensor up temporarily for tuning you can still do ballpark fuel tuning just by putting a voltmeter on the stock o2 sensor.

If you wanted, you could build a rear-facing airbox and cut out a section at the top of the firewall for cowl induction. This gets you outside air and feeds from a high-pressure area (once you're going fast, anyway). Or you could just go up and cut a hole in the hood.


Are you looking for suspension ideas as well? There are some pretty cheap tricks you can use there..

[kwiksilver]

Vigo, thanks... I was hoping you would see this post and respond. Very good information.

[Reaper1]

This is going to be an N/A build. No need for heavy stuff!

2.5 simply because there's no replacement for displacement in N/A. Use the lightest rods you can get your hands on (old carb 2.2 rods I think). Get flat-top pistons. TRW USED to make them. Swap to a carb manifold (MOPAR performance used to sell these, and there are a lot of old ministock guys out there that still have them). Hooker used to make a nice long-tube header as well. You might also be able to score one from the same ministock guys.

Are you allowed porting modifications in the head? If so...obviously do it! Unshrouding the valves in the chamber is very important. What about valves? Are you allowed cam swaps? If so, choose wisely. You can run a pretty hairy cam in a stock head and gain a pretty decent amount of power and response. Mill the head to bring up compression. However, if you are able to get flat-top pistons, measure how thick the crown is, then see how thick the stock turbo ones are. I'll bet the flat-top pistons are VERY thick and are heavier because of it. To get around this, figure out how much you can take off the top of the pistons, then mill the block so that much of the pistons sticks out of the hole....then zero deck the pistons. Now you have very light, flat-top pistons, and you can now aim for your compression goal with the chamber size. Remember that with all this milling your cam timing is going to be off. Either an adjustable cam gear, cam keys, and/or possibly even a shorter belt (hint Volvo hint) may be needed. Don't forget to centerline the cam.

Only bore the block as much as is needed to bring it within spec.

The usual oil pump hole porting, and blueprinting would be a good idea, as well as pick-up mods. Don't forget to set the pick-up height. I'd run a crank scraper of some sort. An oil pan baffle is a great idea as well. I'd also run an exhaust evac system to help oil drainage from the head, ring sealing, oil sealing, and windage.

Exotic hardware isn't needed. Good stock stuff will work just fine. Port the water pump housing and use a good size radiator and oil cooler as suggested by others. The Accusump is also a god idea, but if you have the crank scraper, baffled pan, and the evac system, I don't think it's needed.

Good ignition is key. I would not try to use the stock timing curve simply because with the completely different internal set-up and such it won't work well. There are several ways to attack this. I think the simplest way I've seen it done is to lock-out the timing on a regular mechanical distributor and use an MSD system.

I don't know the rules about preparing the engine for this type of event, so there are things I might have put out there that aren't legal. There are also some things I left out just because I don't know the rules and what you are, and aren't allowed to do.

Also, what is the set budget? That will also determine a lot.

Remember, MOST of your power is made at the cylinder head, but there are a LOT of other places to gain not only power, but response and reliability.

[RoadWarrior222]

Personally, I'd be inclined to get a good 2.5 TBI motor, do the durability mods, cooling, oilpan baffles, (gas tank baffles/V6 or turbo tank) then put a cheap T1 setup on it. 150hp.... 'coz honestly, I think you'd spend $150-200 in machining and bolt ons to get 130HP N/A and you could prolly get a turbo on it for that.... just don't allow any provision for turning up the boost when you get the fever in the middle of the race

[shackwrrr]

Personally, I'd be inclined to get a good 2.5 TBI motor, do the durability mods, cooling, oilpan baffles, (gas tank baffles/V6 or turbo tank) then put a cheap T1 setup on it. 150hp.... 'coz honestly, I think you'd spend $150-200 in machining and bolt ons to get 130HP N/A and you could prolly get a turbo on it for that.... just don't allow any provision for turning up the boost when you get the fever in the middle of the race

The lemons and chump car races are more about endurance than anything. I don't think a Turbo'd TBI would hold up in the long run. Neon engines even have a hard time holding up in these races (oiling issues). I think oiling mods are #1. The fire extinguisher oil accumulator is an awesome bang for the buck upgrade with fittings being the only investment. Just mount it upside down vertically the put an elbow on it and hook it up to the galley. Air gets trapped above the oil and it holds pressure. When you starve the pickup the pressurized oil gets pushed back in.

[RoadWarrior222]

I'd still do it. You'd get just as much durability issues with getting the N/A output up there anyway... will make about the same amount of heat to get rid of.

But... what about slapping a neon head on a 2.5? N/A The flow is there already...

---------- Post added at 01:45 PM ---------- Previous post was at 01:43 PM ----------

BTW, heats an easier problem to deal with than in a DD, since we'd assume you wouldn't be shy about attacking the hood with a holesaw or otherwise making ghetto vents etc...

[OmniLuvr]

this is an extreme budget race

[RoadWarrior222]

Fine... make babbit moulds from scrap palette wood and recast the bearings from scrap bearings. Build up crank and any damaged rods with discarded wire coat hangers and a buzz box. Resize with a jury rigged sapling sprung treadle lathe. Steal an airbox off a truck. Cut out oil pan baffles from the back of the hood, weld them in with coathangers. Crush the FPR to increase fuel pressure. Ghetto extrude hone port the manifolds by twisting 100s of strips of 60 grit sandpaper into strong twine, until you've got something like a long bottle brush and yank it repeatedly through each hole. Back cut the valves with a drill and a file. Use dollar store grinding stones on a drill to deshroud the valves. Round out the valve seat cuts (not the face cut) with the dollar store grindstones or hand filing.

[Vigo]

One thing i have heard about for getting high-compression pistons for cheap is to put turbo 2.2 pistons in a 2.5 common block. They'll stick way out of the deck and you mill them to suit. You could use any 2.2 or any 2.5 tall block piston but i assume the turbo 2.2 piston of any generation has better metallurgy than a non turbo version.

Also, if you run carb 2.2 pistons in a tallblock 2.5 with a 782 head, the combination of the higher compression pistons and smaller head chamber will give you pretty high compression. I think some mild milling could get you to 11:1 on that setup. The 2.5 tall block is the only 2.5 that will accept 2.2 pistons without milling a lot off the top of them. Milling does cost some money so this may be the cheapest high-compression option if you can find the parts.

[Reaper1]

No such thing as a tall deck 2.2. Not from the factory anyway!

[Vigo]

Referring to me? I didnt mean to imply that if it came off that way. Edited my post for possible clarification..

[Reaper1]

Ah...gotcha. The interwebz sucks for interpretation sometimes...

[wallace]

There is another guy running a turbo daytona in the lemons race. He posted his findings on the project section of the "other" web site. It is a good read. The major issues they faced were heat related.

[RoadWarrior222]

.... and something to beware of with older radiators, anything in use 2 or 3 years, is that they can corrode where the fins meet the tubes... this is very hard to spot until the mechanical integrity is made bad enough that the fins fall out. But metal oxides are not good heat conductors, in fact they are often used in ceramic insulators. On a DD, you'd notice this when the rest of the cooling system is in good shape, not scaled up, functioning pump, good stock thermostat, proper cap pressure, not leaking, not blowing HG (Have to mention all this, people get foggy headed about it... "well it's got a leak but that shouldn't mean..." ) EVERYTHING else working as intended, and the temp gauge runs at about 3/8 to a 5/8, in normal driving in mild weather, rather than at about a quarter to 3/8, and will probably kick in the fan at stoplights, without a very long wait.