sohc_coupe24

One of my friend just recently bought a used greddy turbo kit for his car. The problem however is that he is currently running on his stock cx motor, and he doesnt' know if the stock cx bottom would put up with the pressure the turbo would exert. Right now he has his vtec head finished and hoping he could slap that on before the turbo. But as i had said, we don't know if the stock block would be strong enough to take on the pressure. Any opinions and suggestions to help alot; don't want to boost the cx block and blow it. Any help is appreciated

ppfalcon

if you keep the boost low and take it easy he should be ok, but i would be building a backup shortblock in the mean time , because just because i say keep the boost low doesn't mean you are going to right?

EnzoSpeed

Oh geez, is this what you're referring to?

D15B8
1.5L 8V SOHC PGM-FI
1493cc 70hp@4500rpm 83tq@3000rpm
92-95 Civic CX

I've never heard of that motor before, and now I know why. I'd swap in a more worth-while engine first. A full z6 swap is only $500 on ebay.

Seriously, don't waste your time with a 70hp motor. Most of the d-series aftermarket backing is for the z6/y8 crowd anyway, so down the road you'll have a hard time finding parts.

jundoc

cx is going to blow ... my friend had dx... which is the same engine i believe.. so he blew engine with 7 psi ... with t25...turbo set up....go z6..instead

EnzoSpeed

Okay, I'm back. Here goes.

The standard 92-95 non-vtec single cam motors all revolved around the same platform - the 1.5L D15B motor. All the DX's and LX's were given a relatively efficient 16v head - these were the D15B7 motors that most people have.

However, the CX's, which I can't even begin to imagine the origin of, were made with fuel efficiency in mind (like the vtec-e's of today). Consequently, they were given a horrible 8v head which suffocates the motor. These atrocities are known as the D15B8. So the CX motor you are referring to is basically the most horrible Honda motor ever produced.

That being said, your plan to swap on a vtec head is a great first step. You will gain immense power by doing that. If you tune it right after the vtec conversion I imagine you will see at least a 30hp increase. If you also open up the intake and exhaust, you will probably gain another 25hp.

Now, as for turboing it, you can definitely do 6psi no problem. 8psi might be pushing it. The problem with the D15 platform is that the rods are very weak. A stock D16 motor has stronger rods and can handle about 220whp. However, the D15 can't handle more than about 170whp. If you want more power than that, you'll need better rods. But I'm not sure if you can find forged 1.5L rods anywhere.

Also, don't worry about blowing the block. The block is the last thing you should worry about. Even the D15 blocks can handle hundreds of whp on a good tune. You first worry should definitely be the rods, followed by the pistons.

Bottom line - if you want a very mild setup (~6psi) then keep the CX motor and do the vtec conversion. However, if you want a fast car, swap in a D16z6 motor and then turbo that.

sohc_coupe24

so basically you guys are saying that it'll be allright unless he guns it alot. And i agree with Enzo...probably the weakest part of his build up would be his rods. Thanks for the input though...i guess we'll see how the f/i will do to the little cx.

Dunc

I smell future carnage.....hope it goes well for you though man.