Questions: Phenos, strut bar, cams, and overbore

[BrokenJohnny]

I'm going to rebuild a ZE over the next year or so as a project engine. I have a couple of questions regarding some parts.

First, I have heard that a front strut bar will not fit if you have phenolic spacers. Between the two, which would realistically be a better choice? (I'm leading towards the strut bar)

Second, does anyone have numbers comparing the stock ZE cams to the coltcams? I don't want to buy them if they're only going to net me a 3 or 4 extra horsepower.

Third, are there any realistic gains to be had with an overbore? Is it remotely worth the cost of machine work and pistons? (numbers?)

I'll give you the basic idea for the project. I plan to build strictly for a naturally aspirated application. However, I do plan on adding a moderate shot of nitrous down the road. I want to rebuild the valvetrain via interprep, aside from the standard catback/headers/flywheel/clutch. I was considering buying a bored throttle body as well.

But regarding the engine it's self, I'm not looking to build a serious "race car". I'm looking for an engine I can rebuild as a project in my dining room over the next year (I live alone in an apartment). Something I can sink some money into, work hard on, and have fun with.

Thanks in advance for any feedback.

[Chefsp0t]

Pheno spacers are shown to give power but I personally wouldn't use them. They cause more trouble than they are worth. If you plan on using spray I would stay away from them. You can always buy a STB that doesn't go over the manifold and have the best of both worlds. King6 has some for sale right now.

Colt cams came in many different grinds. Which grind are you looking at?

Gains with an overbore are going to be minimal (less than 5hp) if you are keeping stock compression pistons.

You sound like you want to do an all motor build. If I was going to start over and do an all motor setup I would get high compression (12:1 or higher) .040 overbore pistons, forged rods, and some race grind cams (over 210 degrees, maybe 235's). Then I would beef up the valvetrain and get a custom ITB (individual throttle body) setup made custom. You would probably see 220-230whp with those mods. Possibly higher.

[BrokenJohnny]

Originally Posted by Chefsp0t

Pheno spacers are shown to give power but I personally wouldn't use them. They cause more trouble than they are worth.

What sort of trouble? I mean, I want my finished product to be as reliable and hassle free as possible.

If you plan on using spray I would stay away from them.

That all depends on how much power I'll be making after the build. I'm not looking to break any records, but I want my car to be fun.

You can always buy a STB that doesn't go over the manifold and have the best of both worlds.

I didn't know anyone made those. Thanks for the info!

Colt cams came in many different grinds. Which grind are you looking at?

Well, here's the thing. I can take apart most of my car and put it back together, but I really don't know much of the finer details regarding things like cam grinds, compression, timing, ect.

I'm not looking to build something that will rev to 8500 and make crazy power all the way up. I want a well rounded cam which will provide a significant improvement over the stock ZE cams. I just don't want my power band between 6500 and 7500. *chuckles*

You sound like you want to do an all motor build.

Yep!

If I was going to start over and do an all motor setup I would get high compression (12:1 or higher) .040 overbore pistons, forged rods, and some race grind cams (over 210 degrees, maybe 235's).

That's sort of where I want to go. But I want to write a specific list of EXACTLY every part I'm going to use before I spend a penny. Basically, I want the engine fully built on paper first.

Regarding your suggestion quoted above, what sort of price should I look for regarding the machine work for a .040 overbore?

Then I would beef up the valvetrain

Springs and retainers for sure. What about the valves themselves?

[/quote]
and get a custom ITB (individual throttle body) setup made custom.[/quote]

As cool as that sounds, I think it might be a little too advanced for me, and it sounds quite expensive.

You would probably see 220-230whp with those mods. Possibly higher.

Really?? I had no idea you could get upwards of 230 at the wheels. Damn! That would be very fun to drive!

But would the transmission really hold up properly with that much extra juice? 3rd gear is a bitch.

[Chefsp0t]

Originally Posted by BrokenJohnny

What sort of trouble? I mean, I want my finished product to be as reliable and hassle free as possible.

Regarding your suggestion quoted above, what sort of price should I look for regarding the machine work for a .040 overbore?

Springs and retainers for sure. What about the valves themselves?

As cool as that sounds, I think it might be a little too advanced for me, and it sounds quite expensive.

Really?? I had no idea you could get upwards of 230 at the wheels. Damn! That would be very fun to drive!

But would the transmission really hold up properly with that much extra juice? 3rd gear is a bitch.

Pheno spacers are not a good idea if you are using spray or boost. They are not made to hold up to the extra pressure in the IM. If I remember correctly, the guys who have used them boosted have blown them on 5psi.

Pricing from a machine shop isn't something I can give you exact numbers for. I was originally quoted about 1/2 what my final bill was after my motor build. A lot of the added cost was machine shop labor. If you just want to go 40 over and you aren't going to modify the heads for larger cams and valves it would be cheaper. I had to have my heads modified and the labor was almost a thousand dollars.

I would upgrade everything while you are in there just so you don't have to do it again. Valves, springs, and retainers. Although this is not really necessary if you are not building a high revving motor.

An ITB setup wouldn't cost that much to make. You'd just need 6 motorcycle TB's and some ingenuity/welding skills.

I've seen a stock ze with full bolt ons and megasquirt make 200whp so I would think that larger cams and higher compression pistons would make another 20-30whp with a good tune. If you do plan on doing all of this definitely get a megasquirt unit. Your stock ecu won't be able to handle all the changes to the motor.

The trans. is a weak spot but if you do go through them quickly you could always make a built one at a later date. That's my plan after I see how fast they break.

[BrokenJohnny]

Originally Posted by Chefsp0t

If you just want to go 40 over and you aren't going to modify the heads for larger cams and valves it would be cheaper. I had to have my heads modified and the labor was almost a thousand dollars.

I don't want to do anything like that. I don't want cams which will require any modification of the head.

Regarding high compression pistons, I'm having trouble finding any on the internet. Will I need to get them custom made?

Also, what more can you tell me about high compression pistons? You said 12:1 or higher. How high can you realistically and reliably go? What are the pro/cons? And is it even necessary to bore to .040 if you're bumping up compression? (You said overbore will hardly add any power.)

Regarding a custom individual throttle, it sounds interesting, but I don't know how to weld, andvI really wouldn't even know the first thing about putting one together, let alone getting it to work properly.

Edit: Two more things.

First, am I going to have to worry about interference at 12:1?

Second, do any speed shops even know how to tune with megasquirt? A lot of people I have talked with don't even know what it is. And I sure as hell don't know the first thing about tuning a car.

[Chefsp0t]

Tuning is tuning. If the shop knows how to tune a greddy emanage or any other system they will be able to tune megasquirt. The shop I bought mine from didn't know what megasquirt was. Then they sold me an EMS Pro which is a megasquirt unit anyway.

I am not sure about the interference thing. You would have to ask a performance shop.

As far as 12:1 compression goes you just need to be able to tune it properly and get high enough octane fuel in it. You'll probably need 92 octane minimum. The pro is that you will have a much more responsive motor. You will have more torque and more power all through the power band. The downside is that it might be a little temperamental. Most heavily modified motors are.

go to Import Performance Parts - Import Performance Engine & Racing Parts to find high compression pistons. Wiseco makes an 11.5:1.

[BrokenJohnny]

If I'm going to go 11.5:1 12:1, is a .040 bore even necessary? I know that a bore will increase compression, but can I go with a standard bore an use high compression pistons? Or will that cause the pistons to be to high and hit the valves/cams?

By the way, thanks for all this information. You seem to really know your stuff. I appreciate it.

[Chefsp0t]

The overbore isn't necessary. That's up to you. I only went 20 over on my build. I don't know about clearance issues with high compression pistons. You'd either have to call the manufacturer or talk to a shop that specializes in motor builds.

[BrokenJohnny]

I'm going to take a wild guess and assume that higher compression means more heat and friction. Will I need to modify the cooling or oiling system?

[Chefsp0t]

I really don't think it works like that.

[BrokenJohnny]

Originally Posted by Chefsp0t

I really don't think it works like that.

I see.

Well, like I said before, I can take apart most of my car and put it back together, but I really know very little about building a high performance engine.

Thank God for forums.

[Chefsp0t]

Yeah, I'm no expert either. I just pass along what I know and help out where I can. I can probably take my whole car apart by now. My interior thread will show that.

Seriously though, talk to a performance shop about this stuff because they will have more answers than I do. I'm rather surprised I am still the only person who has responded to this thread. There are people who know much more than I do.

[BrokenJohnny]

Originally Posted by Chefsp0t

Yeah, I'm no expert either. I just pass along what I know and help out where I can. I can probably take my whole car apart by now. My interior thread will show that.

Seriously though, talk to a performance shop about this stuff because they will have more answers than I do. I'm rather surprised I am still the only person who has responded to this thread. There are people who know much more than I do.

Alright, here's a rundown of what I am thinking about so far:

Engine:
Interprep springs
Interprep retainers
Colt cams (possibly 210. Haven't decided yet.)
Phenolic spacers
Port and polished heads and manifold
Forged rods
12:1 forged Pistons (Possibly 11:1 or 11.5:1)
No overbore
Gapless piston rings
Bored and polished throttle body (either 64 or 65mm.)
Standalone ECU (possibly megasquirt)
Fidanza flywheel
Southbend clutch

Exhaust:
Probe Addiction headers
Probe Addiction high flow cat
2.25" Catback
Borla muffler (possibly a dual muffler setup)

Now, I'm not good with estimating hp numbers, but I'm guessing that a build like this should net me at least 200 hp at the wheels.

Is there anything else I should be considering for this build? (Such as getting my crankshaft lightened and balanced or knife edged, getting the rods polished, air conditioning delete (it doesn't work anyways), maf delete, ect.)

[Chefsp0t]

The list looks good on paper. That's a lot of money there. I agree that a motor with those specs should net you 200whp. That's probably on the low side too.

I'd ditch the borla idea and get a custom mandrel bent setup. Borla would choke your motor up more than a 2.5" setup would. It will be cheaper to go custom too.

Knife edging would be a good idea if you're going to do all the other stuff you mentioned. Every little bit helps.

The AC delete is rather easy. I did it to mine. The maf will be deleted if you get megasquirt anyway.

[Fastest95PGT]

I didn't read the majority of this thread. Like, all but the first post and a couple snippets after that. This being said...

Originally Posted by Chefsp0t

Pheno spacers are not a good idea if you are using spray or boost. They are not made to hold up to the extra pressure in the IM. If I remember correctly, the guys who have used them boosted have blown them on 5psi.

I ran phenos on both spray and boost for about 50k miles with zero issues. I bought them before they came with a paper gasket for each side of them as well.