whyteryce

I can see all the flames coming to me from this post already. I was wondering if anybody has ever installed a turbo on the SOHC motor? I know people are going to say it can't be done and to those I say: if you have enough john dough, anything can be done. I have been reading several good FAQ's on other turbo boards and there is alot of talk about mounting a 'universal' kit on any motor. I also know JG Engine Dynamics does a lot of work on custom setups.
Another question is what kind of HP can be had out of the SOHC motor? What kind of gains would we see if we ported and polished, throttle body, larger VAF, header and exhuast?

Identity_X

with enough money, anything can be done as you said it yourself............, but why not upgrade to a DOHC motor before the turbo ??? ........that shouldn't cost you that much and it has much more potential for power.......

how many miles does your current motor have ?

whyteryce

Current motor has 195,000 on it. I agree that the BPT motor is the way to go....I will prolly use this motor until it is no longer running or I come up with $1000 for the BPT motor...most likely the BPT will come first. I see where CorkSport has the 180HP BPT for $990...quite a bargain if you ask me any...certainly cheaper than trying to put a turbo on a SOHC motor. I can get a standard B series DOHC motor for $695 shipped to my door... for three to four hundred extra I can get a turbo!

Identity_X

there you go.........your motor is pretty old as it is so you might as well get a DOHC motor with less miles than your current motor and just slap on a Turbo and you're set

whyteryce

What all is required for porting? Would anything else need to be strengthened? Does the DX use the same internals(rods, pistons, camshaft(s))?

zenilder

The only thing needed to be strengthened, would be the tranny. That's simple--you drop in a manual gear box from a LX (Gseries box, look at the forum faq). People have said it would be better to have the half shafts from the LX. It is a three-piece system, and is said to eliminate torque steering (lessen it to a degree, actually). I have the 16-valve SOHC, and I really don't notice any torque steer. Then again, the only thing I've done to my engine is advanced it's timing. So, I really don't have enough power to see any torque steer. It's not that hard to change over to the LX drive train. I'll prolly land up doing it when I finish my NA engine.
To get back on track... Jesse already answered your question about internals. They have the same bottom end, with the exception of the pistons, which are dished a bit more, hence a slight drop in compression. The engines found in the DX Pros have different heads (either an eight-valve SOHC, or a 16-valve SOHC). If I'm not mistaken, the 16-valve SOHC and the dual share the same valves. The camshafts are most definitely different from the LXs, as the DXs only have one camshaft.

Porting, well, you take the head to a machine shop (preferably one that works on imports), drop the thing on their counter, and tell them to port the f'er.
You'll prolly pay quite a bit for it, so it would be cheaper to simply buy a used DOHC, or get a BPT. It might be cheaper or the same as buying one of these engines.

Oh. You also have to get a new intake manifold. The manifolds on the DX engines have a two-piece manifold. I don't think they would hold up too well to boost. That can be done by taking the manifold to the same machine shop and have them weld it together. (The LXs have a two-piece design, too, but they have a VICS system incorperated, which would be of no use on a turbo engine.)

I think that about covers your Q's. Good luck on your adventure. :P

zenilder

Yes. A few extra hundred will net you a BPT, but you also have to consider that you need a new clutch to handle the power, a gear box from an LX to handle the power (the DX tranny will break from so much torque from the BPT), and you have to put an IC w/ plumbing in to avoid detonating your engine when it's hot outside.

So, you have a clutch from ACT, prolly about $230 for everything. Then, you have the tranny, which will be just over $300 from any wrecker. You can save some money if you go to a yard and pull it yourself, but you have to wait until a LX with a manual gear box pops up (which usually is not too often). The IC and plumbing, you'll have to talk to Branden on this forum about. I have no clue how much he charges for it, but it's a nice setup and worth it. I also don't know how much an IC setup usually cost, so I can't guesstimate. Branden is turboge on this forum.
You'll also need a LX wiring harness and ecu (as you have a DX), which is required to get 180hp out of the BPT and for it to work properly. I think he has a spare wiring harness and ecu still, too. Although, I would talk to him about it soon. Or, instead of getting the wiring harness and ecu, you can buy a stand alone. Though, since you're a beginner in the engine/mechanics area, this prolly won't work best for you. You are required to know about tuning an engine and programming the EMS. Otherwise, you'll be paying quite a bit of money for someone to tune it for you.
Branden would aslo be the guy to talk about for the stand alone system. He prolly has a configuration for the Haltech system you could use if you buy a Haltech.

Hmm.

zenilder

Depends on what year you have of the DX. The later years(90-92) had the 8.5:1 CR, while the earlier years (93-94) had the 8.8:1 CR.

zenilder

It may have only been the '94 that had the 9:1 CR pistons. I have no other way of knowing aside from word from others that have dismanteled BPs. I've only heard mention of 8.5 a couple times, and I would say they are only found in the eight-valve BPs as they have two larger diameter valves and need more clearance. I don't see many eight-valve BPs around. As for the 8.8:1 CR, it is more often stated from those that have rebuilt their engines that the later BPs had these pistons. I searched on this forum, and there are more results for a 8.8:1 search versus 8.9:1. 8.9 comes up twice, once by you, and another time by Jesse, in which case he said he wasn't sure on the compression.

*shrug*

Either way. I'm not going to get in a debate on this. If it's 8.9, so be it. I was mistaken. The only way to find out for sure is to take a BP that came fresh off the line in 1990 and take a compression tester to it and then do the math to figure out the CR. Then, do the same to one from 1994.

How much did you pay for your factory shop manual?

whyteryce

Probably a cost issue on the brochures or some corporate BS...This is really a good discussion...I am glad my newbie *** decided to ask. Makes me wonder how much car manufacturers really hide from the general public. I did IT support for a company that designed semi trucks and the engineers where always changing things that never made it out to the public...they were in effect 'seamless' transitions...little things here and there.
I believe that I am going to plan on getting a BPT in the near future...perhaps once that is done I will mess arounnd with the turbo on SOHC motor...it sounds like a fun project.

protejay

Does the DOHC have it as well?? It would make sense that it would....
How can you tell the steel oil pan from the aluminum one by just looking at it??
Also; strange that Randy doesn't make any mention of this on his 'engine' guide....

And Wil ( notice i got your name right ) yep the 94's would make a little more power; Jesse also mentioned that they have a 'better' exhaust manifold - which i wasn't aware of.

protejay

Man....what more could we ask for out of a 'economy' car 4cyl engine??!
Forged internals, MBSP, piston oil squirters - no wonder the BP is sooo SOLID!!

hmmmm just had a thought...might this make an UR underdrive pulley a little safer?

Elchulo

OHHHHHHHHHHHHHH pictures!!!!!!

94dxpro

"Underdrive pulleys are fine on NA BPs"

PseudoRealityX i thought you said pulleys weren't a good idea on bp engines because they mess up the oil pump???

zenilder

There is no way for underdrive pulleys to affect the oil pump. The oil pump is not run off the main pulley. The oil pump runs directly off the crank.