Fred's 2374 -> 2258 Engine Build Thread Options

[Ninja]

Heads up if you didn't know...

Rings can be made from different materials, and each has a different specific RMS (bore finish) to work properly.

I choose the rings before I have the bores finished and tell the machine shop what they are. I always send the new rings so the machine shop can check themselves.

The difference between cast iron and chrome steel rings; cast need ROUGH and chrome needs SMOOTH.

Important for the machinist to know!

Important for the machinist to ASK if he didn't know.

If he didn't ask would be a gigantic red flag for me...

[friethmiller]

Side clearance is CRITICAL!!!

When you measured .0025 difference in the thickness my first thought was, I hope one of those falls between .001-2 to the piston.

SO MUCH BS on how this stuff is fitting together for you!

Make you wonder if ANY of the critters supplying parts actually "give a shit" if the final engine will live.

I feel your pain!
(IMG:style_emoticons/default/ninja.gif)

Yeah Rick, the Hasting rings are suppose to work for these pistons but by the time I got the Piston to Cylinder Wall gap correct, the ring gaps increased by a magnitude of PI. No worries. There's plenty of things I can still do till it gets sorted out. I doubt this will cause much delay. It's just a shame about the side clearance, the Grant rings were around a .015" ring gap out of the box and could have certainly been opened up to meet the .017" spec. I did enjoy doing the head-to-head measurements. (IMG:style_emoticons/default/biggrin.gif)

[friethmiller]

Heads up if you didn't know...

Rings can be made from different materials, and each has a different specific RMS (bore finish) to work properly.

I choose the rings before I have the bores finished and tell the machine shop what they are. I always send the new rings so the machine shop can check themselves.

The difference between cast iron and chrome steel rings; cast need ROUGH and chrome needs SMOOTH.

Important for the machinist to know!

Important for the machinist to ASK if he didn't know.

If he didn't ask would be a gigantic red flag for me...

Interesting. I'm working with the JE rep now on what they recommend. I'll ask Eric (machinist) about the honing surface. They had my rings originally but not on the recent rework to hone them out for the pistons.

[Jack Standz]

We didn't use to have the knowledge and tools that are available today. Theories and hard research are now being exploited by those who know and pay attention.

Would send you some links, but am not able to right now. However, your machinist should use a profilometer. Powell Machine has some good YouTube videos that show how to dial in an aircooled cylinder bore/hone (jet ski or motorcycle engine, can't remember). Also, Lake Speed has some that discuss ring gap that are very good.

If you can set the gap where you want it, based on sound experience, that makes a lot of sense. So, patience pays if you can wait and regrind the ring gap to exactly where you want it. However, if you can't, those gaps are very probably ok. They aren't horrible and aren't likely to be an issue (refer to the videos where Lake Speed discusses ring gap - a tight gap can destroy things and gap, even if it seems excessive, doesn't automatically lead to excessive blowby or a meaningful loss in power).

[friethmiller]

...refer to the videos where Lake Speed discusses ring gap - a tight gap can destroy things and gap, even if it seems excessive, doesn't automatically lead to excessive blowby or a meaningful loss in power...

Thanks John. I've seen Lake's video about ring gap but I may need to revisit. I worked with one of the reps from JE Pistons yesterday. A guy named David. Apparently he's worked with a couple of Porsche race teams in the past. Cool guy. He recommended the same Hastings rings that I had found and ordered from Walmart online [of all places] yesterday morning. It's an oversized 3.78" ring set, which is the next size up. The rings should be here on Saturday with just normal FexEx shipping. That's way faster than any other source I could find and the Walmart price was lower too. We'll see. (IMG:style_emoticons/default/smile.gif)

[Artfrombama]

He recommended the same Hastings rings that I had found and ordered from Walmart online [of all places] yesterday morning.

I used Hastings rings on the top end overhaul of my 1.8. Broken in immediately and no blowby or oil consumption so far (Knocks on wood).

[friethmiller]

Guys,

Well, the oversized rings are good on side clearance but not on back clearance! I'm flush on the number one ring. Thinking about punting and just going with standard rings that have gaps a bit wider at .021" and .024" for #1 and #2, respectively.

[friethmiller]

Building Out the Long Block - Part 1(10/3 - 10/4/2026):

Deck Height and Pistons to Valve Clearance:

While waiting on the oversized rings, I decided to keep my feet moving on other things. With the pistons in #1 & #2, I verified a deck height without shims where the piston was crowning over the top of the cylinder (expected with a 78mm crank). Shooting for between .040"-.045", I added shims to finally settle on a .044" of deck height. This keeps me at the goal of 9.2:1 CR. Next, was the valve clearance check with the shims installed. After getting max lift from both intake and exhaust valves, I verified at least .089" of clearance for the intake and twice that for the exhaust. It's amazing how just a small valve relief (0.9cc) makes such a big difference. (IMG:style_emoticons/default/aktion035.gif)







Installing Pistons & Cylinders:

With the oversized rings a bust and advice from others including the JE rep and Jack Standz, I decided to just go with the rings I had. Having a few extra thou of gap isn't going to be a problem, IMO. It just means I can drive like I'm on the track! (IMG:style_emoticons/default/driving-girl.gif) Anyways... here are the rings going on and the cylinders going in. I followed the instructions on where to clock the different rings on an air-cooled engine.





This next photo shows how not to insert a snap ring into the piston. This was for photo-purposes only. The 2nd photo shows how to properly prevent your snap ring from entering your engine (IMG:style_emoticons/default/biggrin.gif) Luckily I didn't have any mishaps.



Valve Geometry:

With the head installed and torqued, I then set about checking the rocker alignment on the valve stems. The first photo shows the set of shims I used to get the rockers in a reasonable spot on the stem. The 2nd photo shows a typically alignment with the aluminum spacer and standard .040" shims. The 3rd photo shows the end result where shims were switched out and placed in different spots to get a better alignment.





Next up was the big task of verify valve lift and valve geometry in order to zero-in on a push rod length. The following photos show just a glimpse of what took several hours to do. Here, I am working with an adjustable aluminum push rod to get as close to the max lift as possible while maintaining correct geometry at half lift. The second photo shows a quick geometry check to verify I'm adjusting in the correct direction and I've got good alignment.



Cutting Push Rods:

Once I finalized the numbers, I then had to figure out where to cut the push rods. This is definitely where you want to measure 15x before cutting anything. These heavy-duty Aluminum pushrods are not cheap! (IMG:style_emoticons/default/blink.gif) This process of cutting, sanding, and remeasuring took several hours to do. I was so worried about over cutting the push rods that I ended up sanding forever to make sure I eased into my target length. Note: sanding the ends was done on a sheet of glass to help keep things as flat as possible.



Push Rod Tubes:

I ordered these from Tangerine Racing and was a little hesitant based on the price. Let me tell you... these are super nice, sturdy, and worth every penny. Thanks Chris!



Part 2 coming soon.