TurboToyotas

Nothing!!!.........................got your attention

Ok, I stared this thread because another thread was getting off topic. (the ? for ZPI regarding there engine packages)

But a conversation I think everyone needs to see and be apart of is the whole topic of a built motor and the myths that go along with it.

I'll start off with a few comments and see how things go from there:


A built motor only allows you the ability to make more power than the stock motor can handle.

Unless the built motor is bored/stroked and running higher compression pistons than a stock motor it does not make more power than your stock motor would.(comparing the same setups)

What about headwork?

Are you going to make more power just by getting your head ported/polished?

the answer is no. To take advantage of headwork you need the rest of the components that all you to capitilize on making your head flow more air.

better cams, better intake manifold, upgraded valvetrain so you can safely rev higher that your stock components will allow. Its a fine balance of the right parts that make headwork really work.

I'll start there....

Let the fun begin

Regards-

Todd

Crippie

"A built motor only allows you the ability to make more power than the stock motor can handle.

Unless the built motor is bored/stroked and running higher compression pistons than a stock motor it does not make more power than your stock motor would.(comparing the same setups)"

???

Brett

a built motor also makes you 10 times cooler, and you can speak telepathicly with animals. the only thing that could possiblly trump a built motor is a gigantic APC sticker across your front winshiled.

TurboToyotas

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If I take the same motor(bore etc) and put rods pistons in it(built) with the same setup as a stock motor they are going to make the same amount of power.

The only way a built motor makes more power with the same setup is if its bored/stroked or running higher compression than the stock set up.

Hope that helps.

Regards-

Todd

engifineer

Maybe you are talking about the tC more specifically, but p n p heads WILL make more power on thier own depending on application. On the tC, I wouldnt expect too much, but on many cars there is a lot to be done with the heads that will make more power on thier own. These little 4 bangers come with pretty decent port matching compared to a lot of engines and dont benefit as much.

As far as the rest, I am not sure who thought that simply building the motor strength wise would make more power... havent heard that one before. Obviously it wont. That takes a build including more, like higher compression etc.

Brett

one way i can see a p&p head making a big difference is if you are runnig high boost on a car and your power plateaus because of a restrictive head. but like tood said, there are things before the head like intake mani, and tb that must be upgraded as well to reach the full potential of a p&p job.

paul_dezod

Not 100% true Todd. On a positive manifold system you can see gains for a port job, but this is heavily dependent and contingent upon how clean or fudged the ports are to begin with from the factory. For example, on the D17, we did some decent porting on the head with a 100% stock cam profile and IM to get 44whp on the same boost level. The additional CFM picked up from a decent port job will show dividends for sure on a positive pressure system (assuming it is all done right, on a flow bench and not just some dremmel happy fool), however to get the most out of the car, cams, IM and others components need to be utilized.

BuddhasTC

thanx Turbo...maybe the others will follow

pollup

its true about cams and heads. just dependant on the motor. camaros usually see somewhere from 30 to 60whp from heads and cams..

Joe_Dezod

THANK YOU FOR THIS THREAD!!!

Mostly accurate, definately the best explained for the brief discription posted.

I notice the other thread state that a built motor flows better? To address that issue... Building the motor generally refers to pistons and rods. This doesn't alter air flow characteristics. Porting the head, changing lift duration, cam profiles, etc change the flow.

Rythm's argument that a built engine with 10psi will beat a stock engine at 10psi is total BS. Yeah the built motor will last longer, but assuming the built motor has lower compression, it will make less power. As stated above though, if the stroke, bore, or compression is increased, power naturally goes up, assuming other variables are fixed.

This is just way too much to simply describe in a simple post here and there. I think that's why everyone is arguing about it. It's being left a little vague (for good reason lol).

pollup

if im not mistaken rhythm meant in the same conditions. alot of people are misreading what is being written over there. so let me clear it up.

2 tc's
dezod stage 1 kits.

both running the same tune at 10 psi.

car 1 takes his motor out and has it built.
car 1 puts that same motor in and directly goes to race car 2. it will lose. he will be generating less power because of the lower compression. but he will have the ability to generate more power overall by retuning and turning up the boost.

this is how i understand it to be.

FIREDOG

yup..

318_tC

very true

engifineer

I am amazed that this was an argument somewhere... I just assumed that people understood that under the same conditions you will gain no power from a "normal" build (rods, pistons, etc) if the same characteristics were adhered to. Seems pretty common sense for anyone who understands an engine But, thanks for clearing it up for those who thought otherwise!

rhythmnsmoke

Whooa, dude. That was not me you are quoting. I agreed on the statement that Pollup was saying from the aspect that if you slapped both on the dyno and EVERY, and I mean EVERY other variable is the same. (I.E. PSI, A/F, timing..etc). I believe everyone is understanding that the stock block motor is going to pump out a higher amount of HP than the built one does.

NOW when it comes to racing, I didn't say the Stock block will beat the Built one. Because the built guy can go where the stock guy can't. So, it wasn't me saying this, if you go back to the other thread and read. You think I'm going to turn my boost down to handicap myself just because the other guy does not have a built motor....HELL NO! This Ain't Pinks where you ask for 10 car lengths to make it fair....


The problem is that people are saying "if it stays the same". Who exactly is going to run the same PSI and have the same tune after going built motor? I for one am not.

rhythmnsmoke

It was my understanding as well, that you didn't need ALL of those other components just to utilize a high flow head. Increasing the rev limit in itself I thought was the by-product of having a high flow head, among increase in air flow. Don't need an after market intake manifold, cams, etc...to do that. Although it would be nice to have those parts.

Joe_Dezod

Ok cool.

At least everything is cleared up in this thread and we can all say cheers to boost.

I'll upload some details of the build we're working on soon.

lowandslow2

when i had my mustang I bought a set of heads from a guy that told me they had been worked wasent sure what he ment so he let me take em down the track it took 3 tenths of my quarter,I also had a edelbrock cam so that might been a combo thing. way off topic but what ever.

paul_dezod

The cams, IM, valves and such can be used to complement or complete the equation of the PnP head. The head may need a particular air flow, which can only be delivered from a particular IM design, and might need a particular cam to accent and throw the air into it's peak zone of flow faster. There are MANY sub-lets of a 'perfect' air flow head design.

Increasing revs can be futile if the cam, IM, valve train and head do not support the power. No sense in revving to 8K if you power band dies at 6K. Your wasting your time and effort.

Menace

Great post guys...