V1 Ross's extended city, easy entry Goblin- 06 SS/SC, NW Arkansas

[mike_sno]

Could you measure how deep from the top of the block the water path around the cylinder goes down? Then if you compare that to the distance from the top to the bottom of the port where the mechanic pump feeds in the block, that could be an indication that all water which goes in the block must pass the cylinder before going in the head.

 

[Ross]

OK, thanks for keeping an eye on the water path and help to solve the myth. Once you posted the head picture you clearly can see the water path. I assume your current theory is that when the engine is cold you only have flow on the head? I'm still not sure if the #1 just gets the head return. Look where the mechanical water pump feeds into the block.
Why can't the water go in that port, around the cylinder, in the head and then either out port 1 or port 3 at the top of the head?
I guess it also doesn't really matter as long as we have sufficient flow in all channels.

You are correct. Water will enter #2, go thru the block, up to the head, where it will leave on port 1 or 3, as long as those are lower water pressure.
- On the stock water pump setup, port #1, the red pipe, orange pipe, purple pipe, is on the low pressure side. High pressure is port #2. Port #3 would be about 3/4 pressure. So water could leave on both port 1 and 3.
- If we remove the stock thermostat, and add a new EWP pump at the radiator, then the water pressure on the driver's side hose is high pressure, and the passenger side hose is low pressure. In this scenario, the high pressure side is the blue pipe, orange pipe, the red pipe, port #1, purple pipe and port #2. The low pressure is port #3. So water would leave only on port 3.
- If we connect port #1 & the red pipe to the hose on port #3, then port #1 would become low pressure. So water could leave on both port 1 and 3.

Those bolts are single use. When I did my head I used this unbolt and rebolt pattern. Worked flawless. I was scared when torqued the head bolts. They scream

Regarding the one cylinder which might run rich or lean, would be nice if we had an o2 sensor at each cylinder. I read that usually the cylinder at the end of the fuel rail runs lean, due to less fuel pressure. An issue to be avoided with the boost reference fuel pressure system installed behind the fuel rail.

Cylinder Head Replacement — 2007 Chevrolet Cobalt L4-2.0L SC Service Manual | Operation CHARM

Detailed repair manual for the 2007 Chevrolet Cobalt L4-2.0L SC.

charm.li

Oh man, now I need to learn how to install a boost reference fuel pressure system.
So fuel pump, fuel rail with injectors, then boost reference fuel pressure regulator should be avoided.
But fuel pump, boost reference fuel pressure regulator then fuel rail with injectors, is good?

 

[ah.b.normal]

So port #1 does just get coolant from the head. The path takes it to the circled blue port. All the blue passages in the block are coolant, while the orange ports are oil passages.
View attachment 50867 View attachment 50868

I decided to undo the head bolts by starting at the outside bolts, then circling inward. When I got to the last head bolt (the one the flex bar is on) it didn't want to undo. I wish I owned a 15mm impact socket... as I broke 3 of my 15mm sockets. Since I was down to my last 15mm, I decided to torque the 5 head bolts near it, then it finally broke loose. I probably way overstretched that last bolt... hopefully not the head too. I have new ZZP Ecotec Head Stud Kit, ZZ-ECT-HSK, so I am not needing the old head bolts.
View attachment 50869

A visual inspection of the cylinder bores shows no signs of vertical scratches, and no wear lip at the top. Pretty good for an engine with 200K on the odometer. I see cylinder #2 has exhaust valves that are a little darker than the other valves. It may have been running a bit rich in that cylinder? Or maybe that injector isn't misting fuel very well.

Those 12 point sockets were never made for head bolt removal and well desperate time call for desperate measures and all, but I've broken my share as well.
My reminder: Have more 15mm 6 point sockets on hand for head/bottom end removal. High quality hardened sockets are sometimes thin walled enough to fit those tight spots.

 

[mike_sno]

Oh man, now I need to learn how to install a boost reference fuel pressure system.
So fuel pump, fuel rail with injectors, then boost reference fuel pressure regulator should be avoided.
But fuel pump, boost reference fuel pressure regulator then fuel rail with injectors, is good?

No, you are all good. Fuel Pump, fuel rail with injectors, then brfpr is ok! Boost reference fuel pressure regulartor behind the fuel raul. That's what I meant. Sorry if that wasn't clear.

 

[Ross]

No, you are all good. Fuel Pump, fuel rail with injectors, then brfpr is ok! Boost reference fuel pressure regulartor behind the fuel raul. That's what I meant. Sorry if that wasn't clear.

Still not clear to me. Your first line (Blue) just put the brfpr after the fuel rail. But your previous post (Green) says to avoid putting it behind.
Are you talking about it's physical location in the car? What is your point?

OK, thanks for keeping an eye ...
An issue to be avoided with the boost reference fuel pressure system installed behind the fuel rail.

Words are ambiguous... pictures are better.

 

[Rauq]

Everything I've read says the best place for the fuel pressure regulator is after the rail. Here's a diagram of my setup, only thing not outlined is the few quick connect fittings threaded for the adapters. I don't have a photo at the moment.

 

[mike_sno]

Still not clear to me. Your first line (Blue) just put the brfpr after the fuel rail. But your previous post (Green) says to avoid putting it behind.
Are you talking about it's physical location in the car? What is your point?

Words are ambiguous... pictures are better.

What I meant is the problem with the cylinder at the end of the fuel rail running lean is a problem which can be avoided by putting a brfps at the end of the fuel rail.

 

[Ross]

i didn't like that the spark plugs were aimed different directions, so I bought:
Allstar Performance 96505 Spark Plug Index Shims 14mm

I was going to aim the spark plug strap at the exhaust valves, so that the intake has an open spark gap, but my search engine says:

When shimming spark plugs to orient them, the goal is typically to position the ground strap towards the intake valve to achieve the most efficient burn. However, opinions vary on whether this orientation significantly impacts performance. Some suggest that the electrode gap should face the intake valve, while others argue that it does not matter much due to the nature of combustion. Race teams often use specific techniques like indexing to ensure optimal orientation, but the effectiveness of these methods is debated.

 

[Rttoys]

Dang. Indexing plugs? I haven’t heard of that in a long time. When you smoke a brisket, do you smoke it fat side up or fat side down? Honestly, I’m a believer in indexing plugs, but I haven’t done it in a long time.

don’t forget to j gap while you are at it.

 

[Ross]

I have never smoked a brisket... and yes, a little OCD here with spark plugs. The goblin is my play vehicle, and I have never built an engine this much before. Re-engineering a lot.

I'm not planning on filing or shaping the j strap on the spark plug. I figure there are a lot of spark plugs available that already have engineering behind them.

 

[Rttoys]

When I worked at the motorcycle shop 30 years ago, it was always plug towards intake valve(s). And J gap on the “performance” bikes when asked. Dang that was a long time ago.

 

[LLBenJ]

Dang. Indexing plugs? I haven’t heard of that in a long time. When you smoke a brisket, do you smoke it fat side up or fat side down? Honestly, I’m a believer in indexing plugs, but I haven’t done it in a long time.

don’t forget to j gap while you are at it.

Smoke that brisket fat side up. As the fat breaks down it has a self basting effect. Some say it's not needed but every time I've done one they've turned out great!

 

[Ross]

Has anybody done their own valve job? Or do you know where I can rent machinist tools from?
I usually use a machine shop, but am considering buying the tools to do it myself.
It requires a 6mm ream, 6mm Tapered Pilot, Valve Seat Cutters: 31° & 46° & 60°

Sometimes I shoot myself in the foot.
I'm trying to remove a cam shaft, and this allen head bolt is being stubborn. I heated the area with a propane torch, and kept working it, but it stripped. I tried stretching it to a torx head, but it is nice and round now. So off to the welder trick. I filled in the allen head with weld wire, built it up a bit,

then welded the nut on. That worked, the stubborn allen head came out. It was a short M12 set screw,.. here I thought I was struggling with a long M8 socket head.

I was thinking I won the battle... but no. That allen head wasn't needed to be removed, as the casting actually splits in half. Doh! Should have read the directions.

Measured the threads, and I bought a new allen head set screw M12x1.5-16mm long. That set screw was a plug for the oil galley that supplies oil pressure to the hydraulic lifters.

Well, the cams came out, as well as the rollers, hydraulic lifters, some retainers, valve keeper, springs, seals and 2 valves.

The old intake valve stem is 5.953mm, and the exhaust is 5.937mm. The new intake valve stem is 5.954mm, the exhaust is 5.947mm. Why more wear on the exhaust? The recommended oil clearance is 2 thou on intake, and 3 thou on exhaust, the difference in size is to allow the exhaust valve more expansion room, as it runs hotter.

 

[Markm]

As much as I do myself I’d say, let the machine shop do what you need done. I’ve done many valves and used a drill and vacuum hose to lap them in but buying a valve grinder would (for me) be an unnecessary expense

 

[Ross]

It is about the same cost to hire a machine shop as it is to buy the tools. Trusting someone else to do the job is hard, but you are right, it would be way easier.

 

[Markm]

I always double check the machine shop and clean everything before assembling my engine just to make sure they did everything I paid for and it’s completed correctly

 

[Esstover]

My wife & I went to the farmers market this morning, and caught a little rain on the way home. With the new windscreen and roof panel, we only caught a little rain on the forehead & face area. The rest of our body didn't get a drop. Wow, that was different.


This last race I changed the wheel alignment, lowering the camber to -0.5 degrees so I can plant the whole tire on the road during the corners.
Also raised the caster to 9.5, so that the car will track better at highway speeds.
View attachment 25151

Hey @Ross hope you are doing well. I picked up a second set of wheels with some 15” 275 Hoosier A7’s over the winter months and I was doing some digging of potential alignment changes. Is this detail for you Hoosier setup? Do you recommend this for autocross and this setup over the DF recommended setup?

 

[Ross]

The DF recommended setup was for normal width tires. Those 275 Hoosier A7s are a lot wider, so yes, I would recommend putting the camber at -0.5 degrees. The caster change didn't do much as far as I can tell. I was trying to get my goblin to track straight better, but I think the goblin is just so light on the front end, that the tire traction is hard to overcome with caster. But play with the settings yourself, put some chalk on those tires, and see where your tires are wearing. Try to get some heat in those tires before your autocross laps. Some races I could play on a dead end road, and preheat the tires. Most races I had to wait in line, so the tires were pretty cold.

 

[Ross]

Balance shaft delete:
Level Zero Motorsports sold me part B, which plugs the oil flow at the back of the balance shafts.
I made plug A out of some 20mm round stock, to plug the front of the balance shafts.
I didn't like the usual method, which involves cutting the balance shaft at the the green line, which keeps a shoulder on one side, and using the sprocket for the other side, along with bolt 3 to hold it all to part 4. All this just to plug the oil hole at the yellow arrow.

I also drilled some bolt holes in the exhaust flanges, while waiting for the exhaust pipe to come in the mail.

 

[Ross]

I drilled and tapped a M4 hole thru the aluminum bushing, into the steel 20mm plug I made.
The little M4 bolt will keep the plug from moving. Needs some red loctite, as I wouldn't want to loose my oil pressure.

The mandrel bent exhaust pipe arrived today, so I made a template, and cut 120 degrees out.