Engine Build

[bricud]

I am looking to build a street engine (with a limited budget, of course) and am starting with a engine I found with 40K from japan, and was wondering your opinion or advice on what is a must include and what I can get by with.

I was going to start with the TCU and Stage 2V7 engine and transmission management software. If I went with their mild cam (244 dur intake, 256 dur exhaust), 370CC injectors, and Z32 mass air flow meter, is there anything else you would recomment to help things breath? I hear the stock intake and throttle bodies have enough air flow. How important is the exhaust to mod for better flow. Any other necessary internal engine mods to do with this application? I basically want as much power as I can on the street without compromising idle quality, and by the way, I want a pony too. Anyway, what does your experience say I should consider? Any guesses at crank HP for this mild mod?

Can this engine handle nitrous? I have heard that the rods might be a little weak?? Thanks for your response.

Brian

[SVXRide]

Brian,
Welcome.
Couple of things:

1. Define "limited budget"

2. Do you intend on keeping the engine normally aspirated?

3. Define "idle quality"

4. How do you intend on using your SVX? (1/4 mile, highway cruising, time attack, autoX)

Answers to these will serve as the foundation for further suggestions

-Bill

[bricud]

This an extra vehicle, not an every day driver. I will use it to drive around for fun mainly. Probably take it to a strip to check out the improvements, and maybe do a little bracket racing down the road.

By limited budget, I mean to invest less than 3000 in the project in addition to the cost of the used motor. Tranny might come later, as I know this car comes with highway gears, and I would expect I need a taller final drive ratio for quicker times. I should be able to swing a new tranny in a year or so.

I plan to keep it normally aspirated mainly because I am guessing that to go turbo or supercharged means big bucks, but I don't know for sure. The only supercharger kit I saw was somewhere over the 6K price.

Good idle quality means a slightly higher than stock idle speed for a hotter cam is OK, just not too much. I have had some really high lift cams in V-8's that required a high stall speed converter to make them driveable on the street. I want to avoid this. I don't mind a little lope in the engine. I think this is a good sound.

I had the used engine shipped two days ago, and I plan to make the mods before it goes in.

Brian

[SVXRide]

Brian,

Great!

Couple of things to consider then, in addition to what you've already laid out.

1. Heads definitely benefit from attention, especially on the exhaust side

2. You'll definitely want to get the heads rebuilt along with Cometic (sp?) head gaskets for the re-assembly.

3. Buy the Subaru engine rebuild gasket kit (do a search of the SVX site to get the stock #). It has all the various o-rings, gaskets, etc. you'll need.

4. Find a good machine shop that is familiar with Subaru engines to do your block prep. While there is a good chance your used engine will actually still have a visible cross hatch in all the piston bores, you'll want to get the bores checked for taper (you're going to get new rings anyway, right? -- FYI, as far as I know, you can only get rings for our stock pistons directly from Subaru)

5. Port matching the intake to the TB and the "spacers" (sorry, I know there's a technical name for these pieces, but it's alluding me at the moment...) that the injectors mount in will help.

6. The stock exhaust manifolds are a pretty good design. You will benefit from a more free flowing exhaust behind them. Do a search of the SVX site for multiple examples of what folks have done to date. If you want to try out custom headers, check with TOMSSVX and SVXFiles. They have both fabricated multiple sets to date.

Good luck with this and please post up your progress!

-Bill

[bricud]

Bill,

Thanks for the info. I will begin by looking for a good machine shop. I plan to have them disassemble and check the bores, and have them honed. Of course check crank and rods for wear and have them machined as needed. Balance the lower end in the process. See what else they recommend. Are there any specific weak links in the bottom end? How is the crank and rods for strength? I would like the bottom end to be able to handle 450HP so I can add nitrous without worry later.

I'm guessing I can get a little over 300 crank HP without the nitrous. I guess I will find out. Anyway, I'm learning about this engine, so feel free to give me any input you have.

Knowledge is Power, and hopefully this translates to horse power.

Thanks,

Brian

[lhopp77]

Originally Posted by SVXRide

Brian,


5. Port matching the intake to the TB and the "spacers" (sorry, I know there's a technical name for these pieces, but it's alluding me at the moment...) that the injectors mount in will help.


-Bill

Are you referring to the Outlaw Engineering Phenolic Spacers (thermal spacers)?

Lee

[SVXRide]

Lee,

While the spacers are a nice to have (yeah, I have them on Racer X's engine), I was referring to actually p-n-p'ing the stacks to match the intake manifold and the intake manifold to match the TB.

Brian,

A good deal of precision went into the assembly of the EG33, so I'm not convinced you need to spend the $$ on having the rotating assembly balanced (assuming you're staying with the stock rods and pistons). The stock engine should be able to easily handle a 50 shot without any mods. If you do want to buy a little insurance, get yourself a set of STi rods (check out NASIOC for someone "upgrading" to Pauter or similar rods and offer to take the "puny" stock rods off their hands )

Definitely do a search of the SVX Network on the topic of rod and main bearings. There is a topic of discussion as to the type of bearing and amount of clearance to run.

Assuming your trans is in good shape, there is no reason to believe that you won't be able to see at least 200 Hp at the wheels.

-Bill

[longassname]

Are you definitely rebuilding the bottom end?

[bricud]

How far i can go will come down to the cost. I don't have prices yet for machine work, gasket sets, etc. Depending on where that stuff comes in will determine how much I can afford on the bottom end or if my money would be better spent on the top end.

Next week I will check with some shops on prices to get a better direction. As well as spending some time searching this site. Once I begin to get my prices together, I will post them to see if they seem to be reasonable or if there are better sources for parts, etc.

Based on what Bill said, I will probably stay with the stock rods and pistons for my application, but have the bottom end taken apart, cylinders checked, honed, and new rings installed. Along with new rod and main bearings. More to come....

[longassname]

If you are going to reuse your stock pistons then don't do any machine work on the block.

The only reason to take the short block apart if you are reusing your stock pistons (which may be feasible since it is suposedly a low miles motor) is to upgrade your bearings and increase your oil clearances--which is a very good reason. In that case you want to number your rods with a paint marker so you can put them back on the same pins and get your crank polished not ground. You should also put arrows on them facing forwards/inform the machine shop that they are directional otherwise they will never guess that. You may/probably will find your pins are difficult to reinstall but presumably they will be able to manage it.

If you get into having your crank ground the chances are better that it will come out wrong than right and you won't have the tools to check it to find out.

I would strongly suggest using aluminum bearings.

Sorry i can't say either don't bother taking it apart because it's not worth it nor can I say take it apart because it will be easy. Unfortunately, it's worth it and it's a lot more work and you have to be careful to make sure your machine shop doesn't do more harm than good.



You/the shop must also be very careful with handling/transporting the crank. It's not like a cast crank. It will bend easily if knocked over/around. If it's not in the block or on the stand for polishing it should be in a well fitting crate.

[SVXRide]

Michael,
All good advice! Got a question, as this is the first time I've heard/read that our rods are directional. What is it about them that makes them directional? Does this carry over to the 4 cylinder subie engines also?
Thanks.
-Bill

[longassname]

Good question......

I honestly couldn't tell you but the service manual says they are and they are marked. I'm sure if you or I were to look hard enough long enough we could figure it out but I never have. The oil holes for the pins are probably offset or something. I just follow the directions when I use the stock rods.

Originally Posted by SVXRide

Michael,
All good advice! Got a question, as this is the first time I've heard/read that our rods are directional. What is it about them that makes them directional? Does this carry over to the 4 cylinder subie engines also?
Thanks.
-Bill

[bricud]

LAN,

I've been drinking from the fire hydrant today, trying to absorb what is best for my app. I am leaning toward this. Leaving the bottom end stock. Going with a mainly top end mod. Just want to confirm that the cams listed on your site (244/256) work with stock springs. Any additional mods recommended with these cams besides injectors and Z32 mass air flow meter, and engine/trans control modules?

Is all this available?

Also, I have read of people using larger injectors. bigger than 370CC. Any advantage other than planning for future mods? Or should I stick with the 370CC?

I have also read of the coolant bypass pipe that people have been trying to eliminate the overheating prob on the rear cylinders. Is there a source for this, or someone who can tell me what is involved in making it myself?


I would really like to get my heads ported and polished. Can anyone tell me the stock flow characteristics of these heads and how much of an improvement they are capable of? I see that TomsSVX did them himself. Is it worth it for my app??

Now that TomsSVX no longer makes the custom intake, is there another source or some specs I can use to make them myself??

And finally, the engine I have coming is from japan. Are there any sensors that I need to use from my old block or cautions I should consider before sliding it into my SVX??

Thanks for your help.

Brian

[1986nate]

Originally Posted by bricud

Now that TomsSVX no longer makes the custom intake, is there another source or some specs I can use to make them myself??
Brian

I thought there was someone selling one that they had handmade themselves..

And finally, the engine I have coming is from japan. Are there any sensors that I need to use from my old block or cautions I should consider before sliding it into my SVX?

I believe the foreign markets did not get the EGR system but it is not necessary in the US markets unless you need to go through emissions as I believe the 96 and 97 models (OBDII) will throw the check engine light. I am not 100% on this though.

[longassname]

Yes those cams do work with the stock springs. 370cc injectors are plenty big enough and other injectors can not be used without the software being modified. Everything you mentioned is available now but you may want to act on the camshafts sooner rather than later.

Originally Posted by bricud

LAN,

I've been drinking from the fire hydrant today, trying to absorb what is best for my app. I am leaning toward this. Leaving the bottom end stock. Going with a mainly top end mod. Just want to confirm that the cams listed on your site (244/256) work with stock springs. Any additional mods recommended with these cams besides injectors and Z32 mass air flow meter, and engine/trans control modules?

Is all this available?

Also, I have read of people using larger injectors. bigger than 370CC. Any advantage other than planning for future mods? Or should I stick with the 370CC?

I have also read of the coolant bypass pipe that people have been trying to eliminate the overheating prob on the rear cylinders. Is there a source for this, or someone who can tell me what is involved in making it myself?


I would really like to get my heads ported and polished. Can anyone tell me the stock flow characteristics of these heads and how much of an improvement they are capable of? I see that TomsSVX did them himself. Is it worth it for my app??

Now that TomsSVX no longer makes the custom intake, is there another source or some specs I can use to make them myself??

And finally, the engine I have coming is from japan. Are there any sensors that I need to use from my old block or cautions I should consider before sliding it into my SVX??

Thanks for your help.

Brian