Spent half my saturday hammering the ovalised ends of the rear bank of 24valve 164 headers round - had to pie cut and weld them to get them back down to a 42mm tube - the expanded section for the oval port is actually up around 47mm or so diameter when you make it round again.
Mats wrote:
la_strega_nera wrote: It's *got* to be possible to make 100hp/l with a 12v v6 under 7500rpm, heck the combustion chamber is better than the Nord and there are ppeople screwing 105hp/l out of them with their shitty ports and screwy combustion chamber....
Isn't the problem really the limitations in the vavletrain? You can't use the cams you want behause of those fragile rockers/pushrod guides?
What really annoys me is that people don't seem to be getting any power out of the 24v engines either...
Yeah, the early rockers are a bit crook, but if you use the later 164 rockers they're stronger - and there's some black magic with the exhaust cam profile to get them to live properly - so for the cams I'd just buy a set off Rich Jemison in the states, he's already done the hard work there...
And of course you need to locate the rockers properly - get rid of the stupid spring setup and machine up some sleeves.
I have noticed the lack of real power seeming to be made by (most of) the 24v motors - all seems to be well under 100hp/l and people just interested in making them bigger... I'm itching to get my hands on a set of 24v heads and send them to a certian porter I know who seems to be able to make just about anything flow well - would be very interested to compare them to some of the other stuff around (BEAMS toyotas etc).
From what I've heard even from Beninca, he said don't touch the heads. Ports are too big as is. JimK has flow figures of 24v heads. I think even he just cleaned it up without extensive work.
Also, why can't you get 100bhp/liter from a 24V? Beninca built a single throttle GTV6 3.0 24V has 278 whp at 7800 rpm.
I got the RJR 590/82 cams in my 75 and RJR 570/XXX in my 155 V6.
From what I've heard even from Beninca, he said don't touch the heads. Ports are too big as is. JimK has flow figures of 24v heads. I think even he just cleaned it up without extensive work.
Also, why can't you get 100bhp/liter from a 24V? Beninca built a single throttle GTV6 3.0 24V has 278 whp at 7800 rpm.
I got the RJR 590/82 cams in my 75 and RJR 570/XXX in my 155 V6.
I don't think that there would need to be alot of material removal, just tidying up around the seats/bowl/short turn - seems to be standard for modern multivalve stuff - reshaping rather than simply boring the bejesus out of them like you have to do with the old 8v single plug motors.
I'm not saying you can't make 100hp/l (hell, must be able to make close to 150hp/l out of them if you can keep the cam belts on), I'm just saying it doesn't seem like anyone is really trying - but i'd love to see how far it could be pushed... only problem is all the classes I'm looking at would have to run 12v to be legal - beats me how there are guys running 24valvers under the CAMS Group 2B rules.
How do you find the RJR cams in the 75 and 155? My only concern with camming the 164 up a bit later on down the track is it's a relatively heavy car for a 3l...
Funny, we were discussing the largeness of the 24v ports in the garage just the other day.
Would be interesting to try some simulations on that engine. If you compare it to what the HFV6 units in the Saabs looks like the Alfa unit has HUGE plenum and runners.
Mats Strandberg -Scuderia Rosso- Now burned to the ground... -onemanracing.com- -Strandberg.photography-
GTV 2000 -77 - Died in the fire.
155 V6 Sport -96 - Sold!
Compared to other cars of its size, the 164 is not that heavy. Just go with lighter wheels and maybe put in some lightweight reclining seats, smaller single muffler (helmholtz type which doesn't drone), throw away the stupid heavy wing on the boot lid, smaller battery, and voila I think you can shed 70 kilos.
From what I have seen, actual cam data on the QV cam lobes which RJ sent me, they're extremely mild Especially on the exhaust side.
Anyway the 164 does provide a nice combo between fun, comfort and speed. So I don't think camming it would be a bad idea. And you've got to get the projector lights, it really makes the car look more modern.
BTW speaking of cams, I'm still using the cam marks on the cap and cams. However RJ and JK told me that the marks may not be reliable. Think about it, when I ordered the cams RJ told me to make my mind up about lobe center separation. And the difference was just a few degrees. Now I asked JK about setting up cams and he said even his Catcams' mark were about 12 crank degrees off from where it was specified to be. So I guess I've no choice but to get the gauge setup to find TDC and X mm lift @ X degrees to setup the cams.
Yeah, the S/QV cams are pretty mild, and I spose that it is pretty light for it's size - it's still a big car to thread up a narrow twisty road when chasing a 156GTA and 916GTV6... but I spose that's what my 105 is for
I know i could strip a tonne of weight out of a 164, but i'm not sure that''s what this car is really about... and i may be adding a little weight in the exhaust...
Basically I'm using a F360 Flapper valve and tips to set up a bypass system on the rear muffler - 3800rpm and it'll open up and run front resonator/middle resonator no rear muffler - vac operated, electronically switched just like a ferrari - the thing is too civilised in auto suspension mode to just put a loud exhaust on it...
Where did you by the bypass valve from and for how much? I've been looking around, can't find any for a good price. Most of the actuators which move those valves, sold by aftermarket companies, are boost operated while I need the exact opposite.
I put up a wanted ad on F-chat, and stalked them on ebay - found one guy who had 6 complete sets of 360 exhausts in stock, $500 for the muffler and the two tips/actuators, asked him if he'd split it - yeah, $400 for one, or both tip sets. "Yeah, well if I'm going to split a set up so I can't sell it..." Dickhead - clearly he's going to be sitting on his stock for a while,
Finally PM'd a guy on ebay who had a full exhaust with a $100 starting bid that no-one bid on, offered him a sensible amount for just the tip sections and viola. Considering I'm going to use the chrome tips too, it works out relatively cheaply and I have a backup set of tips/actuator too. Wound up being $300US for both sides (plus postage) - and when you consider a half decent single tip is like 60AUD, it's not too bad.
Ben good to have you back. Mats is right , there are no wild 3.0l 24v hp figures on this forum. From my side I had dreams of high wheel hp figures but I am only sitting at 208hp on the wheels (same as e36M3). Only mods is intake cam ,big runners,plennum,and aftermarket ecu. I am at 6000ft above sea level.
Would be nice for you to pioneer some work on the 24v.
Unfortunately I've only got a 12v 164, and the classes I want to run in mean i'd have to stay 12v in a GTV6...
I noticed JJ is claiming 330rwhp from his 3.7 at sea level at 12:1 compression and race fuel - depending on what kind of dyno that was on, it could be about 390fwhp (not bad, 107hp/l is still not that impressive for "full race" multivalve with ITBs and cubic money), or it could be about 350fwhp... which is lame.
either way, new toys arrived this morning:
tips fit nicely
Ben, I saw this week 301 on the wheels of a 147 3.7 road car - standard fuel(Glenwood) full house on the same dyno mine made 208rwp so yeah its definately possible at sea level.
Need a soundclip once your new toys are fitted.
I reckon that would be pretty healthy Kev
Had to build a new mid section for the exhaust on the 164 - the one part I thought was fine was pooched when I pulled it off.
So... Front section, plus Cat/resonator thingy.
Rear section - Muffler and bypass.
And the tips in position:
I haven't hooked up the vac lines or the control box yet, but they're a piece of cake. Sounds pretty good with the bypass open though!
So is the bypass pipe full 2.5" or is it cut in half and welded to the muffler? Looks like the muffler was cut to accommodate the bypass pipe.
Straight part of Bypass pipe is 2.5" - muffler cut to clear it - rest of bypass is 2.25"
The bends exiting the muffler are the original ferrari stainless bends, the muffler is stainless, but the bypass tube and the rest of the pipework is mild steel.
