Suggestions for Zetec engine mods

[FE07]

Well- appears my head gasket is blown and has probably been slowly leaking for at least a year or so. Symptoms- on track- a combination of heat and revs (more revs) lead to pressurizing of the coolant overflow tank and spitting of coolant.

On street- couldn't figure out why I seemingly always had to tighten the hoses clamps on my silicone hoses. Car always had a slight 'eau de antifreeze' after a couple of minutes of driving!

 

Car is going up to George Alderman on Tuesday and he certainly knows his way around Caterhams. Just thought I'd ask the group for any suggestions to increase performance of the engine when the head comes off and any experience with mods they might have done in the past.

 

Thanks,

 

Jim

[slomove]

What is your starting point? Just a stock Zetec with stock ECU and TB ? What is your budget? And how many miles on the engine?

[James A]

In general $ = hp so what is your budget, how will the car be driven, street, autocross, track, what? There are a couple of books out there with good info here is one: http://bit.ly/2vuw2v0 Lots of suggestion in this book, I think his dyno numbers are a little speculative but a lot of good info. In general you will be looking at all of the usual suspects: compression, cam duration & lift, porting, etc.

[FE07]

It's a Zetec with variable valve timing on intake and a modified intake cam. Engine has about 13K miles. Had a modified Ford ECU but had idle issues and a weird/sporadic engine miss (fuel?/ignition?) which cleared up with a stock ECU, so currently running a stock ECU. Have dealt with Turbo Tom in past with modifying the ECU tune so guess could go back to that as well. Car is both for street and track. Will never see more than 2K miles/yr with me. Believe the throttle body is stock. Has nice headers.

 

Budget- guess it depends on what $ get me for HP. Don't need to tell you guys that 10 HP can make a big difference in these cars. Willing to spend money on head work while apart. Guess just wondering what's the best bang for the buck while it's apart.

 

Thanks guys,

 

Jim

[slomove]

It's a Zetec with variable valve timing on intake and a modified intake cam.

 

Somebody correct me but the normal ZX3 has no VCT. The ZX2 (quite rare) had VCT on the exhaust side. But if your engine has intake VCT it sounds like a Focus SVT type engine. If that is true, compression is already increased, valves are bigger and the cams are hotter than a standard Zetec. You can surely get even more aggressive than that but might not be 91 octane compatible anymore. Otherwise, maybe ITB setup, aftermarket ECU? Removal of the VCT and adjustable cam sprockets might make that easier but I found on my engine the removal kits are not easy to get anymore or don't work properly.

 

But it might be an idea to take a turn on the dyno and get a baseline where you are now. If you see already 170-180 hp at the rear wheels around 7000 rpm that is about as good as it gets with a streetable 2 liter Zetec on 91 gas (without turbo or high rpm modifications). I guess that is equivalent to about 210-220 hp at the crank.

Edited August 13, 2017 by slomove

[FE07]

Almost positive it's a ZX2. Apparently from a Contour not a Focus. Trying to maintain fuel injxn as opposed to ITB's.

 

Thanks for the suggestions so far. I'll talk to George and see what he suggests.

 

Jim

[Kitcat]

I am pretty dense but I didn't think ITB's were incompatible with fuel injection. In fact I thot they enhanced it? MichaelD had his Zetec tweaked by Quicksilver in Frederick MD, I think. He makes 218 hp vs. my SVT's lowly 160. I dont think George A. builds engines but, I may be wrong about that (too:)).

[rzempel]

I would ditch the head you have. That variable cam thing you have is just a fixed advance at a certain RPM for smog, not performance. Useless complexity.

 

Start with a skimmed head with bigger valves and porting. Add stage two cams and adjustable pulleys. Also throw away the stock ECU and replace it with a fully programmable one. That should get you at least 150 hp at the wheels.

 

Just my opinion,

Randall

[Automoda]

I just got my ZX3 dyno tuned last week. The guy that did it was a true expert, knew the Megasquirt II well, and was amused by the open loop type of tuning (No vacuum-- Jenvey TBs with 2 inch intake manifold makes generating a smooth vacuum impossible even with a canister). He said that most of the real tuning would be accell enrichment tweaks once the base map was complete.

 

Here's what he said: Max HP 160 at the wheels and decent torque. But he was at a loss for some of the engine's quirks. He'd never seen an engine less sensitive to adjustments in timing, especially at the high end. There was nearly no difference between 25 and 35 degrees at the top cell. He says it acts like a low compression engine that way and that I should think about changes in the head. Looking at the different runs, they were all rather close. There's a strange horizon in the VE table where, regardless of RPM, there's a fast transition between low and high numbers. He thinks my 45 TBs are over-sized for the flow the head is getting and its maxing out early. I'm running stock internals, so it makes sense. Interestingly he got it so it doesn't choke-off at 5800 like it used to and is a surprisingly straight path up to the limiter at 6500rpm. It was tuned at 4000 feet on mid-grade gas.

 

So I'm thinking perhaps its time for some improvements. What suggestions would you guys have? Are the big Ford heads even available anymore? Can these heads be affordably improved?--- Shaving, porting, are bigger valves available, etc? My friend has a set of stage II cams I could get for a good price. My home is at 6,000 feet, so I could use some more air regardless. I'm more of a body guy than an engine guru so like the original poster, FE07, I could use some good advice on this subject.

[James A]

OK, if it is a Contour head it has variable exhaust valve timing, and as already mentioned that is for smog only. Talk with Tom, you can put a VCT eliminator on that mess. Tom can give you great suggestions on how to improve hp and he can tune the stock ECU to match how you modify the engine. Oh, and Contour compression is low, something like 9.3:1, I'm not positive but it is low. With the VCT eliminator the Contour head can be modified to work as well as the Focus head.

[Alfonse]

Turbo Tom did work on the head on my Zetec for a previous owner. It has quite a few mods. It is lots of fun to drive though and never seems to run out of breath until the rev limit is hit.

 

It has:

 

• Crower Stage 3 cams
  
• Emerald ECU
  
• 45mm Raceline Injector Throttle Bodies
  
• ARP Head, Crank & Rod bolts
  
• Under Drive Pulley System
  
• Adjustable cams
  
• Crankscrapers
  
• High rpm oil pump with hardened gears
  

 

According to the previous owner, he had a base line dyno in Ohio to see what it was doing, 113 REWHIP at around 5600 RPM. After Tom did the heads and cams & tune, it made 185 REWHIP. About a year or so latter, after he spent about 2 days fine tuning the cams, he took it back to the same dyno here and it did 203 REWHIP he thinks at 7,800 RPM. All of this was on pump gas, since it was a road car.

 

I've verified most of those parts are in the car and that it is a blast to drive. FWIW.

[FE07]

Thanks for the advice guys. Taking it up tomorrow and I'll see what they have to say. Like the idea of the VCT eliminator and more adjustablity of cam timing.

 

Have worked a little with Tom in the past and I'll give him a call. Keep the ideas coming if any more.

 

Jim

[1turbofocus]

Go to a Focus head and loose the VCT head

 

Have the Focus head rebuilt , stock valve job , surface the head .025-.045

 

Ford Racing valve springs

 

Comp stg 2 or 3 cams

 

ARP head studs

 

Ford stock head gasket

 

I can do you a custom tune file to make it all work

 

Tom

[1turbofocus]

A lot about your new tune you posted concerns me greatly , you dont have a working knock sensor any more so him getting aggressive with the timing is a hugh mistake , he obviously had no clue what he was doing with a Zetec engine

 

160HP is low with ITB and a stock Zetec , something is holding you back , Intake , Exh Tune etc

 

I would go for compression surface the head .025-.045 , a set of stg2 or 3 comp cams, adj cam gears , doing a bunch of head porting and bigger valves isnt worth the cost vs the gains

ARP head studs and stock Ford HG

 

Tom

[Automoda]

A lot about your new tune you posted concerns me greatly , you dont have a working knock sensor any more so him getting aggressive with the timing is a hugh mistake , he obviously had no clue what he was doing with a Zetec engine

 

160HP is low with ITB and a stock Zetec , something is holding you back , Intake , Exh Tune etc

 

Tom

 

Don't worry-- He didn't leave the timing aggressive. He was confused by the way it was behaving and was just fiddling to see if he could pin it down. He dialed it back down to a safe level. He actually agreed with you 100% and said he felt like something was holding it back but he couldn't think of what that would be. I kinda feel like it vibrates more than it used to before I changed out the computer and EDIS4 and fuel pressure regulator and coils. I've checked the mounts and other bolts alternator mounts and they're good. 160hp is pretty boring but remember it was at 4000 feet and I live at 6000 feet. Nothing can be wrong with the intake... its 2 inches long. I sprayed starting fluid around it to see if the gaskets had leaks and it seemed fine. Stock Birkin exhaust is pretty free flowing. I cant imagine that something is plugging up the muffler, but it is something I'll be checking on.

 

Thanks for the advice on improvements. I'm kinda surprised. I thought porting was the 'thing to do'. If its not worth it then I'll skip it. What sucks is I had a chance to get stage 2 cams from a friend and passed on it.

[1turbofocus]

Don't worry-- He didn't leave the timing aggressive. He was confused by the way it was behaving and was just fiddling to see if he could pin it down. He dialed it back down to a safe level. He actually agreed with you 100% and said he felt like something was holding it back but he couldn't think of what that would be. I kinda feel like it vibrates more than it used to before I changed out the computer and EDIS4 and fuel pressure regulator and coils. I've checked the mounts and other bolts alternator mounts and they're good. 160hp is pretty boring but remember it was at 4000 feet and I live at 6000 feet. Nothing can be wrong with the intake... its 2 inches long. I sprayed starting fluid around it to see if the gaskets had leaks and it seemed fine. Stock Birkin exhaust is pretty free flowing. I cant imagine that something is plugging up the muffler, but it is something I'll be checking on.

 

Thanks for the advice on improvements. I'm kinda surprised. I thought porting was the 'thing to do'. If its not worth it then I'll skip it. What sucks is I had a chance to get stage 2 cams from a friend and passed on it.

 

Whats your WOT Air Fuel after 3500 ? Whats you timing look like after 2500 ?

 

Pictures of under the bonnet ?

 

Porting doesnt do much at all , the Ford Racing head was the best one out there and they stopped making it , even then it was hard to get the HP vs the cost , Cams would be my next move and adj cam gears

 

Tom