Hi Performance Head

[MIGHTY 8]

Hello all,

General question...

Say someone offers to "build you a head with all the bells and whistles" for you.

Assuming nothing else is done and keeping the focus on the performance potential of the head alone (I.e. not to drag the discussion into whether exhaust and/or other areas have received attention...)

What is the potential gain here going forward? And more technically specific, what would you insist on to be done to insure that maximum edge?

To be fair, I have addressed other areas to include exhaust, flywheel, and cams. But short of over-hauling the engine to include new pistons and such, my question is to see if simply "slapping" on a HiPo head in the meantime is recommended or if its better to accomplish only when completely re-building the motor.

Thanks in advance.

[BEEK]

as a builder of high performance engines and cylinder heads., these are my thoughts. simple explanation

a full race head, ported and polished, big valves and all the bells and whistles will not gain much if you do not have the supporting mods. the object of a "race head" is to create a better flow. to use this flow you will need the supporting mods, larger carb, or throttle body, multiple carbs, proper exhaust, better camshafts and above all more compression. when you add camshaft (longer duration) you decrease the dynamic compression of the engine. you will need to increase the static compression to overcome this. and the other thing you are trying to gain is more rpm's. the more power strokes per minute makes more power output

so you can do all the bells and whistles to your head and you will see a marginal gain in the performance, you could see a loss at lower rpms. but why not. especially if you are planning to improve the bottom end in the future. cam timing is another big issue, but that will be volumes in itself

[So Cal Mark]

the condition of the long block should also be considered; if you have worn rings, etc you might not see any gain at all

[narfire]

Carb'd or FI engine?

Anyway I, like most would agree with Beek with one addition in what made a noticeable difference for me was to have the(new) cams/engine degreed in properly . I drove it before degree...pretty good and then after, holy s... hard to believe it was the same engine.
Chris

[fiatfactory]

.

[BEEK]

steve just gave you a technical education with regards to your answer, i was trying to keep it simple for the average user to understand. Great explanation.

[MIGHTY 8]

SteveC and all,

I graciously thank you for your replies. Little by little we all gleam some insight by informative responses such as these here.

I can first say the "bells and whistles" comment was of my making and not the proposed engine builder's words! I just wanted to pick a n expression to "sum" up (and inevitably, but not the intent) to dumb down the question to direct the conversation back to the point.

Point is this.

1. To the best of my knowledge engine is in good state, CR readings "ok" on all pistons-and pulls strong, no smoke.
2. Trusted local Fiat enthusiast with tons of experience is available to provide said work.
3. General idea would be drive car to be dropped off and have this person "work his magic!" Damn, I'm sorry if I lean to waxing poetic!
4. Point is, it wouldn't be just throwing on some random head without the common sense of the fine tuning and adjusting that must be done to insure all components complement themselves.

Car is currently running dual 40 IDF's, 40/80 intake & exhaust, Mark's 2.5" exhaust, and Miller's Mule light Flywheel.

Since I'm not ready for an outright total rebuild. Would having this portion of the performance minded work accomplished separately (I.e. do the top now, and the bottom end at some other time) be a recommended approach?

Or is it better to do it all at the same time? (Total rebuild.)

Thank you all.

[djape1977]

my 2 cents:

adding horsepower to engine with less than perfect lower half will dramatically decreaase it's life span.

if i were you, i'd see what's the condition of cylinder walls and do a leak-down test before adding power.

[Daniel]

my 2 cents:

adding horsepower to engine with less than perfect lower half will dramatically decreaase it's life span.

if i were you, i'd see what's the condition of cylinder walls and do a leak-down test before adding power.

I wouldn't agree with this, the gas pedal connected to the drivers foot which is connected to his leg that is wired
way up in his brain telling the engine what to do would control how this extra HP is used. If you drive
the same way most of the time it would have little if no extra stress on the engine. About going bigger
on the cams, sure you will gain some power on a basically stock engine it would be easy to over do the cam size
at this point. I'd go just a bit over stock lift and duration nothing more. After that the next larger Carb up would
give the engine a nice kick in the butt...

[fiatfactory]

.

[djape1977]

fiatfactory, i just love to throw in a comment and await your response
congrats on your experience and will to explain

@Daniel - yes, but in 99% of the cases people increase the power and then trash the hell out of a car. be honest, ain't it fun to accelerate up to redline in second gear in a car with a willing engine?

[Daniel]

@Daniel - yes, but in 99% of the cases people increase the power and then trash the hell out of a car. be honest, ain't it fun to accelerate up to redline in second gear in a car with a willing engine?

YES IT IS!!!!!!!!!!!!!!!!!