My new exhaust

Jak Rizzo · 2004-06-18T20:44:27+00:00

Hi guys, Just fitted up a new system yesterday. Its a fully merged S & S 1.58 inch header , with the collector cut back to a full 2 inches, then it goes into a fully merged 2.5 inch pipe into a 2.5 inch straight through muffler. It replaces my 1.5 inch system which didn't have a merged collector, went into a 2 inch pipe & into a 2 inch muffler. Seat of the pants so far , with a passenger, it feels as though the motor has really been woken up, it wheel spins in 1st, 2nd & chirps in third & thats in the dry. I'll try to get onto the dyno early this week as this will tell the real story. I also think that I'm going to have to get some smaller airs for the Dells, as I think with the bigger system it will leaning out more. Next will be some headwork to the stock port 040 heads to see if that will make any difference. regards Jak

boof2332 Custom Title Time!

1,210 posts · joined May 2004 · 28 Jun 2004, 1:15 am

#193850

Hey Jak,

Did you ever run 1.4 with that cam???

If it gives poor performance on a fk10 with 1.25's then You would think the same with the fk8, only because they were designed to run only with the 1.4 or 1.5...
Still good power espcially with valve size and running lean.
Just wondering what could happen if the recommended rockers were used...from the fk10 comparision I saw.. from 3500-6500 could experience a pretty noticable bump. My 1.4's are new...throw them on race around the block and them put them back in the wrapping...see what happens.

Matt

[Edited on 27-6-2004 by boof2332]

Jak Rizzo Insano Dub Head

837 posts · joined Apr 2004 · 28 Jun 2004, 5:44 am

#193854

Yeh Mat , we did run cheap crap 1.4's on the 2.1 for a while but they kept falling apart. When I rebuilt it we just put some 1.25's on for reliability more than anything. It's been perfect ever since.
The 2.1 still has some more tuning to go & can also have a bigger pipe & muffler off the 1.5 header like mine, so theres more in it.
regards
Jak

gayanne Officially Full-On Dubber

307 posts · joined May 2004 · 28 Jun 2004, 8:31 am

#193884

Jak Rizzo wrote:Seat of the pants Doug it feels equally stronger all over, but the dyno readout says otherwise.
Once I prevent it from being so lean up top there should be some more power in it as well as well as keeping it safe at high revs.
I'll go back again next week & keep those who are interested posted.
I'm also saving my coins for some 42x37 044 heads from CB. They will replace my 40x35 040's & I'll raise the compression from 9 to 10. I've been practicing porting heads with some 40x35 044's that are going on a 1641cc that I'm currently building so I'll port my new heads myself.
When I built my mates 2110cc I set the comp at 10.1 & thats with 42x37 044's with massive ports & it's running very well staying very cool on the track & the street. he also got 106.8hp @ the wheels with more tuning with jetting to come.
So with my stock port heads I feel there is much more to go with my motor yet, especially once I get the air fuel ratio right.
regards
Jak

TextHello Jako,The motor is starting to come together,breathing is the key for this motor and the heads will make alot of difference just be carefull of cam sizes some times bigger is not better and this why some dont breath properly and they go backwards.It wouldnt hurt to maybe when receiving new heads to look into porting them a little more,just something to think about.JVLRacing

Craig Torrens 6 times Australian, 7 times State Hillclimb Class Champion

8,040 posts · joined Jan 2003 · 28 Jun 2004, 8:48 am

#193892

Jak Rizzo wrote:Yeh Mat , we did run cheap crap 1.4's on the 2.1 for a while but they kept falling apart. When I rebuilt it we just put some 1.25's on for reliability more than anything. It's been perfect ever since.

Jak

Did you notice any power difference (gain/loss) by changing the rockers?

Jak Rizzo Insano Dub Head

837 posts · joined Apr 2004 · 28 Jun 2004, 8:54 am

#193894

Unfortunantly Craig I didn't get to do a back to back test, as I changed the cam, compression , rockers & carbies all in one go. Power went from 88hp @ the wheels to the 106.8hp @ the wheels.
I read on the Shop Talk Forums that some of the guys thought that there was more tourqe with using 1.25's on the K & FK series engle cams, but then they also said that using the 1.4's made the engine feel a little "peppier" so it may be a case of 6 ways or half a dozen, ?
Jak

boof2332 Custom Title Time!

1,210 posts · joined May 2004 · 28 Jun 2004, 12:53 pm

#193969

Craig,
what I was talking to Jak about related to a comparison that i had with a fk10 that they used 1.25's on to see if it made power sooner ...it was dissapointing. The engle fk series was designed to perform a specific way with a specific rocker...I too thought of possibly doing it instead of changing my fk10 ..glad i didnt.

matt