5 replies to this topic

[Bars84CRX]

1 owner here, resurrecting my '84 DX.

 

The car runs and drives but it has white exhaust 100% of the time and a bubble in the rad while slight blips of throttle.  That's another reason I parked it years ago.  That and having 5 cars on insurance for 3 drivers.  LOL  (Interesting that I'm heading back to that situation by adding this car back. Oh well I digress.)  As such I need to keep costs to a minimum.

 

Devac'ed with Weber carb, homemade adapter, SS DC Sports exhaust, Si oil pan for fit.  Car originally ran ok but opened up better when I added a hole to the homemade adapter plate to feed the CVCC chamber.  Obviously the CVCC port isn't a rich mixture like the original carb.  I'd like as much flow as I can get w/o too much more expense.

 

I have access to a mill so I've shaved this Si head about .025", just enough to clean it up. It should definitely breath a whole lot better!  Head gasket set in my hands.

 

Main question is intake.  I read in the wiki that I'll need the Si intake...which I don't have.  IIRC my intake which isn't out, being CVCC has an extra hole for feeding the CVCC chamber.  I don't have it out so I can't inspect.  Not sure how well my carbed intake is going to match up until I get into them.  I'd prefer the car not be down long once I pull the head but it is what it is.

 

Question: Obviously, I'd like the head the breath as much as possible.  Would you plug the hole on the intake side?  On the carb side just once?

Buy an Si intake?  If I go with Si intake I would need to make an adapter, not a big problem I guess.  I'm better with the mill than I was back then.

What if I port my head, even grinding out the CVCC path so it all matches?  Won't be able to reach all the way up.

Might depend on how cheap I can get an Si intake, too.  Haven't researched it.  (Not one on ebay that I can tell)

What's your suggestion on what I'll get out of it vs cost/effort?

 

Thanks for you time/experience.

 

 

***** Update.... since there's been 0 responses in 2 days, I guess I'll take pictures and document, report back here. *****

(Also, I remember that I have a motor in a wrecked car w/o the head.  I can get a good look at carb'ed intake there)

Edited by Bars84CRX, 24 December 2014 - 12:30 PM.

[WhereIsMyWrench]

Hi! From what I have read I believe others have plugged the holes on the manifold side where it would meet with the gasket/head. I am in this same boat and thinking about swapping to the SI head.

Here are some older posts that I was able to find that may help you. You may have already seen them though.

http://www.automotiv...ew1_engine.html
http://www.redpepper...showtopic=52644
http://www.redpepper...ock#entry558464
http://www.redpepper...ead#entry558023

Let me know if you have any more questions and I'll answer what I can. I don't have much experience with the SI stuff yet but I have read an awful lot.

- Pat

[Bars84CRX]

Thanks, looks like I need a distributor.. or fab something to fit. I need to check things out closer.

[WhereIsMyWrench]

From what I read, you can use your DX distributor as long as you swap your DX camshaft into the SI head. You would then use the additional housing the DX head has for the mechanical fuel pump and distributor to mount to. So, SI head, DX cam, housing, fuel pump, and dizzy.

 

Apparently the DX camshaft makes the same or better power in the SI head.... no hard evidence on that, just what I read.

I actually plan on doing this to my DX in the near future. Take some pictures and post your progress, it's great for others to learn from.

 

[Bars84CRX]

I have a cheap electric fuel pump w/mechanical block off plate.  Project is still on my mind.  Was hoping the Si cam would give me more umph but if not then no need.  Need to get all the pieces on the table and see what I can come up with. I have plenty of spare DX stuff but only the Si cam.  So far I've only located the intake rocker arms, too.  The exhaust is somewhere, just no time to look for it.  Won't matter if I use the DX cam anyhow.

 

Thanks for the tip!  Weather looks good this w/e so maybe it's time.

[Omega Mugen]

I have a CRX DX with an Si motor, DX intake, and Weber downdraft carb.  It runs great.  I think I had to plug CVCC ports in the manifold with PC Fahrenheit, which is an epoxy putty that tolerates high temperatures.  I use the Si intake manifold gasket and ran the Si cam with Si distributer and ran a carbed Prelude electric fuel pump.  Other than the wiring for the fuel pump, all this was plug and play and pretty easy to do.