48 dell trijet jetting

[nicolas]

i have had some floating points on the 019 distributor on my recently built 2276, so i swapped it for a 009 with a compufire and it goes much better in higher rpms. but there seems to be some issues still. i am guessing the jets need to be changed, but i am unsure what direction to go. i am still having trouble to fully accelorate (trottle wide open) over 6000 rpms, but it goes a bit better (less stumbling) when you go more gentle, but the problem still remains over 6000. it seems to 'hold back'

engine specs

82x94
FK8
CR 9
steve tims  stage 2 42x37 valves
5.325 (H beam porsche length) eagle rods
009 32° total advace
Trijets 48 dellortos with 55 idles 180 mains 200 air. 40 vents (maybe 42, can't remember at the moment)


thanks

[ED2.4]

Hi ,
180 mains seems to be large if you have  40 vents ,170 is better,

another thing to considering is the power circuit ,it's  operate above 5000rpm,

have you clean  the power jets located under the bowl float?what's there size?

the fuel press is Okay at high rpm?what's the needle seat  size?

[javabug]

I am down to 155 main jets on my 2110, with similar specs to yours. Pulls clean up to 7k. I was up around 180 at one point, and it did the same thing, laying over around 6k rpm.

I have smaller vents than you.

[nicolas]

Hi ,
180 mains seems to be large if you have  40 vents ,170 is better,

another thing to considering is the power circuit ,it's  operate above 5000rpm,

have you clean  the power jets located under the bowl float?what's there size?

the fuel press is Okay at high rpm?what's the needle seat  size?

yes the power jets are clean. but i haven't got a clue anymore what the size they are. sorry. the needles on the fuel inlet are also good and clean. fuelpressure is handled by a stock pump. but when i accelorate i can't possibly empty the bowls so there lies not the problem. i am thinking of maybe leaning things out a bit as it seems to be an option i was consideing as well.

thanks for the input allready.

[Brandon Sinclair]

Your mains are prob way rich with the tri jets-with 40 vents I run 158's or 160 mains at sea level.  Go leaner and see what happens-the only way to see is put a wideband on it and see what is happening, then give the engine what it wants.

[nicolas]

yes that is the direction i am heading. but what exactly is a wideband. is this a air/fuel meter, if so, yes it would be very helpful, but no, i don't have one and i don't have a fitting on the exhaust to fit one...

[181]

what you need is Porsche 356 points for the 019. The return spring is stiffer then the one on stock points. You can get the correct points from Glenn Ring.

[tonybone]

Hi ,
Just for comparison my 2276 with FK87 and CR 10.5 ran great on 48 dels! I had 42 vents with 200 air correctors, 180 mains and 65 idles.
A baby to drive around town and a hi revving killer on the street/strip. Great carbs ! Reliable and tuneable !
I made sure that fuel pressure maintained 3-3.5psi even at full throttle.
You do sound over a little on mains with the 40 vents ! Did u try the 42 vents at all!

When my motor was new we set her up on a rolling road and kept hitting that 6000 ish brick wall ! Whatever we did with the carbs it just would not rev out ! We pulled the restrictive muffler and bolted on a stinger and wow all hell broke loose ! There was power now right up to what I wanted at 6800rpm. What exhaust are u running ?

Are u seeing black smoke when she loads up at that 6000brick wall ? Which would indicate an over rich condition ! What's the exhaust colour like ! Black and sooty or clean ?
Hope this helps !

[181]

very helpful! I run a 2276 with Steve Tims Stage II, 48DRLAS and 1 5/8 sidewinder...now I consider this exhaust restrictive..I have 40 vents and I would be interested in effect of 42 vents running with 42 mm intake valves.. 

[Torben Alstrup]

181. If you run a FK8ish cam that header/muffler is not more restrictive than what is normally lost with a sidewinder versus a straigh out the back system.
The Stage II heads are good, but not "that" good. 40 venturies are more than enough for 200 hp. Going larger will only weaken the driveability and torque in the lower rpms where the cam is about to come in.
The issue that Nicolas is referring to, could very well be a twin problem. - Fuel level in the bowls AND jet size. If you are also feeding the pump through a stock fuel line I´d say that´s your main problem.
Get that solved first. And then no offense to you, but if you dont know what youre doing, get it on a chassis dyno at an experienced ACVW person, soon, before you destroy something. It´ll be the cheapest hp you´ll ever get. slightly dependable on exhaust and other small variables a set up like that should yield 170 - 175 hp @ approx 56-5800 rpm. so there will actually be no need/idea in reving it past 65-6600 rpm.
T

[nicolas]

well, even if i don't know what i was doing a good dyno session will result in a much better and faster vieuw on what works and what not. so no argue there.

The stock fuel-line was replaced by a 8mm line from the tank to the carbs and seems to hold up well. But again, a good dyno session could confirm or deny this.

but i want to keep indeed the 40 vents and the 'signal' they give at lower rpms. this is by no means a dragrace engine and was never built with that intention.

the muffler may be a issue due to it being a single quietpack, but maybe i should take my stinger with me to DDD and see what happens...

but if someone could bring some smaller jets for DRLA, please feel free to let me know and do so, as a jet is easily changed and will get rid of the black smoke and overrich condition.

thanks for the help, it seems i have learned a bit more today and had some ideas or doubts confirmed. 

[javabug]

With your cam, venturis smaller than 40mm will give an even better signal for street driving. I am running an 86b (not far from your FK8), in probably a lighter car, and went down to 36mm vents. Took away a good amount of low-rpm mushy feeling.

PS. I love reading Torben's posts, and it is very interesting to read his input in this case!

[tonybone]

Nicolas, some good advise coming in here ,
As with what Torben has said , fuel flow to the carbs is essential ! Get a good electric pump up from and regulate the pressure . Get it on the rollers and make sure ur fuel pressure is maintained!
Single quiet pack ...! Hhmmmm remember what I said about hitting a brick wall until I removed the silencer !! Well it was also a single quiet pack !! Take a stinger along and try that as well !
I was also using an 1 3/4 merged header with the 42 vents !

Keep us posted as I would love to hear that you get those deli,s running perfect !

Tony

[nicolas]

all input is again much appreciated, so i will see what i can come up with and indeed come up with some answers regarding mismatched parts and proper tuning, as i feel there is much to gain in that area as well as most of you suggested or confirmed.

a dyno-session is however not for any time soon, but it would be the best route, i know.

and yes Torben has helped me out a few times and your help is appreciated.

[Torben Alstrup]

Thank you.

Did you also convert the tank outlet to 8 mm., or is that stock ?

Of course a restricktive muffler will limit performance. - There are many sgl quiets on the market, so it is not easy to judge on that info alone. But if the power becomes "uneven" it is 90% sure not a muffler problem, as that usually results in the power curve simply flattens out.
If the power is uneven it is most likely a fuel or ignition problem.

T

[nicolas]

thanks again,

so here is what i cam up with during the weekend.
i drove the car to Bitburg and managed a respectable 10l per hundred km journey. no heating up of the oil, cruised without hickups and picked up nicely on the hillier parts of the journey.

so at DDD i did some racing and i took of the aircleaners and belt. the muffler stayed on as no stinger is allowed. and it didn't have any hickups or loss of power on the track. so  think it runs OK on the jets it has now, taken into account that it was pretty hot for European standards and that i did take of the filters (which could cause a over-rich condition in my experience). the muffler didn't cause any significant problems, seems to be a good one, but i haven't had the chance to test without one to really compare.
on the way back i was stuck n traffic for a bit and it didn't heat up with the oilcooler fan on. i was pleased with that. as i feared the worst when we hit the traffic jam.

another reason i will stay with the jets is the fact that there is no easy way to keep hot air out of the engine compartment of the fastback and that has certainly a negative effect on performance and cooling. so i am staying on the safe side for now and i do keep in mind all you have been saying as it probalbly will come in handy when this engine is put in a type1 enginebay.

btw i did a best of 14,61 in a stock weight fastback (can't really figure out how much it weighs..., but an estimate of 2050lbs won't be far of and maybe even on the low side) and i don't know how much hp that is, but it has a huge funfactor that is for sure.

again thanks for helping.

[Zach Gomulka]

My 68 fastback was close to 2200 pounds with me in it as I remember, so your number sounds close.

Do you have it set up as an upright type one engine now, or flat type 3? What car will it be going in go eventually?

[nicolas]

My 68 fastback was close to 2200 pounds with me in it as I remember, so your number sounds close.

Do you have it set up as an upright type one engine now, or flat type 3? What car will it be going in go eventually?

its a type1. the parts i bought about a year ago from Airstuff were used for that. i was going to sell the engine in order to learn a bit more at enginebuilding and to fund the type3 engine. but for now i don't have my type3 case back, so i fitted this one and it was a good test to see if there was anything wrong with it. it seems to be a very good combo and drives very nice. i have found out that a streetcar/type3 needs a type3 engine as the type1 leaves to much hot air in the enginecompartment and cooling isn't ideal as i stated before.
so i'll be forced to find a type1  maybe that will happen, maybe that will take some time. i have been on the lookout for a good latemodel car that could suit my lowbudget project, but nothing has come up so far.

thanks for the number, i found a 2050 lbs weight for notches and 2200 for squares, but i didn't find out if it was with or without gas and driver. anyway the more the better for my HP calculations