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Oil Temperature and Jetting

Posted: Wed Jul 21, 2004 9:50 pm
by speedy57tub
Jake and all,

How much does jets that are too small affect the oil temperature? I currently still have an oil temperature problem (260 degrees :shock: ) and I was going to add an external oil cooler and fan, do away with my oil thermostat bypass, and use the cooler provision I was allocating air from my 911 setup. I feel that the oil cooler setup I have is not up to the job due to possible design drawbacks of my own :cry: (not a complete waste of time since I could always use the setup to heat my interior) :lol: . I just need a little input before I start to dedicate some time this weekend. I want to try all possibilities first. I am depending on all of your experiences. My engine specs are as follows:

Type I 2110-cc (82-mm x 90.5-mm)
New AS41 case
Chromoly I-Beam rods-stock length
My own 911 design (head temp for #2 cylinder is 300 degrees)
Compression ratio of 9.5:1
Dual 44 IDF Webers
12.5 lb. lightened flywheel
30-mm Melling oil pump
Castrol GTX 20-W50 oil
Full-flowed case with HP-1 Fram oil filter
Oil-thermostat bypass valve (opens at 180 degrees)
My own Type IV oil-cooler enclosure design cooled by THe 911 shroud Facet electric fuel pump

Current jetting is 55 idle, 135 mains, 36 Venturies, and 2.00 air correction.

What do you all think? :? Are the main jets ok or too smal and could they be causing my oil temperature problem? I need to get this engine and car going so I can start on my 912 and it's Type IV! :wink:

Posted: Wed Jul 21, 2004 9:55 pm
by MASSIVE TYPE IV
The heads would also be a tad hot if it was lean.. Jet it up a size or two and see what happens.. Jetting sounds good to me, but you are at a weird atmosphere there in Vegas..

Posted: Thu Jul 22, 2004 7:10 am
by speedy57tub
That was my hunch too but I really trust your valuable experience. The car actually ran pretty good until we got blasted with the heat! :oops: I ll try and see what happens.

Posted: Thu Jul 22, 2004 7:15 am
by dstar
With 36 vents and 200 airs, go ahead and make the
jump tp 150 mains. You may have to drill to 155, but 150
will get you close.

Don

Posted: Thu Jul 22, 2004 7:21 am
by MASSIVE TYPE IV
Dstar, the 36 vents really like a 135 in my combos, I would say a 145 is maximum for sea level with that vent... 150-155 will fatten it up like a Boar hog!

Posted: Thu Jul 22, 2004 8:53 am
by dstar
MASSIVE TYPE IV wrote:Dstar, the 36 vents really like a 135 in my combos, I would say a 145 is maximum for sea level with that vent... 150-155 will fatten it up like a Boar hog!
DAMN! I jsut ordered 155 for my Annihilator and I have 36 vents in a Dell 45!!
:-(

I got:

11.3:1 CR
36 vents
175 airs
155 mains
60 idles

Sounds too fat, doesn't it!
:-(

Don

Posted: Thu Jul 22, 2004 8:57 am
by dstar
MASSIVE TYPE IV wrote:Dstar, the 36 vents really like a 135 in my combos, I would say a 145 is maximum for sea level with that vent... 150-155 will fatten it up like a Boar hog!
He said he had 200 airs. Wouldn't that make it closer?
200 is a big number for air, which means LEANer, eh?

Don

Posted: Thu Jul 22, 2004 9:04 am
by Guest
don't mean to hijack the thread or anything, but just want to ask a simple question. where do you get different size vents for the 45 dells? i think i will have to change mine out later.

that's all, thanks.

bj

Posted: Thu Jul 22, 2004 9:05 am
by bj
sorry, forgot to log in.

bj

Posted: Thu Jul 22, 2004 9:19 am
by Kelley
MASSIVE TYPE IV wrote:The heads would also be a tad hot if it was lean.. Jet it up a size or two and see what happens.. Jetting sounds good to me, but you are at a weird atmosphere there in Vegas..
yeah, your altitude above sea level could play a factor in your jetting, Vegas has a average of 2174 feet above sea level. Here in Atlanta we're about 1026 feet, Jake, since you're closer to the mountains than me, you're probably higher than Atlanta, while Don over there in south cakilacky (Columbia, SC ?) is probably lower than 300 feet.

I say this because whenever I've ridden my bike at an altitude above 2000-2500' (the north Georgia mountains) I have running problems directly related to the jetting in my carbs. just a thought I'd share 8)

Posted: Thu Jul 22, 2004 9:30 am
by dstar
Anonymous wrote:don't mean to hijack the thread or anything, but just want to ask a simple question. where do you get different size vents for the 45 dells? i think i will have to change mine out later.

that's all, thanks.

bj
I got mine at CBPerformance. Good price too!

Well, they are supposed to be here today.........we'll see!
I hate UPS..........OK, I won't start on THEM today.....
:mrgreen:

Don

Posted: Thu Jul 22, 2004 9:50 am
by MASSIVE TYPE IV
I'm at 1550 elevation, with an average pressure altitude of 1350.

Posted: Fri Jul 23, 2004 12:51 am
by Wally
MASSIVE TYPE IV wrote:Dstar, the 36 vents really like a 135 in my combos, I would say a 145 is maximum for sea level with that vent... 150-155 will fatten it up like a Boar hog!
Yes, you would think so.

Also in the last VW-Speed, they did a install on the CB performance update kit on 44 IDF's:
The test engine was an 90,5 x 76,4 (1966cc) type 1 with 146,8 Hp at 6580 rpm (dyno tested at the wheels) and 172 Nm torque at 5370 rpm.
Other specs: 297 Pauter cam, 1:10 compression ratio and 040 heads with 40x35,5 valves.

The update kit had amongst other things, new 175 mains and 200 air correction jets.
After 6 (!) tries on the dyno, it proved that 185 main (!!) and 150 air was optimal.
Power rose to 152,3 hp at 6600 and 175 Nm (5310 rpm). Overall power delivery was reported to be smoother.

One note tho: the jets in the CB kit were not all of the same size!!!!

So, you obviously can hardly do without a dyno if you want to properly jet your engine. One size hardly fits all...

Greetings,
Walter