Fuel recirculation system elimination

[JasinC19]

Hey guys, I am putting a 90 horse v4 together.

I am trying to put a 1999 intake manifold on a 1979 block.

I noticed that the '79 block does not have the nipples near the cylinders t connect the fuel lines from the intake manifold for the fuel recirculation system that is on the '99.

A friend told me I could plug the check valves on the intake manifold and just advance the timing to help burn the unburned fuel.

I wanted to get feedback from the community about it though.

In '79 they apparently didn't use this system. Can I expect a slightly rougher idle, but it should still work fine though?

Thanks!

 

[flyingscott]

What yr is the actual intake manifold you are trying to put on? A 99 intake should be from a looper motor and 98 was the last yr of the crossflow I believe. You cannot advance the timing just because you want to. Why not just get the correct intake manufold for it.

 

[Tim Frank]

^^^^ +1

 

[JasinC19]

The intake manifold is from a 98, E90TSLEUA. They are both crossflow motors.

I could swap the '79 manifold back on. I am using all the ignition etc from the '98 motor so I wanted to use the intake manifold as well. Since the '98 manifold is already on though, would it hurt to just plug the check valves?

Thanks!

 

[Faztbullet]

Use the 98 transfer covers as the fittings should be on them....

 

[JasinC19]

Hi, got the motor up and running. The engine runs great until i run WOT for a while then the idle is mud and wants to cut out.

When I take cowling off I see blue oil/gas mix dripping out of air cleaner/lower carb area. see pic below.

Could this be because the fuel bleeder system has been elminated? Negative crankcase pressure somehow?

I mean how did the older motors fare with not having a bleeder system??

Other posts have suggested that this could be a float issue in the carb... I will inspect that this week but wanted to understand how older motors dealt with not having some sort of PCV system in place/fuel bleeding system.

Thanks! Motor is sooo close to being done. She screams at WOT!

 

[racerone]

Is the wee hose between the intake manifold and airbox missing ??

 

[JasinC19]

Update: I had previously looped together the bleeder valves on the intake manifold to 'delete' the bleeder system since I did not have the provisions on the block to run the lines to drain them.

I took the carbs off yesterday and found that one of the lines had broken. This may be where the fuel mix was leaking from... (still kinda looked like it was coming from the airbox though)

As faztbullet mentioned though, the transfer covers have the nipples on them. However, there are only two nipples. The other two nipples are on the block. So I tee'd hose together for 2 of the cylinders to one transfer cover and 2 to the other. Hopefully this is acceptable and will work!