zenilder

Hey... Been a while since I last posted.

I am having my mechanic machine my engine for me, but I have a question regarding the crank. The DOHC engine that I paid 150 for from a guy I know on the EGT list landed up being F'd. The block itself was already .5 mil over, and the crank was 10/10, as the mechanic put it. I already bought Miata pistons that are a quarter over, so I can't use that block. The crank was bad, so I couldn't even use that. I landed up pulling the spare SOHC engine I had in storage to take to my mechanic. As it has been found, the SOHC crank is cast... Will I have problems down the line?

I'm not going to build up a purely street NA engine here, so I'm not going to make massive power. Prolly around 200hp with what I'm putting together. Will the cast crank handle this okay?

For those who want to know exactly what I'm putting together:
1. A P&P'd gude DOHC head with "15 hp" (claimed from the guy I spoke with at Gude, but the jerk never gave me a straight answer to whether or not the cams were from him) cams. The head is shaved also.

2. Miata pistons, 10:1

3. Custom built cam gears by the mechanic for timing purposes

4. Injectors flow tested and matched

A few other things here and there, but these are the most important regarding power production.

For now, I'll have to run off a DOHC ecu. I'm not going to race it much or drive it hard in fear that it might run too lean. Have to save up a little to get the Wolf 3D EMS I want from Wolf EMS.
I'll prolly only land up putting on an adjustable fuel regulator and a higher-rated fuel pump.

Any other suggestions are welcome.

Thanks in advance.

zenilder

Hrm. Just came across something which changes my idea about flow testing and matching my injectors, so I may be replacing them after all.

Anyone know good replacements that will fit without problems?


Well, I searched around for a bit and looks like I'll try a set from a 89.5-92 Toyota Supra non turbo at 305cc (light green top) first, and if it still runs a high duty cycle, then I'm going to pop in some from a 91 B2600 truck at 326cc.

I'll keep looking...

Davard

The stock ECU will be the first big limitation on a HP build-up. One member of the EGT list put a lot of money into building up his BP (all of what you mentioned plus 11:1 pistons) and only managed 120 whp. Of course, his $2 autozone water pump alternator belt coming on his first dyno pull probably didn't help things. (His car overheated during the second dyno pull).

You really need to go with an aftermarket ECU to make the most out of your mods.

Oh, and 200hp is hardly a "mild" N/A motor.

snart

There isnt many 200 HP N/A BP's out there... toda maybe?? Anyways... the crank should be fine, but other opinions are always good. As far as I know though, the BP's bottom end wont be a worry.

zenilder

True, I don't know that the cams will help out greatly. The guy said he'll take a look at them, and if I can do better with a regrind of the stock ones, he'll recommend the regrind.

I still have to run the pistons up to him so he can actually start machining everything, which I'll do today around lunch. I'll mention to him the bolts. It was definitely on my list, but I don't have a good tap set on hand so I'll land up asking if he can do it (a little extra money, but worth it IMO).

Well, my goals for the engine are not for massive power. If I don't reach 200hp, then that is cool. I'd be happy with 150 at the wheels.
I just wanted to build a slightly stronger engine than most Pros.

Yes, putting solid lifters from toda was something I was thinking about, but I certainly won't be doing it right now. Cash contraints. I'll prolly put them in sometime next year, or, heck, if I can't stand the HLAs after I have the engine built, I'll splurge for a set.

Stiffer springs are something I'll have to research into. I remember reading somewhere that someone found double springs for the 1.6, but I do not know if they are applicable for the 1.8.
Jesse, know of anything off-hand?

The intake and exhaust will come eventually when I have time and money. I think the stock DOHC VICS mani will do okay for now. I already have a POS Corksport header that I bought off GroHarlem, so I'm sure I'll get a bit more power out of that than with the stock exhaust mani. On the intake side, the only thing I'm doing for it now will be to buy a PRM intake system with a RX-7 MAF. I'm not sure if I want to do a CAI as of yet, as it's been raining here in socal, and I would fear for my engine if I were to put a CAI in. I might adapt something so I can switch it out easily when it rains and back again when it's sunny.

True, 10:1 is low, but I didn't have the money to have custom pistons made to have 11:1 or higher. Plus, I don't want to build an interference motor, but the engine may land up being one as it is.

Yeah, I know my power is within the use of a stand-alone. The system I want is 1500 so it's going to be a bit till I purchase it. I'm already sold on a Wolf 3D from reading about it and a buddie from down under recommending it, as he uses one for his Datto. The system also has a nice secruity feature.

Hrm. We'll see. I really know I need the EMS, but it's kind of hard right now.

Thanks for all the input. Please continue to comment if ya like!

turboge

Donnie still has that motor available for sale I believe. If I was going to build a real racer i'd stick it in with the haltech and tune the **** out of it on 116 octane.

mazdaspeedwest

wow, the ECU is a bottleneck, as i came close that with mere bolt ons. (115whp) That torque curve doesn't look as nice as mine either

and Braden hit 120whp with just a Haltech and 3" exhaust....mmmmm

zenilder

Thanks for all the input.

I talked the mechanic today and discussed my options regarding the crank. He could do a couple of things: use the cast or build up the bad crank. So I told him go ahead and weld up/grind the throw that was bad on the forged crank. He's going to do some head work that will help (minor things, which can help air flow). He also threw the idea of dropping in some solid lifters with shims from a VW if the measurements are okay, and depending on that, he'll either regrind the cams for solid lifters or not. Either way, he's going to look over the cams and see what the best option is. If no go on the solid lifters, it'll either be the cams that came along with the gude head I bought, or regrind. Otherwise, I'll have to pop for, which I don't want to do considering the price for their set.

The gude head I bought from GroHarlem had already been milled, but he said he'll go back and measure the clearances to see if he can mill it a bit more.

As for fuel... Well, we talked about swapping in other injectors. I was thinking about putting a set from the list a mentioned, buying a high-rate fuel pump, and an adjustable pressure regulator (but I'm not thinking about building up the pressure so I can -force- more fuel through the injectors. no, I know that's not going to happen).

Let's see...

We decided to put a bit more clearance on the bottom end.

I told him I could bring in a set of the valve springs to be measured. He said this engine most likely won't need stiffer springs for higher rpms (so long as we put in the solid lifters), but he hasn't measured the springs yet. So we'll see. I'll run the springs up to him tomorrow.

I'll prolly check with the California distributor for Wolf EMS to double check the price. I know they recently released a number of new models so I'm hoping the price has dropped on the one I want. I really know the importance of the role a stand alone will play here, but I'm really restricted by money.


The machining he's going to do for me will run about 750 - 850 for all that he's going to do. The pistons and gaskets I already bought ran 800-something. So a 1500 EMS is going to be a bit much right now. Six months down the line, it won't be such a problem. So I'm waiting to see how things work out...

Again, please keep the comments coming.

beachnut

Ok, I thought I'd tag onto this thread since it's already started ...

I'm trying to decide which route to ultimately take my Pro. After reading all the turbo threads here, I'm leaning that way but I was thinking I might do it when my current engine blows up and do a BPT swap. However at 157K, that may take a while (at least I hope) and I'd like to get some speed sooner, so I'm looking at Braden's turbo kit too. I doubt that I'll ever autox or run at the strip, but you never know. Geez I'm a 40 y.o. fossil, yet I refuse to grow up, lol ! I would really like to get ~200hp at the wheels, anything over that is probably overkill for me and the car.

Anyway, I bought some AEM adj cams gears on eBay the other day. Don't know why, guess I got the twitchy bid-finger! I've been thinking about getting some Corksport cams, so I thought I'd get these gears while there was an opportunity. Most everything I've read elsewhere says I should get ~10-15hp gain, but a lot of you guys here like David, Darryl, and Jesse don't necessarily agree, and your points are well taken.

If you can't tell by now, let me just say that I'm not a mechanic or a racer, just mechanically inclined. I've never rebuilt an engine, so I doubt if I could put the cams in myself. My buddy with the '91 DX is shying away from the job; he does rebuild and has a nice TA that he runs at the strip. He said it'd be almost better to pull the engine just to put the cams in - is it really that hard? And if I decided to do something sooner like Braden's turbo bolt-on, would the cams be money wasted? Plus, are they any other mods that would be good to do with an eventual turbo path in mind?

Davard

Actually, nothing could be farther from the truth. While it is true that you'd be better off pulling a V--8, especially in a TA, to do a cam swap, with the Protege, it's only a little harder than pulling off the valve cover and changing the timing belt. Yes, it would be easier to do out of the car (everything is easier to do out of the car, including autocrossing for most people ), but it's not necessary. Everything is right there on top of the motor.

zenilder

Well, I need a bit of advice once again.

I've been thinking about my fuel system problem lately. I was wondering if it would be better to install another set of injectors? Since I am leaning towards a standalone, I'm read this would be an ideal configuration to save idle. if I did, I'm not sure where exactly on the intake mani I would put them, but I thought maybe on the bottom side of the intake runners, opposite of the stock injectors.

Again, just a thought and would like to see what others think.

midnightblue97

I'd just get bigger injectors and install them in the stock location. I think it would be too much of a pain in the *** to wire up a second set of injectors and then plumb the fuel lines.

zenilder

Yes, it would be a PITA, but I willing to do it. Even though I'm only going NA here, I want to have the best idle possible. If the setup worked out well, I could then transfer it to, or duplicate it for, a turbo setup in another car (a project I plan to work on in a couple of years).

Thanks.

zenilder

Yeah. That was one option I was considering, and Braden offered a set to me for $200. I might land up taking them, seeing as they'll work with the stock ECU, it's an option that will let me use the stock ECU for a longer period of time (allowing me more time to save up for the standalone rather than saying, "well, it's not going to work unless I get a standalone" and dump 1500 for one ). I still don't want to get the standalone right now, even though I know it is what I need to make the most power. I would at the least like to do with with the stock ECU somehow, resistor inline with the temp sensor or some other kind of quick mods so that I can run the engine without fear of running too lean, or too rich for that matter. It would give me time to buy the standalone.

While I'm typing this, Jesse, what size exhaust would I benefit the most from? I know about the 2" exhaust being adequate, but with the higher compression and cams, would 2 1/4" be more fitting?

Thanks again.

bpt323

just wondering how you can raise your redline capablilites? and where i can get ahold of stiffer springs and solid lifters along with the GTX injectors? a DOHC 4-2-1 header would be nice too!


any help would be appreciated