Unless he runs the Toda timing chain and matching TCT. Still, OEM is 100% great with the longevity to boot (maybe not most people's stock TCT's lol)

 

Also called "milling" the head...? He'd rather not. Billman says not to mill these heads. I wouldn't trust machine shops to get an S2000 head right. It's best for him to get a new/used good head or better yet get a whole replacement engine that's in good condition and unopened.

 

Hmm. I simply dont get it. Beside the FRM cylinders, it´s a ordinary 4 cyl. Tolerances like every Motorcycle engine.
All these details are written in the workshop manual from Honda. Detailed and Exact. Just one Example: Cylinder Head resurfacing is allowed up to 0.2 mm maximum, starting from a cylinder head heigth of 105 mm.
It´s all written there....

Did the owners and / or machine shops just dont have the information or did they simply dont read them or do they ignore them ("I know best!") ?

 

The TODA TCT just cures the stupid simple problem of the OEM chain tensioner, it dont change the pressure on the Chain.
I have a OEM and a Toda TCT lying here. The oil pressure feed, hole diameter and pressure regulator valve in the Toda is exactly the same as OEM. It´s the same core / case as OEM.

 

Thanks for posting the machining limit of the cylinder head. Stacking tolerances will have to be considered if any material is to be removed from the top of the cylinder block which might be where these get screwed up. I don't see any information on resurfacing the top of the engine block but I'm still on my first cup of coffee this Sunday morning and can smell the bacon frying so I'm impatient.

Page 6-35 of the Service Manual confirms the maximum resurface limit at 0.2mm (0.008") assuming a 105mm cylinder height. If the cylinder head is thinner than 105mm it appears even less can be removed.

New cylinder height: 104.95mm - 105.05mm There's only a +/- 0.05mm tolerance from 105mm to start with.

Check my math:
Nominal cylinder head height: 105mm
Max resurface: 0.2mm
Minimum modified head height: 104.8mm or -0.15mm from new OEM)

-- Chuck

 

There is no information about the re-surfacing of the top of the Engine Block, only the maximum allowed warpage. When new, its up to 0.07 mm / 0.003 Inch warpage allowed, servie limit is 0.10 mm / 0.004 Inch of warpage.
It´s up to everybody to make his own conclusion and decission.

 

Cometic offers head gaskets in various thickness for the F20C.

 

My s2k has some sentimental value, so it's going to stay with me for years to come. I'm also boosted and realize having a spare motor is a good insurance plan. Unfortunately, motors now are absurdly priced. Used motors are going for more than new ones were when they were available.

The best value proposition I could find is finding a hurt motor for dirt cheap (1500 or less) and completely rebuilding it (I'm in the process of doing this). And by hurt I mean scored cylinder walls or spun bearing with a 100% intact head. If the cylinder walls are scored, you're just a dry sleeve (any competent machine shop can do this) job away from fixing this. Mahle does make a FRM friendly piston, but you'll have great difficulty finding a shop that can work with FRM cylinders. If the crank is toast, you have a couple options: get another OE crank which is around $1k USD or use a k20.

The f20c has an 84 mm stroke and a 153mm rod length. The k20 has an 86 mm stroke and is dirt cheap at around 100 USD. Since the stroke is 2mm longer you need a 1mm shorter rod. As it happens the k24 rod length is 152mm. Unfortunately, the F20's wrist pin is 1 mm larger than the K's wrist pin; however, you can get k-series pistons in the F-series bore. Of course this requires sleeves. Even with all these additional costs, you'll still come out ahead compared to buying a used motor since at the end of this you have a new motor (of known history) for similar money to the used one.

 

No. Milling the head is resurfacing and removing material from the flat area of the head. This is done to make the surface flat. Heads often warp when an overheat occurs. So milling in that scenario is required. Since as you point out, our heads can only be milled a very tiny amount compared to most engines, it means head is junk if its warped.

A side effect of milling is increased compression ratio, as well as the chain geometry issues Billman has warned us about.

cc'ing a head is not milling. Not machining the flat surface, but rather its grinding the combustion chamber, area around where the valve heads are. The idea is to make every chamber exact same size. Called cc'ing because you pour liquid into the chamber of the overturned head, and determine hiw many cc's of liquid it takes to fill it. You grind, by hand, each chamber until they all have exact same cc's of liquid to fill them.

A side effect of cc'ing is compression ratio is lowered.

The point of discussing cc'ing was to show this area of a head is something that can be and is machined. So the damage his head has in this area, basically dents, might be fixable, and machine shops are familiar with the technique to do so. They wouldn't be grinding it to cc it, but rather to remove the damage. Though it'd be a good idea to make some effort to make them all closer to the same, like were stock, after removing damage.

Remainsto be seen if the damage is too great to fix this way, or if it needs fixing at all (or if head has other issues that make it unusable, making this all moot).

 

Oh ok, Did not know that. Toda says their TCT is higher tension