Making head swap, Question about Revs

**Arashi666** · 03-10-2007, 10:55 AM

OK so Im deciding to go with a head swap on my CL, in favor of a DOHC setup.......... now the question is, how high should the revs go, should it rev to the specs of the new head's engine or the revs of my stock engine block, id assume it would be to the head's specs........ but im not so sure

in terms of structural stuff its commonly known amongst Honda enthusiasts that my current block (F22) is stronger than the block of the head that im getting (H22), so it'll probably be able to take the stress that the H22 block would take, and then some......... as for the VTEC, im sure its all up to the Head's specs on the engagement point and all that......... im sure if I were to rev to the levels of the head that I would want another ECU for the H22......... that much im sure of, other than that all other stuff will more than likely bolt up and all wiring should properly plug up

OK after a lookup of the specs heres what I got

H22 as a whole develops peak power at 7000 RPM........ thats right where the F22 cuts off the revs (I dunno if its a fuel cut or a spark cut).. so If it were to rev to the Block specs.... it would almost be pointless of an upgrade

**TSi+WRX** · 03-10-2007, 11:48 AM

Way out of my shallow knowledge pool on this one, bruddah!

ops:

Just wanted to wish you good luck!

**hsilman** · 03-10-2007, 11:57 AM

rev limits are controlled by the ecu, and AFAIK they don't adjust to mechanical changes in the engine. AT least, none of the computers in cars I have worked on(DMC mostly) do it. It's possible you can "chip" or whatnot to get it to work, but I'm unfamiliar with that.

Personally, if you're gonna do that much work, and have enough cash, you might want to think about getting an independent engine management system and be done with ecus at all. I highly recommend Mega-Squirt if it is compatible with your engine, it works wonders on neons.

edit: another option is ecu swap, but I don't know anything about your type of vehicle, so I don't know how simple that is. It might be as easy as simply swapping computers, but it might require a different wiring harness all together, which would be a huge pain.

**Arashi666** · 03-10-2007, 12:54 PM

best standalone ECU units for my sort of application would probably be AEM E-Manage, and Apexi Power FC......... not exactly cheap, but it would be the best way to do it............ I was just wondering where the rev limit would be, for the new head or the old Block????

**Kremithefrog** · 03-10-2007, 03:30 PM

Get on honda tech.

And don't you have an automatic? Just save your money and get one with a manual, or better yet skip that step (many of us go through these steps) and just go to a manual, rwd, sportish car. Unless you spend a lotta money on that car, it won't be fast so they're really ain't a point.

**Arashi666** · 03-10-2007, 04:46 PM

OK.........1st off, I HATE HONDA TECH......... filled with little loser funded by mommy and daddy, and all they ever do is wanna show off their ****......... I read, but thats it

and as for the 2nd thing...... dont think I havent realized that......... but I'm asking a question, if you can't answer it properly, or atleast havee something positive to say......... well then its not neccesary

**wanderingmind** · 03-10-2007, 09:29 PM

Originally Posted by Arashi666

and as for the 2nd thing...... dont think I havent realized that......... but I'm asking a question, if you can't answer it properly, or atleast havee something positive to say......... well then its not neccesary

I think he brought up a relevant point.

How much hp/tq are you going to gain from the head swap? It can't be that much and it's going to cost a considerable amount of money.

Have you thought about N2O? That is by far the best bang for buck there is. If installed correctly and used wisely, it is very safe.

**stray444** · 03-11-2007, 03:11 AM

you got to upgrade the internals though with N2O. even if you use it wisely.

**NooB1FieD** · 03-11-2007, 08:35 AM

Originally Posted by wanderingmind

If installed correctly and used wisely

I and I am sure many others would "lack" the ability to control ones self in the event that they need/want more hp.

:twisted:

**edweird** · 03-11-2007, 11:03 AM

Originally Posted by Arashi666

how high should the revs go, should it rev to the specs of the new head's engine or the revs of my stock engine block

Certainly there are things in the lower part of the engine that have an effect on the rev limit. The rods and the crank are the first two that come to mind. Motors designed for higher revs will use stonger material for these parts, and often have changes to the oiling system. Also, things like your oil pump, and all of the belt driven accesories on the front of the motor were designed or tested with the original rev limit of the motor in your car.

As far as the new head goes, it's valves and springs and cams and other stuff were desgined for it's rev limit.

I'd say the safest thing to use would be which ever of the two's limit was the least. That's general advice, and not specific to Honda's. Someone who knows more about part's interchange and other stuff might know if the same crank and rods that are in your original engine were used in the DOHC motors.