Where to get a 38/38 Weber from?

[MessyHonda]

I thought it was for velocity since one valve open would provide move vacuum for that valve and help pull in the air/fuel.

yup that is what i heard.

[Bad Bunny]

Oh I see, I did a bit more research. So the tri flow cam opens the valves in progression drawing fuel across the chamber at higher velocities, thereby pulling in the second charge faster which, according to the site gives the equivalent to the secondaries opening in a carb. Also, the engine gets better vacuum at idle , less overlap, and throttle response increased. This profile is highly recommended vs a standard... ??

Cygnus: The colt site recommends the stage 1 with FI and the stage 2 for carbs, did you experience any problems running the stage 1 with carbs? I don't want the idle issues associated with a 280.

[cygnus x-1]

I thought it was for velocity since one valve open would provide move vacuum for that valve and help pull in the air/fuel.

Actually yes. That's why I said "... or something like that."

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[cygnus x-1]

Oh I see, I did a bit more research. So the tri flow cam opens the valves in progression drawing fuel across the chamber at higher velocities, thereby pulling in the second charge faster which, according to the site gives the equivalent to the secondaries opening in a carb. Also, the engine gets better vacuum at idle , less overlap, and throttle response increased. This profile is highly recommended vs a standard... ??

Cygnus: The colt site recommends the stage 1 with FI and the stage 2 for carbs, did you experience any problems running the stage 1 with carbs? I don't want the idle issues associated with a 280.

Yeah, idle. For whatever reason I've never been able to run the idle much below 1000 RPM or so, even when it was still stock. It just always seemed really grumpy with the idle set low. But to answer the question, no. The idle is smooth and not lopey like higher duration cams. The vacuum will be lower than stock but not hugely so. I was getting like 20-21in. at 1000RPM. Stage 1 is fine for carb or FI. The reason they don't recommend FI with the bigger cams is because the vacuum is too low and the computer gets confused. If you have some sort of aftermarket engine management you can tune it to compensate to an extent. But for really radical cams you have to use a fuel management scheme that's based on throttle position instead of vacuum.

Now I will say, that it was actually possible to get the engine to idle really low with the Weber, down around 500RPM or so. But it wouldn't be remotely driveable that way. I the idle set at 1000RPM with all accessories off. That way it wouldn't drop too low when all the lights were turned on. Remember that you don't have an idle compensation valve with the Weber setup.

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[Bad Bunny]

Cygnus:
You should sell me your carb setup: the 38, adapter plate, air filter etc. I mean, it's just going to waste sitting around doing nothing. Come one!! I'll even give you $350 for it!

[cygnus x-1]

Cygnus:
You should sell me your carb setup: the 38, adapter plate, air filter etc. I mean, it's just going to waste sitting around doing nothing. Come one!! I'll even give you $350 for it!

Let me think about it.

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[Bad Bunny]

Okay but think fast! Otherwise I have a new one lined up that I will buy tomorrow.

Cheers.

[A20A1]

low idle with large ovelap cam = lots of fuel and timing.

large overlap cam with trick vaccum reservoir = more stable vacuum
lighter springs on vaccum diaphragms = less vaccum needed to operate them
Vaccum valves that run accessories off of exhaust vaccum = no need to worry about hooking up accessories to intake manifold vaccum.
They also have mechanical and electric vacuum pumps.

I had a medium or large cam and I would get 10 inches to 12 inches. @ 1000 rpm. But idle would fluctuate sometimes down to 800. once the exhaust and engine warms up it ran really smooth.

[cygnus x-1]

I can't do it. Can't sell it yet. I'm curious though, roughly how much is the new one? Have you looked on ebay at all?

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[Bad Bunny]

Yeah, nothing on ebay right now and I'm eager. I'm going to be paying 479 (before tax, shipping, duty, etc.) for the 38 with a kit. I'm in Canada so it just sucks that I'm going to have to pay all of that duty and shipping. Oh well. Thanks anyway.

[Bad Bunny]

Does anyone have any thoughts on the power gains I might see with the setup I am proposing? That was the 38 weber, 272 cam, and header to cat-back exhaust? Just speculating.

Also what fuel pressure regulator would you guys recommmend using? IIRC the weber likes 3 psi?

[cygnus x-1]

Does anyone have any thoughts on the power gains I might see with the setup I am proposing? That was the 38 weber, 272 cam, and header to cat-back exhaust? Just speculating.

Also what fuel pressure regulator would you guys recommmend using? IIRC the weber likes 3 psi?

My SWAG would be 130-135HP at the crank. And that really is a SWAG.

Don't worry about a pressure regulator for the time being. Just connect it up stock and see how it works. Or first get a pressure gauge and see what it measures at before spending money on a regulator.

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[Bad Bunny]

ANOTHER question. Header related.

I'm thinking I'm going to go with the 2" header. I already have a 2.25" cat-back exhaust system and the stock cat is still in there. What should I do with the cat? Should I get a high flow or perhaps keeping the stock will provide some necessary back pressure for lower rpm torque. If this is the case, is the header even necessary. Thoughts? Thanks.

[A20A1]

no stock cat.
https://www.3geez.com/forum/showthread.php?t=352

when you say 2" header you mean 2" collector right.

because 2" primaries is too big, 2" collector is great.


The recent explanations I've been reading about moving the torque band around has to do with velocity... thats it.

Torque at low RPMS with small diameter pipe comes quickly because pressure raises quicker and you gain velocity.
Now for larger pipes you need to increase the flow of the motor to increase the pressure in the pipe so you raise the RPM which increases the exhaust flow, so it takes a higher RPM to reach high velocities inside the pipe.

The velocity at which the exhaust gas should be traveling is about 240-300 feet per second


so in reality after reading that link I gave you you should get a better understanding that it's not really backpressure per say but velocity that you're trying to achieve and that for the "y" CFM of your motor, you'll reach "240-300 feet per second" velocity at "x" RPM with "z" pipe diameter.

Still there is much to learn.

And if we had a stock setup that didn't include of the stock cat and muffler and ran just the 1.75" stock system from the header back I'm sure you'd see some low-mid end gains.

[Bad Bunny]

You guys are amazing! The header is a 2" collector with 1.5" primaries.

I ordered the 38 and adaptor! It's in the mail and I should be getting it next week sometime

I'm sure there will be many more questions

[cygnus x-1]

Exactly what A20A1 said. It's not backpressure you want but velocity. The high velocity gas traveling through the pipe has it's own inertia so that when it's not being "pushed" from the header side, it tries to keep going from it's own momentum and "pulls" out of the manifold. It's similar to the water hammer effect in plumbing.

As far as I know all the after market headers available have a 2" collector, so you're pretty much stuck with that unless you want to have it modified.

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[Bad Bunny]

Now regarding timing. I've read I want a 3 degree advance on the cam, what about the distributor? Is the A20A1 an interference engine?

Also, pertaining to the header: I talked to a muffler shop this weekend and was told by the owner that Pacesetter can be a very problematic header to install and can prove difficult after the install, due to the "poor qaulity." of it. Anyone have any comments on the header by Pacesetter? And does anyone else make a header for our cars?

[MessyHonda]

Now regarding timing. I've read I want a 3 degree advance on the cam, what about the distributor? Is the A20A1 an interference engine?

Also, pertaining to the header: I talked to a muffler shop this weekend and was told by the owner that Pacesetter can be a very problematic header to install and can prove difficult after the install, due to the "poor qaulity." of it. Anyone have any comments on the header by Pacesetter? And does anyone else make a header for our cars?

yeah the pacesetter is not the best header....other companies made header for our car like DC and SS. but thoes have been discontinued and even if you found out you would still have to pay alot since demand is high....i have a pacesetter header....some problems people have is that the downpipe hits the front crossmemeber. so you might have to grind some of it off.

[Silent_Hill]

picture of an installed weber please?

[cygnus x-1]

Now regarding timing. I've read I want a 3 degree advance on the cam, what about the distributor? Is the A20A1 an interference engine?

It supposedly is an interference engine but I'm not aware of anyone actually having a piston hit a valve, even when blowing a timing belt.

If you have an adjustable cam gear you can advance the cam timing to lower the power band. You would then have to reset the distributor to maintain the ignition timing.

Pics of my Weber 38:
http://bluegreenlabs.com/Prelude/Eng...eber_38-38.jpg
http://bluegreenlabs.com/Prelude/Eng...ineBayNew1.jpg
http://bluegreenlabs.com/Prelude/Eng...ineBayNew2.jpg


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[A20A1]

My cable used to use a connection like that but on the third run at track it completely slipped out and I idled my way to the finish.

I since midified the stock cable linkage to fit onto the weber, not more slips and a nicer pull/feel to the pedal.

[Bad Bunny]

It supposedly is an interference engine but I'm not aware of anyone actually having a piston hit a valve, even when blowing a timing belt.

If you have an adjustable cam gear you can advance the cam timing to lower the power band. You would then have to reset the distributor to maintain the ignition timing.

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So after installing the cam gear I will reset the distributor timing to 15btdc. How much will the cam gear throw it off? Will the car run without detonating with the cam gear installed and the distributor timing not yet adjusted?

I'm tempted to rotated the crank by hand when the timing belt has been removed to see if there is any contact.

And the Weber should be here soon! I'll try and post pics

[cygnus x-1]

So after installing the cam gear I will reset the distributor timing to 15btdc. How much will the cam gear throw it off? Will the car run without detonating with the cam gear installed and the distributor timing not yet adjusted?

I'm tempted to rotated the crank by hand when the timing belt has been removed to see if there is any contact.

And the Weber should be here soon! I'll try and post pics

The cam gear changes the cam position in relation to crank. And the distributor is connected to the cam so the distributor will be off by however much the cam gear changes it. You'll need to re-adjust the ignition timing when you install the gear and anytime you change the setting on the gear. But it's really easy to do.

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[Bad Bunny]

Where is the best place to by cam gear? I'll check the classifieds section at lunch.

Header has been bought from Little xOx, S&S 4-1 . Cam will be coming out this weekend and sent to Colt Cams for a Stage 1.

Still waiting for the 38/38 to arrive...

[cygnus x-1]

There was a cam gear group buy here recently. Send a PM to "nswst8". He organized the whole thing and I'm pretty sure he still has a few left. Check the sticky threads in the Performance section here too.

Cool, you got an S&S! I have one too that has been sitting at the coating place to be ceramic coated for the last several months. Supposedly the guy's dad has been having major health issues so he's been really slow in getting the thing done. Hope to have it back pretty soon though.

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