HO Head Conversion

Hi

Have a 90 model Renix Dyno result is 170 hp(not at wheels)

What should i expect to gain if i use

91-95 HO Head (Ported and polished)
2000 intake
Bored TB

20-25 Hp maybe?

Do you think it will be noticable? or it would be a hp at very high rpms?

Thanks

You should note a power increase from off-idle up - the HO head breathes better at all stages over the RENIX. I can't quite quantify how much you should gain (there are too many variables still open,) but you're on the right track. However, your 170bhp at the flywheel should just about touch 200bhp at peak, and you'll probably see around 250 pound-feet at peak torque as well (vice whatever the OEM rating for RENIX is - I don't recall offhand.) How much you'll see is going to depend on drivetrain losses - you'll note a lesser increase using an automatic than with a manual, for instance. A lot gets used up in the torque converter and automatic transmission hydraulics.

If i want to buy a new bored TB which size should i go? 62mm or 66 mm keeping in mind of a future Stroker rebuilt.

And should the valve dimensions kept stock or use bıgger valves? (The car will pull from 3250 rpm at least used in races)

Anyone?

Oversize valves are of little benefit due to the shrouding of the combustion chamber....however it is a good idea to use the Mopar stainless steel valves which have a better shape in the head to stem transition and are lighter.

A word of caution.....if you turn the engine above factory redline (5,200 or so) you get into cam harmonics that will fail the timing chain....there is no real need to twist it much tighter since the stock head (even ported) is limited in it's air flow capacity....so tune accordingly...

waht about TB 62 mm or 68 mm?