225 upper rpm limit?

The motor just stops making anymore power at about 3200 rpm.

Is that right, or am I missing some upper rpm power.:?

 

Something may not be right then.

Low rpm in the woods it's fine.

But accelerating on the road its not cutting out exactly more like valve float I guess. Just quits pulling.

I have a used HEI in it.

Can the control module maybe cause that.

I have the adjustable vacume advance in it and it's working

Or valve spring's I guess.

Its not gas it doesnt sound or feel like that

I am running 3.73 gears and 32's, it feels like its in overdrive all the time.

Forth is prettly useless about 1000 to 900 rpm on the highway.

So am planning on switching to 4.56's and 33" tires this winter.

So I think that will help with the power band being right and having more umph at the right time.

 

Something is not right there.

According to a quick calculation you should be doing ~2500 RPM at 65MPH


edit: thats 2500 with a 4 speed manual AOD should be around 1700RPM

 

I wounder if my tach is off...

According to the novak cal. something is wrong...

 

I am voting something in the tach.

 

Try unhooking the vacuum advance. The Hei usually advances itself enough with the 225(unless the springs are really strong). My 71 has hei and I run it w/o the advance.

 

I drove it around last night and tried paying real close attention to it.
The tach is good.
THe advance is right on 30, 35.
Runs real smooth once I found the vacume leak.

Its just geared a little to high not really in the torque range.
Which seems wierd based on lots of comments here.

Acts like floating valves around 3500 rpm.

Have to do at least 55 to use 4th gear.

3rd is 2000rpm at about 45 to 50.

 

I'm with you on that one, Patrick... Never found a need to wrap it much tighter. I am curious as to what the max RPM rating is. Per the FSM (stock engine) the max torque (235) comes at 2400 RPM and the max HP (160) comes at 4200 RPM. I never use the OD around town (below 40 MPH), just on the freeway. Not too many "real" hills around here, but when I lived in San Diego and went to Ocotillo Wells I only needed to shift out of OD into 1:1 3rd when I was heading up the last bit of the I-78 to Julian. Now, off-highway, that's a different story...

 

Backwards ...

Horsepower (net) 160@4200
Torque (net) 235@2400

In all realistic cases, power has to peak at higher RPM than torque, because power equals torque times RPM, to within a constant coefficient.

HP = A * torque * RPM

where A is a conversion coefficient.

The only way you can have torque peak higher than power is if you have a very peaky torque curve, that increases with slope greater than A at less than the peak and decreases with slope less than -A after the peak. Not realistic.

<edit> Also, A has to be larger than 1, otherwise torque has to be maximum at 0 RPM. Also not realistic for these engines.

Chris, not correcting you beyond point out the right values. I just thought the question of whether there's any way for your numbers to be real was interesting.

 

Something is weird about the last two posts. timgr's boxed quote is backwards of Chris's post. You both said the same thing...not opposite things.

 

the 225 thrives with open headers, it really comes alive.
at least that has been my experience with it in the dunes
and I run the extreme upper end, so we're talking 4000 rpm +
it's what works for me, regardless of the guys with calculators (no offense intended)
this is a stock 225 with the 2g and no engine mods

 

I am wondering if the exhaust might be plugged or at least heavily restricted in some manner.. Bad or restricted exhaust = Bad or reduced intake. That boils down to reduced RPM and no power..