drtalon123

Hey guys, I have some questions about the F23 series engines. I would like answers from people who have EXPERIENCE with these engines. Are the stock internals strong enough for a mild boost application? Mild meaning 7 to 12 psi. I am building a brand new F23/H23 block/head combo for my prelude but I would like to turbocharge it this time. If the stock internals are good enough for mild boost, then I am going to carry on with my build. I am replacing EVERYTHING but if stock bottom end internals are ok for mild boost, then I'm going to buy new stock components for it. Let me know what you think, I appreciate it.

carnot

might be better to talk in terms of WHP goals instead of psi since different turbos can produce different power at the same psi. I would think it would be worth your time and peace of mind to build with forged components.

flyrod

That is going to be a problem; different sizes...

drtalon123

Nope, they work. Have built 2 F23/H23 engine combos before and they kick ***. Just need to know info on stock internal strength. I am not a newbie what so ever to building engines, especially when it comes to measuring tolerance and clearance specs, these two come together just fine

NirVTEC

What do you mean by combo?
The H23 and F23 have different sized cranks & mains. 95/50 97/55
F23 head on H23 block? Why
H23 head on F23 block? Why

Im lost.....

7-12psi means almost nothing w/o Turbo specs.......

Almost scary to think there are drtalon123-BUILT motors out there.

drtalon123

I am using an H23 head on an F23 block. They work. End of conversation. The reasons for such a swap are based on what type of engine you want. I like the F blocks because rather than FRM liners, they have iron sleeves which accept forged pistons without issue. The F23 block is a desirable block becuase it resembles alot of the technology that is now in the K series blocks. The only problem is, there are really no aftermarket parts for it. You can slap pistons from a K series into the F23 block no problem. The reason for an H23 head is DOHC. Greater tuning capabilities, you can also slap an H22 head onto it and that will work too. You just need a VTEC computer and harness to make VTEC work. Other than that, the H23 head is perfect for what I am trying to do, I want a turbocharged engine sometime in the next few months and I am going to build this engine combo. You can also make the F23 a closed deck by buying a block guard off of F22 parts . com and it fits with some mods at a machine shop. Like I said before the F series blocks already come with iron sleeves so instead of having a machine shop rework an H22/23 block to make iron sleeves fit, you already have blocks with sleeves for CHEAP. Again, the block guard can make the F23's open deck into a closed deck which is perfect for someone going high compression/high boost. I'm not. And for the last time, I want to know if anyone has ever mildly boosted an F series with stock internals and made it work ok?

P.S. NirVTEC, have you never heard of the G22 VTEC/G23 frankenstein engine that quite a few people have successfully built? If not, read up on it. F blocks are much cheaper to find and get parts for. And if you are like me and dont have thousands of dollars to play with, this is a desirable engine combination.

92civlude

What comp ratio are you shooting for? Mine is 8.8 to 1. H22 head, Stock F23 slugs. If you go mild boost, 9.5 to 1 would work with a smaller turbo, .48 or .50 trim if your goal is around 290-300 to the wheels. You can use the compression ratio calculator in the FAQ section. It was useful for me.

drtalon123

Yea, the H23 and F23 blocks create a compression ratio of 9.8:1 with a stock headgasket. I'm going to use an aftermarket head gasket that is stronger but a slight bit bigger making the end result compression ratio around 9.7:1 which is ok. The whole reason for me wanting to boost the F23 with stock internals is because I want turbocharger infrastructure on the car that is ready to go and tune when the time comes that I have some extra money to throw at forged internals. I already have fuel map tuning capabilities and wideband O2 sensor equipment, so I technically just need to slap a turbo on it and bring it to the dyno shop. I can pull my engine out of my car with the trans in about 2 and a half hours, so I'm in no way bothered pulling it out and putting it back in... by the time I have money for internals, the block would probably do good for another trip to the machine shop for a good cleaning anyways. I'm hoping it will all work out pretty good.

camshafted

I just finished my frankenstien build recently. I have an H23 head on and F2 block. I heard this combo makes 8:1 compression. Does that sound right? I was also going to turbo it due to the fact that the DSM turbo manifild bolt right up with a little bit of modification to the bolt holes.

To answer your question I believe you should be able to handle 10lbs of boost SAFELY with stock internals.

ilikehonda

why put all new oem parts in the bottom end when you could put stronger forged stuff in there for just a little bit more money? Then you could make more power safely

NirVTEC

Did someone just try to educate me on the H/F interchangable life?
Whats a "G"?

I guess when I think of BOOST, I just naturally think of SLEEVING......so who cares about FRM or Iron!?...
I consider just about anything that can be done with Boost on a stock internal motor to be boring after having ~300whp with Nitrous.....(There are just a few exceptions to that, and GL with reliability) Your average 7-9psi stock H22 couldn't hold a candle to 300whp with Nitrous.
Few $K on a turbo kit for 13s? lulzzz

You have built a few, yet ask about their stength with boost......thats a little suspect.

drtalon123

Thanks camshafted for posting a response based on your experiences. You have stuck with the point of my post and for that, I appreciate it.

Ok nirvtec, you are overlooking the whole point of my post. Unlike some people, I don't have much money at the moment to throw at forged internals. Let me try and put my money perspective/situation out there: I have a 1990 eclipse that took me about 5 years to build properly to the way I wanted it. It currently has around 650 awhp on c16 at 34 psi. It took approximately $15,000 over that 5 year period of time to **** with and get right. This was WAY before I had a family and a son. I no longer blow every dime I have at parts and tools like I did back then. I have built many engines, high revving NA setups and lots of turbo projects. I used to work for a performance and tuning shop but I quit to finish college. Getting back to the point of my post, I WANT TO KNOW IF ANYONE HAS EVER SUCCESSFULLY BOOSTED A STOCK F23 BOTTOM END AT LOW PSI WITHOUT MANY DRIVEABILITY ISSUES. I am asking this question because I personally have never messed with turbocharging an F series WITHOUT internally making it stronger. I have only ever turbocharged a few D and H series engines where the bottom and top ends were stock, and to tell you the truth, they worked pretty good at low boost on 91 pump. The prelude I am going to put this engine into is a toy that I want to mess with OVER TIME, not all at once nor am I looking to go fast with the FWD prelude, I just want a turbo on it. Going fast is what the 4WD Eclipse is for.

So, please quit responding if you are going to ask me anything that has to do with:
1. Sleeving
2. Forged parts
3. Being cocky or smart assed
4. anything else that costs lots of money

Believe me, what I would like to do with this car is FAR from what I have. Getting to where I want it TAKES MONEY, and I dont have much to throw around like I used to (I'm saving for other things). Again, please feel free to respond if you think that it's gonna be safe to boost at anywhere from 7 to 12 psi stock OR if you have experience boosting the F23 stock. If I get more yes's than no's then guess what, I'm boosting the F23. I will then make a post later on about the build and the results.

ilikehonda

ok since you are being a giant dick you can **** off and search this yourself. here is picture for you to follow. You can then just seach f23 turbo, 98-02 accord turbo etc etc etc. you will find your answers there.

NirVTEC

hahahaha
NVM; DSM owner.

slomofo

iTrader: (1)

Assuming you're running a smaller turbo like a Shitsubishi TD05, Garrett T3/T04E (or whatever the fanbois are running these days), 5psi is your safest bet with the stock F23 internals & H23 head. If you want to bump it up to around 10psi, you're going to have to find a good tuner and upgrade your fuel system.

Don't pay too much attention to NirVTEC, he is a really cool guy, but he has been known to get ahead of himself sometimes.

ilikehonda

you are just as dumb as the op. 5 psi doesnt mean JACK ****. psi does not break parts hp does.....make a power goal then build for it...damn. cfm and knowing how to read a compressor map are more important that how much boostsstststs you are running.

NirVTEC

Thanks?

I just get annoyed when people ask questions that have been asked for 5yrs+ and then credential drop.
And wouldn't one guess that "most" F series questions are better aimed at Accord owners?

slomofo

iTrader: (1)

I based my post on an assumption that he'd run an off the shelf turbo from a DSM or an e-bay spec T3/T04E .63 a/r which I'm almost certain he would do because these questions from noobs usually end up with those kinds of turbos. Usually when a guy is looking to boost a stock engine safely, they're doing a cheap build. Cheap builds usually end up with cheap turbos. Cheap turbos usually come from end up being the two turbos I listed. Do you not agree with this?

drtalon123

@ slomofo, the head already has 440cc injectors and a billet aluminum fuel rail. The fuel system has a walbro 255 fuel pump. The car has a proper fuel system for a turbocharger application (the head was built up a while ago and has been sitting in my garage for about a year and the fuel pump is part of a fuel cell assembly that I bought a long time ago, I just recently mounted it in the trunk of the prelude and ran stainless fuel lines to the engine bay ready for hook up.) I have an F22A1 ecu with hondata's S300 in it that im going to use in this car, so I have fuel management capabilities already. Basically my goal is to build the car to the point that everything is finished the way I want it EXCEPT the engine (too much money at the moment, thats what tax time is for lol) so when tax time comes, the money I decide to set aside for the car can ALL go towards the engine and making it stronger.

@nirVTEC, good point about accords. I guess I should have thought about that lol. I guess not too many prelude owners deciding to do major work or tuning to their cars with F series engines in them. Actually, most prelude owners have their eyes set on the H series which is actually what the prelude section of this site is full of. Enough said, I'm going to the accord section lol.

drtalon123

@slomofo, your right I've had a turbonetics setup in my garage for a while which is what I want to use for this. It is a T3/T4, external wastegate, equal length header to turbo, I've also got an electronic exhaust cut out that I want to install so I can use a quiet glasspack muffler at the back of the car when I'm cruising around, but cut it out when I want less back pressure and have a straight pipe that dumps around the rear of the engine bay. Believe me, I want to upgrade the internals of the F23 RIGHT NOW, I just cant. No Moula to throw at it. At tax time, Im gonna upgrade the engine internals and get it retuned for more boost (have a friend who own a dyno shop, free dyno time after hours lol). I already have driveshafts that are good for 600whp and the transmission I bought from a friend about a year ago is a modified F22A1 trans that has 1st, 2nd and 3rd gears are straight cut type with no synchros and the diff is a Quaife LSD. The clutch is an Exedy twin plate clutch and flywheel combo. Most of the parts that are going to make this car pretty nice I already have. The car already has Eibach shocks/struts/camber kits and 16 inch BBS Y-Spokes on potenza 255/50/16's. Everything that this car is and will be, are things that I have collected through the years for SOME type of honda build that I told myself I was going to do. I have an COMPLETELY modified 88 civic hatch and built D16 that revs to 10,800 rpm and makes 235hp at 8000 rpm. I have had this 95 prelude that I got completely stock that I bought when I got my license.

NirVTEC

235whp D16@10,800rpm is something I'd like to hear more about considering most N/A d series guys are stuck in 140-160 land.(My i/h/e@~130whp was considered impressive for what it was)

255/50/16s??? Way to murder the already horrible gearing with the F22 trans.
You should play with this a bit before putting the F22 trans on with 26" tires.
http://teammfactory.com/gear-calculator

slomofo

iTrader: (1)

zOMG! Turblownetics T3/T04E .63 A/R


Who would've ever freaking guessed that? ? ? ?

NirVTEC

I lol'd.
My shop won't even install them anymore because they leak, and Turblownetics will replace the turbo, but NOT labor.
Precision or BW FTW!
****, I'd have more confidence in a $100 14b

ilikehonda

to the op....you do realize that the f23 never came in the prelude? it was an accord motor. there are plenty of guys running f22 turbos in their preludes and accords.

komodomoe

If anyone knows a source for forged pistons and rods for an f23a1, please PM me. It seems like the best I can find is K20a3 rods and pistons which would leave me with a positive deck height of .079 Also, If I'm going to boost can anyone recommend any other good bottom end upgrades?