F23a1 with A6 head

[Thormx353]

The engine is already assembled and running... Here is what he said in of his messages "No issues whatsoever, runs well. Built right with genuine Honda parts and all power adders are oem Honda parts" and here is a piece from his ad "Its an F23A1 with H23 intake manifold A6 Head and Cam, 2.5in stainless OBX exhaust from headers back, p12 ecu. all those parts have less than 10k on them. engine was overhauled bottom to top (have list of parts and receipts). all new tires with prelude si alloy wheels. 8000k HID kit, red LED dash lights. car gets around 32mpg." He is an on the road diesel mechanic and moving pretty far away leaving him to only be able to take his truck. If all is well I'm probably going to bite the bullet and buy it Friday. As for boost or any other mods it will still be far ahead in the future as the Si comes first and I want this to be my dedicated daily. I realize just having a stock rebuilt engine still isn't as good as having forged internals but I wasn't sure how well a newly stock built f23 could handle boost. What numbers do you think this set up is at currently and is there any more room for improvement as far as a N/A street car is concerned?

[wildBill83]

I gotta admit that I like his mod list. I hope the HIDs are in projector housings.

Do your thing man, I hope he isn't talking up a pile of poo though. I'm sure you have the ability to call bull shit based on your previous experience when you see the car.

[deevergote]

The A6 head was very likely a downgrade from the F23A1 head. I wonder why he went that route. Those Prelude wheels will likely rub at full lock. I have the same on my own car.
The P12 is made for the F22A1. It is a TERRIBLE choice for that setup. Doesn't even have IAB control.

All those parts are considered "upgrades" in one way or another to an F22A1... but together? It's like saying "I love steak sauce! And chocolate sauce! And Pepsi!", then throwing it all together in one big glass. Great separately, perfect additions when used appropriately... TERRIBLE when mixed together haphazardly. Honestly, it sounds to me that this guy just threw together a bunch of parts without giving any consideration as to whether or not they'll even work together. That makes me wary of the quality of his work, regardless of what parts he used, or what he does for a living.

[Jarrett]

In it's current form I'd say it's probably putting about 135-140whp down on a Mustang dyno. It should show low at the bottom end because of non-functioning IABs (The P12 cannot control them).



To Deev's point:
While I do show support for this combination, the mere fact that it was reassembled means that you must ensure that you trust the person's work. While the combination of a F22A head on an F22A block is a no-brainer from a compatibility standpoint, someone who is incompetent assembling them can create something just as unreliable as two components that were less compatible.

[deevergote]

Even a rebuilt F22A done in a mechanic's spare time could have issues... taking on someone else's project is ALWAYS scary.
Having a professional rebuild an engine for pay is one thing. You're paying them, and there's a certain level of accountability. But when it's a personal project, there's no accountability, and no guarantee that he even cared (though the meticulous nature of ordering only Honda parts and saving receipts is a comfort.) Hell, dude could've been building that engine over the course of a few weeks while pounding a 12 pack in every wrenching session!

[Thormx353]

So what would you recommend, aside from the block/head combo, about which parts to use. It seems like the only area of concern here is the IM and ECU choice. I think we all understand the risks of buying someone else's work but unfortunately it's something we have to deal with in the car enthusiast world. Even buying something stock though doesn't mean it's been taken care of well.

[deevergote]

That is also true.

The IM is good. I would go for a PT6 ECU (the F22A6 ECU) to at least control the IABs. It still won't be right, given the bottom end... but way better than the P12.

[8ball]

Are you buying the car already running or just the engine? If just the engine steer clear or be extremely cautious .

If its the car, well you know the drill just turn it on, let it idle for the entire time you two talk about the car. And focus on shit like weather stripping, poorly tinted glass, misaligned body panels all the bad shit on the car that way you dont trick your mind into saying "oh wow what a cool engine" and end up with a head ache.

After its been idling about 15-25 minutes no less tell him you are intrested in seeing how it drives. Let him drive around for 5-10 minutes, if he drives aggressive thats a bad sign. If he drives OK and the engine oil is ok thats a good sign. Now when you get into the car turn on the lights roll windows up make sure all the electronic shit works. And if you have the A/C available turn it on edven if its cold. It adds load and stress to the engine. Pick a place with hills or stop and go places it adds more load. If it over heats or does anything funny steer clear the car has been running about an hour that should be a walk in the park for any healthy engine

[cb7ronnie]

I'm th3 Guy a few threads down with this combo + a turbo...I've had this setup installed for about 2 weeks and I'm having problems with either timing or ecu, I haven't had time to check into it to much as for a hectic work schedule and recent death in the family...but even with the current problem I still dd her about 20miles a day..but ill be setting the timing again tomorrow to see what I get and ill let you know how it goes

My setup
full port and polished f22a6 head with port and polished h23 intake manifold with spacer I believe an omni 68mm big bore throttle body and skunk2 adjustable cam gear 450cc dsm injectors t28 Garrett g25 turbo 3" cold side piping with 2.5" hotside and a stock f23 bottem end

This is temporary till I finish the f22 bottem end so say wat you please

[Thormx353]

Some more info on the car. "h23intake mani upper and lower butterflies gutted. chipped p12ecu." Taken from a a little more in depth ad that was one of the car groups I'm in on Facebook.

[Jarrett]

The P12 is not capable of being chipped with conventional methods so unless he's added IABs or converted it from auto to manual it
s flat just not chipped.

[deevergote]

Unless he added some cheap ebay resistor... which would be really scary.

As mentioned before, the gutted IAB will actually decrease low-end power. That pretty much contradicts the whole reason for doing the F23 bottom end!
I would get the PT6 ECU, and source a functional IAB plate. Use the gutted one as a spacer.

[toycar]

Cam duration in an interference engine (most Honda engines, for example) is limited by the stroke of the engine. The piston inside of an engine with an increased stroke will travel away from TDC much faster if it is to complete the same rotation as that of an engine with a shorter stroke at a given rpm.

Though piston speed is increased with a longer stroke and your theory about valve timing is accurate, dwell times are actually increased with longer stroke as well.



Not trying to start ANOTHER debate over engine building, but I thought dwell times are worth pointing out because your paragraph doesn't really cover that and sort of indicates the opposite. Yes piston speeds are faster with a longer stroke.


Longer dwell times are due to the greater overall circumference of the rotation though, which is a bi-product of the longer stroke. The diameter of the circle that the crankshaft spins in is larger with a longer stroke, so the duration it spends at top and bottom is longer.

This is actually a good thing with a N/A motor as it allows a longer period of time for fuel atomization and makes a better burn in the cylinder(n/a only)


Again, just wanted to point that out since you didn't mention anything about dwell times in your post.

[Jarrett]

Thanks for pointing that out. I chose not to mention it as the post wasn't really intended to show off what I know about engines but to cover aspects of the longer stroke that dealt with camshaft duration within a simplified scope.

I do recognize the important of the concept with cam selection, though, and it will be a major consideration when I finally go to choose my camshafts for my own build. Piston dwell times will be increased even further than what is caused by the longer stroke.