Question for the car guys

[GtoRA2]

Ok, I just swapped the engine out on my new GTO, the motor from my old GTO was just sitting in storage and it has dished pistons so it runs better on pump gas.

The motor in the car just didnt seem right for a Pontiac 400 performance wise.

Now it feels very good.

My question is, the Carb I am now using is a rochester quadrajet and the power brakes plug into a small vacume outlet on the back, but the line for the brakes is very big, so I have to use a enlargement fitting.

Am I hurting the brakes by doing this? do I need a bigger source of Vacume?

[Ripsnort]

Originally posted by GtoRA2
Ok, I just swapped the engine out on my new GTO, the motor from my old GTO was just sitting in storage and it has dished pistons so it runs better on pump gas.

The motor in the car just didnt seem right for a Pontiac 400 performance wise.

Now it feels very good.

My question is, the Carb I am now using is a rochester quadrajet and the power brakes plug into a small vacume outlet on the back, but the line for the brakes is very big, so I have to use a enlargement fitting.

Am I hurting the brakes by doing this? do I need a bigger source of Vacume?

Not much help here, but I swapped out my "Quadra-bog" with a good Holly 4-popper in high school and never looked back.  Sure, they're a disposible carb, but did you ever try to fine tune the jets a quadrajet?

[GtoRA2]

Lol
 The Quad is ok, the one I have was rebuilt by a really good shop before the owner got killed and it has been really good. Good power and decent gas milage.

I may be fooling with jets soon lol, since this carb was set up for a manual, I am not sure how much this will need to be changed do to the new tranny being an auto.

[lazs2]

Just bought and installed an edelbrock  quadrajet on my big block.  I allready had an edelbrock spreadbore manifold so was limited if I didn't want to replace the manifold.   The new quad is..... new.   all new not rebuilt it is also 850 cfm and has an electric choke.  adjustable mid range but.... it is pricey.   A good double pumper holley is about 350.. this thing is closer to 500.  

It runs great...  I will probly wear it out and in a few years just get a new one.   I don't like rebuilt quadrajets.   They tend to warp.    

as for the vacuumn.... hook up a guage to the port.   they are cheap.   If you are not getting 10-14 at idle (I don't know what your cam is) then you have a problem.   I would not even bother with the port on the carb tho...  I would use one of the vacumn ports in the manifold.
lazs

[GtoRA2]

Thanks Laz!

I will give it a try, it seems to work well now, I found a vacuum leak lol.

The cam is pretty mild. Bigger then the stock 350 HP cam, but not as lumpy as the Ram air3 or 4 Pontiac cams.

I want to change it out actually, I built the motor to spin to 6 grand and the cam loses all its power at 5500.

Man it is really running great now!

[beet1e]

Lazs - As you queried the cam that was in use, can you answer an unrelated question for me?

I have a Golf 2.8i V6, but there is now a new engine available, and this car is to be known in Europe as the R32 – 3.2i. A few years ago, one of those engineering outfits was messing with an experimental 3.2 engine in a Golf – even had nitrous. I read about this experimental car, and they mentioned that two camshafts had been tried. (The Golf V6 has the two banks of cylinders in a 15° V, using a single cylinder block and only a single camshaft)  One camshaft was known as a 266° and the other was a 286°. To what do these angles relate? Apparently one cam gave better performance, but made the engine fussy. The other cam, offering reduced performance was considered better for road use.  Anyway, I am curious to know what those angles mean.

[lazs2]

these are not angles... they are degrees of duration... the duration that the valve stays open.   the longer the duration... the higher potential performance.   there is a lobe seperation angle also but you did not include that.   Your duration figures seem very high so I would guess they are total duration and would be closer to 220-230 degrees at .050" lift.   Often, the exhaust and intake valves will have different durations depending on the efficiency of the respective ports.

basicly... lighter cars with high compression can take the most advantage of higher duration and higher lift cams.   It all has to work together tho and you need a certain CFM level for carb/injector and you need more spark advance and higher octane.  

 higher duration/lift  cams also kill vacumn at idle hence the fudging I did on his vacumn.

I know little or nothing about overhead cam motors but this is all basic stuff.
lazs

[BUG_EAF322]

Beetle i did that with my 1600 vw engine
I put in another camshaft.

it makes ur opening valve time  longer or shorter

It made more HP  got about 60+ hp now
in the low and medium revs

I can stay in front of modern frontwheel drived cars for the first about 100 meters.

[beet1e]

Lazs -

Your duration figures seem very high so I would guess they are total duration and would be closer to 220-230 degrees at .050" lift. Often, the exhaust and intake valves will have different durations depending on the efficiency of the respective ports.

Yes, I am not certain of those numbers, but it was certainly 200+.  Now I know that in an internal combustion engine, there are two rotations in a complete cycle - 720°. Or on average, 180° for each stroke (inlet, compression, ignition, exhaust) But to that we have to add valve overlap - inlet valve begins to open before exhaust valve closes so that outgoing exhaust has effect of helping the intake of mixture for the next stroke... So are we saying that the 266/286° angle would be the total duration that both exhaust and inlet valves are open?  Seems a reasonable figure... (?)

Yep, Lazs - most modern Euro engines have overhead cam (OHC) these days. I can't remember the last time I had an OHV engine (overhead valve) except in the beet1e of course. The important thing to remember when starting from cold is not to rev or put the engine under load until the oil has had time to circulate up to the camshaft and valve gear. People who don't remember this will find they get premature wearing of camshaft and valve guides. The other important thing is to replace the rubber toothed drive belt at the recommended interval, which will be around 40,000-60,000 miles. No need to explain what happens if that breaks... The modern engines like the Golf have some way of achieving variable valve timing according to various factors. Works well. I can pull away from 10mph in third gear without fuss. I've got 6 forward gears.

BUG_EAF - That 1600 seems to be de rigeur for air cooled Beet1es these days. If I had an engine replacement, that would be the one I would get. My bug started out as a 1200, but now has a 1300. It's OK. I had to take a pic for the insurance company, as mine is insured under a Cherished Car policy. I'll attach the pic here - notice anything unusual about it?