CarFreek

I have had 3 B18's, 2 a1's and a 95 b1. (All OBD1)
They all say PR4Y on the back of the head, But the other side has cast,
On the 90 PR4-1 the 92 PR4-2 and on 95 PR4-4. What is the difference?
And why is the 90-91 B18 redline lower?

CarFreek

Anyone??

Maybe I'll post this one on the all-motor forum?

Dogginator

If it is like the VTEC heads, the -# doesn't really mean anything. For example, PR3-2, etc.

turbociv910

lower redline,

obo

CarFreek

I was thinking that it was in reference to the parts that go with the head.
Like the PR4-1 was the 90-91 with the 57mm TB, The older distributor and the 4-1 exhaust manifold .
The PR4-2 was the 92-93 with the 60mm TB, The newer distributor and the 4-2 exhaust manifold.
And the PR4-4 was the OBD1 b1 with the newer intake manifold.
But I wasn't sure if their was anything Else different.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turbociv910 &raquo;</TD></TR><TR><TD CLASS="quote">lower redline,

obo</TD></TR></TABLE>

obo??

CarFreek

The 95 PR4-4 I had in the car for a bit seemed to make better power than the stock motor. (the PR4-2)
And the 90 PR4-1 than I have in their now seems to make less than the stock motor and seems to weez up top.
And all 3 motors where run with all the parts from my stock motor, just the head and block switched out.

PACT man

The 90-91 does have only 130hp compared to the 92-93 with 140hp and the 94+ with 142hp.

CarFreek

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PACT man &raquo;</TD></TR><TR><TD CLASS="quote">The 90-91 does have only 130hp compared to the 92-93 with 140hp and the 94+ with 142hp.</TD></TR></TABLE>

The 90-91 made 130 hp because of the 57mm TB the 4-1 exhaust manifold with the 1 tube mid pipe and the older distributor.
On all 3 motors I used the same parts.
The 92+ (60mm) TB and intake manifold, The 92 distributor, and a 4-2-1 DC header for a 92.
And all 3 motors where run off the same ECU.
And unless im mistaken the last 2hp didn't show up till the switch to OBD2 in 96.

PACT man

The 90-91 has a different exhaust cam than the 92-01's along with the exhaust manifold and the ECU(90-91 being OBD-0) are the reasons for the 10 hp. I don't know anything about the TB being different. The 94+ had the different intake manifold being the reasons for the 2hp.

CarFreek

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PACT man &raquo;</TD></TR><TR><TD CLASS="quote">The 90-91 has a different exhaust cam than the 92-01's </TD></TR></TABLE>

That I didn't know thanks.
Could i swap out the exhaust cam from oy 92 head?

PACT man

Yes, the cam just has a slight lobe height difference, but it is a difference nontheless whether it's noticeable or not.

CarFreek

That's probably why it seems to weez up top.
Do you know why the 90-91 had a lower redlind than the 92+??