Daily Drivers with Hi Compression

**WhiteAP1** · 14-08-2007 06:33 PM

The blocks been sleeved with Darton sleeves, Oversized TODA pistons (which is mostly responsible for the CR rise),and the bore is around the 88mm mark. A thinner head gasket from Cometic, a set of F22C valve retainers from the US that are heavier and stronger and a set of TODA valve springs with a slightly shorter coil. OEM rods are forged and pretty decent no real need to change them unless i was going to stroke it, and theres not much advantage to gain with aftermarket cams compared to stock (For my current setup anyway)

**krogoth** · 14-08-2007 11:15 PM

subscribed

**TODA AU** · 15-08-2007 07:53 AM

Originally Posted by WhiteAP1

The blocks been sleeved with Darton sleeves, Oversized TODA pistons (which is mostly responsible for the CR rise),and the bore is around the 88mm mark. A thinner head gasket from Cometic, a set of F22C valve retainers from the US that are heavier and stronger and a set of TODA valve springs with a slightly shorter coil. OEM rods are forged and pretty decent no real need to change them unless i was going to stroke it, and theres not much advantage to gain with aftermarket cams compared to stock (For my current setup anyway)

Ok, time for my 5c worth on that,

The largest F20C piston comercially available through TODA is 87.50mm.
Darton sleeves are not required unless the bores are beyond reconditioning limit.
Further, the factory gasket is very vary good. 0.6mm (0.0236) & should be use together with TODA pistons in the F20C engine.
The cometic gasket is actually thicker at 0.76mm (0.030")
Further the bore of the Cometic gasket is 89mm.
This difference in gasket to bore can cause problems in high compression engine combinations, the larger the difference, the greater the liklihood that you've get either detonation or areas of unburnt fuel.

Regarding F22C valve spring retainers, if these are actually heavier then this is the wrong way to go, regardless of perceved increase in strength.
Use the original retainers with TODA valve springs (Or a quality ti ret)

Regarding Darton sleeves & the F20C
The F20C piston protrudes from the block already, add any machining to the cylinder block surface which is almost guaranteed using the sleeves, if it's just a very light skim, it's all good. If a significant amount of material needs to be removed, unfortunatly you've now started to created a problem that can't be solved without resorting to custom pistons with an alternative installed height.

Regarding OEM rod,
You'll need to change the small end bush to use a forged piston on these.
Press fitting a floating pin will eventually result in engine failure.

Regarding changing cams...
Drop in a set of Spec A2's & you see an extra 10kw at the wheels...
For an F20C, that's an exellent gain.
(std bottom end & std ECU - more with VAFC II)
With higher compression you'll get more with larger cams.
(& an ECU + tuning)

Cheers

Adrian

**tinkerbell** · 15-08-2007 10:09 AM

this is my only input:

hope it helps

**WhiteAP1** · 15-08-2007 11:16 AM

The largest F20C piston comercially available through TODA is 87.50mm.
Darton sleeves are not required unless the bores are beyond reconditioning limit.

Hey Adrian, U propbably dont remember, but i spoke to you a few weeks ago, I was having trouble getting the compression ratio down to a reasonable rate. Thats been fixed now, thanks again for ure advice. Yeah the sleeves are only in because there was some serious cylinder scoring too deep to be honned. The pistons are 87.5mm spec,sorry if i threw anyone.

Further, the factory gasket is very vary good. 0.6mm (0.0236) & should be use together with TODA pistons in the F20C engine.
The cometic gasket is actually thicker at 0.76mm (0.030")
Further the bore of the Cometic gasket is 89mm.

Ive got nothing against the OEM gasket, the Cometic gasket comes with the sleeve kit and is recommended for use. Searching on the net,i also was under the impression cometic gasket came 89mm. I brought this up with my builder and he assured me there were a few specs and only an appropriate size will be used.

Regarding F22C valve spring retainers, if these are actually heavier then this is the wrong way to go, regardless of perceved increase in strength.
Use the original retainers with TODA valve springs (Or a quality ti ret)

Too many cases of AP1 retainers cracking (due to bad driving or poor adjustment or whatever) The F22 retainers fit perfectly, and i came across many well documented builds form credible sources, with improvment and longevity with F22 retainers in F20s. So far no one with the F22 retainers has seen them crack in an F20.

Regarding Darton sleeves & the F20C
The F20C piston protrudes from the block already, add any machining to the cylinder block surface which is almost guaranteed using the sleeves, if it's just a very light skim, it's all good. If a significant amount of material needs to be removed, unfortunatly you've now started to created a problem that can't be solved without resorting to custom pistons with an alternative installed height.

Heights fine, all tests have come back good, there was no excessive surface machining.

Regarding OEM rod,
You'll need to change the small end bush to use a forged piston on these.
Press fitting a floating pin will eventually result in engine failure.

I'll look into that, but arent the OEM pistons forged???

Regarding changing cams...
Drop in a set of Spec A2's & you see an extra 10kw at the wheels...
For an F20C, that's an exellent gain.
(std bottom end & std ECU - more with VAFC II)
With higher compression you'll get more with larger cams.
(& an ECU + tuning)

Ive heard too many mixed reports. Most Ppl with the product state is a waste of money, and those selling it say its an excellent mod. I guess i cant believe everything i read. Im sure poor instillation of the product could be a factor, or a bad tune, but ultimatley i'll have to see for myself.

**TODA AU** · 15-08-2007 12:51 PM

Originally Posted by WhiteAP1

Hey Adrian, U propbably dont remember, but i spoke to you a few weeks ago, I was having trouble getting the compression ratio down to a reasonable rate. Thats been fixed now, thanks again for ure advice. Yeah the sleeves are only in because there was some serious cylinder scoring too deep to be honned. The pistons are 87.5mm spec,sorry if i threw anyone.
Ahhaa, the penny droped... LOL, no worries.

Ive got nothing against the OEM gasket, the Cometic gasket comes with the sleeve kit and is recommended for use. Searching on the net,i also was under the impression cometic gasket came 89mm. I brought this up with my builder and he assured me there were a few specs and only an appropriate size will be used.
Fair enough, I was also under the impression that only 1 gasket was available as there is only 1 PN listing for all F20C & F22C engines.
Too many cases of AP1 retainers cracking (due to bad driving or poor adjustment or whatever) The F22 retainers fit perfectly, and i came across many well documented builds form credible sources, with improvment and longevity with F22 retainers in F20s. So far no one with the F22 retainers has seen them crack in an F20.
It's likley the cracking retainer is more to do with assembly error or setting than the product itself. I'm yet to hear of a genuine warranty claim on an OEM retainer in an F20C.
In any case, if these have been used without issue, all good.
Heights fine, all tests have come back good, there was no excessive surface machining.
Exellent - Good to hear.

I'll look into that, but arent the OEM pistons forged???
The OEM piston is forged, however it uses a press pin. (Std with most Honda OEM pistons)
The TODA pin is a floating pin, hense the need to bush the small end of the rod.

Ive heard too many mixed reports. Most Ppl with the product state is a waste of money, and those selling it say its an excellent mod. I guess i cant believe everything i read. Im sure poor instillation of the product could be a factor, or a bad tune, but ultimatley i'll have to see for myself.

True, true...

**EGB18CT** · 15-08-2007 03:45 PM

erl superdeck block and endyn head FTW... very interesting thread...

**WhiteAP1** · 15-08-2007 05:58 PM

It's likley the cracking retainer is more to do with assembly error or setting than the product itself.

More so,most failures occur due to over reving and the like. Even though they've cracked(mainly hairline cracks), most still drive without realising. With some u cant even tell untill the valve cover is off and they're closley inspected.

The OEM piston is forged, however it uses a press pin. (Std with most Honda OEM pistons)The TODA pin is a floating pin, hense the need to bush the small end of the rod.

And of course this bush doesnt come in the TODA piston kit does it...lol If u could point me in the right direction to grab hold of a set, that would be great.

**TODA AU** · 15-08-2007 06:03 PM

Originally Posted by EGB18CT

erl superdeck block and endyn head FTW... very interesting thread...

Or DART tall deck B20 - we just recived ours for an engine in the pipeline.
It's just sexual chocolate ha ha...

**TODA AU** · 15-08-2007 06:09 PM

Originally Posted by WhiteAP1

More so,most failures occur due to over reving and the like. Even though they've cracked(mainly hairline cracks), most still drive without realising. With some u cant even tell untill the valve cover is off and they're closley inspected.

Ok, fair enough. The cracking in this case would be caused by the exhaust valves touching the pistons whenthe engine is over reved on a down shift & the valves float.
Find out if the cracking only occurs on the exhaust side, this would confirm this thought.
(It's hard to imagine any other way to cause such a failure)

Originally Posted by WhiteAP1

And of course this bush doesnt come in the TODA piston kit does it...lol If u could point me in the right direction to grab hold of a set, that would be great.

LOL, no it's not included...
Your machinist should have no problem sorting this out for you, the going rate is around $250 for a set of 4 rods. If you get stuck, we can get this sorted out for you.