I race mini-stocks at the local circle track. For next year I retired my 86 Plymouth Turismo 2.2 and am building up a 87 CRX with a 1.5.

This is my first Honda, (but they are cleaning up at the track) so I may be asking some dumb questions.

Is the 1.5 engine a "free wheelin" motor? If the timing belt breaks, am I gonna have a bunch of bent valves? Or is there enough clearance like there was in my 2.2?
Is it worth my while to put a thinner head gasket in?
Anybody know anything about re-jetting carbs? How big a jet should I go to?

It is a 1/3 mile banked paved oval I race on. The car won't get past 3rd gear, so I'm looking for low end grunt instead of top speed.
Any help would be appreciated, but don't start screaming "engine swap". It has to be stock engine for the car. And dual cams, and 16 valve engines aren't allowed either.
This years champion ran the same car, so I know this car will work for this class. But any help tweaking this car would be appreciated.

 

do some head work port polish mill up the compression. new pully, lightened flywheel clutch, if the timing belt breaks your fine, however if head is milled you be come less fine as far as carb stuff goes couldnt tell ya. i only know abou efi.


[Modified by TorteX, 7:25 PM 12/14/2002]

 

i don't think any honda OHC motor is free spinning.. you will always smash valves


but they don't break often like the 2.2

 

obd0 motors dont have engine damage like obd1 and up do. snap a belt it'll fire all ******* stupid and die. fix belt sart up no problems. easy to find out. pull an obd0 head off and look at how far the valves *dont* move. they never go past the base of the combustion chamber unless the head is milled. d16a1 tegs have dished pistons but piston to deck clearance is such that you cant hit a valve. dx motors have a very small piston to deck clearence but a large chamber.

moral of the story, you cant bend a valve unless you have head work on an obd0 d series and previouse. i do not know about obd0 B series motors.



[Modified by TorteX, 7:41 PM 12/14/2002]

 

if you can do stuff to the tranny i would get some short gears from an si or something that'll put the low end up higher

 

My timing belt snapped and you know what happened
i bent 6 valves!
this was on a d15b2 in my 89 dx hatch
So most likely you will bend some valves
only because of luck do sometimes, you don't bend valves

 

The timing belt on my car broke before I got it. They said it bent valves but it didn't. Reason I got it for 700 bux....

 

I snapped an OBD0 B16a timing belt with PCT (CTR) pistons. Did not bend a single valve. The head has not been milled. I put a new one on and it fired right up no loss in performance. I don't have any experience with thoes early honda engines.

 

k this its my opinion
Honda engines lack of low end power (torque)....
get a Si tranny and rebuild it , they are the best for very low gears....
if u wanna swap the engine go with a B18.. if not then a ZC or SOHC VTEC they will bea cheap for that kinda setup u want it for..
if u wanna keep ur stock engine, then i tell u to get rid of the DPFI and get some dual weber carburators or something....seen it before done in the Honda tunning a few months back.....
i guess that the best options u can do so far...

 

he said he can't swap, and this is a first gen non Si... he already has carburators

and as far as the timming belt issue goes, honda engines are listed in the manuals as "interferance" engines, which means that there is a <U>chance</U> of bending valves, that doesn't mean it's going to happen every time. It doesn't happen very often, but it is possible. I'd get a new one on there just to be safe.

And a definate on getting a lower gear ratio in there! these smaller honda engines won't make the power in the low end, try to keep it above 3500-4000 while racing. A friend of mine races in the local "dash for trash" series, a full contact oval race that doesn't allow any mods at all to the car (except a roll cage, but even that's optional) There's a guy there that runs an Integra, and what he does to win the race is just stick it in second and hold it to the floor, bouncing off of the rev limiter. It's really hard on the car, but it works for him.


[Modified by thumpu77, 9:15 AM 12/15/2002]

 

I figured that is why I was getting beat at the track. The Hondas that were passing me had the engines screaming. My poor little Plymouth couldn't take the high RPMs. I learned this the hard way, but the 2.2 makes a spectacular plume of smoke.
Unfortunately I don't have a rev limiter on the car, but it would be nice. One racer leaves his car in second gear and runs it at 7000 rpm. Myself I'd too worried about pushing it a little farther and... boom.
So I'm hoping in 3rd gear I can get the RPMs around 6000. Guess I need to do some calculating before I figure out what gears to put in the tranny.
Or where do you guys think the best RPM to run at is?

 

Can you give us the motor preparation rules for the class? I think we could be much more helpful if we knew what your limits were...ie., after market - pistons, cams, rods, valves, springs, carbs, intake manifolds, pump gas, race gas, compression limits, etc.

Kirk

 

Im pretty sure he said no mods at all, and no fuel injection

 

The rules say the motor has to be completely stock. Re-jetting the carb is a bit of a gray area, but I did it on my other car. So anything I do, has to at least look stock. So changing the gears in the tranny isn't noticable. I thinner head gasket is something else I was considering to raise compresion.
I could probably get away with swapping a different head onto the engine, as long as it was a Honda head. Any suggestions?
BTW, what kind of engine do I have? I read all you guys spouting numbers refering to your engines, but I don't know what mine is. It is an 87 carburated 1.5, that's all I know.

So anything I do has to be pretty minor. No fancy cams, pistons etc. But I will be replacing the timing belt (just to be safe), and the valve springs. Probably some that are heavier than the originals, as long as they look stock.

 

Find yourself a PE3 Candian head (I am assuming that you are running a PE7 American head) - it has a different combustion chamber design complete with squish zones and more compression. It looks exactly the same as the American head until you turn it over, same valves, etc. But, if it is a cheater head - you would not want to do that would you?

I run the same motor as you do...the stock rod bolts are fine to about 7500 - it is valve floats that you need to worry about - shimming the stock springs should be sufficient for your needs.

I have to assume that they will allow you to rebuild a motor to "stock" specifications, won't they?

Kirk

 

your motor is a D15A2...
76hp @ 6000
84ft lb @ 3500
9.2:1 CR

just to be sure, look at the tag in front of the battery...if its still there...this will tell you the engine code.

i have an 87 crx dx... its my winter beater though - its got the dodge plum of smoke!


[Modified by fastcrxsi90, 6:03 PM 12/16/2002]

 

this might help too

http://www.geocities.com/MotorCity/9905/specs.html

 

I had an 86 Dx. Best un noticable mods would be to deck the head, thinner gasket, Si trans, lighten the stock flywheel, and a new clutch. I had not heard about the canadian head swap, but that would be good too. If possable I would recommend swapping for an Si engine and adding carbs to it (Si's were fuel injected). That would ditch the CVCC/EGR system and will make the engine easier to work on. When ditching the CVCC/EGR you will need an Si exhaust manifold because the Dx will have an extra port. The Si one flows better anyway and porting it could only help.

I have an Si engine/trans/newer clutch (200mi or so) id be willing to sell but shipping would be tough.

-Dustin