The BIG VK Manifold Question!

[oshi16]

Hey Guys,

I'm calling in some help on this one. This question will not be for the feint hearted I don't think.

I have an 85' VK Commo with the black 202 carby motor. I've done an electronic dizzy conversion; and a Weber 34ADM Conversion (all running sweet). I've replaced the entire cooling system and various other bits and pieces. Also did a gasket replacement job from the head gasket and above. (push rod, exhaust...etc....)

The problem I have is this: My Vk is overheating in warmer conditions and increases more under load over 80KM/h. The engine runs sweet, the cooling system is doing its job and the timing/tuning is good. I've wrestled with this problem for over a month trying various different things and I think I may know what the answer is, but I need your opinions.

(this info is only my opinion, please correct me if I'm wrong =D ) The connection between the Intake and Exhaust manifold on the standard stock EST VK connects with two open ports (this is where the intake sits on the exhaust). One of the ports (left one/closer to the front of the car) has a heat valve/butterfly valve that opens and closes depending on engine conditions, and is controlled by the EGR; and/or the other emission crap. And I'm under the impression that this is a normal setup. The smaller (right) port stays open to allow an opening between the intake and exhaust (due to blockage possibilities or something...this actually confuses the hell out of me...why the hell is it there!?); and the bigger right one opens when the engine is cold and shuts when the engine is hot...I think.

My Point is this; I have removed the butterfly valve (melted it out with a welder, leaving a bodge open hole spacer so it can sit evenly) in conjunction with the EGR equipment (that all seized up). I had no idea what the ports were at the time (this was a few months back when I did the gasket replacement job) and this may be causing my problem. My thoughts are that the open ports are supplying Exhaust Gas Recirculation (EGR) Constantly. Which in turn increases the Engine Temp and causes an odd rough idle after it has warmed up.


Ok so if this is the problem...which I hope it is...so I've finally nailed it this time! But if it is, how would I get around it? I have a brand new set of Pacemaker Extractors which I'm going to chuck on soon; which leads me to another question...how the hell do I fit the extractors with a stock intake? or do I need to get an after market type?

Sorry I know I've bombarded you all with many questions; I really don't want to, but I'm at my wits end! As much as I know about cars (vk's especially) there is still so many basic things I don't know.

Basically my questions are:

1. What are the lower intake ports that connect to the Exhaust Manifold...and will they cause a problem being constantly open?
2. How do I go about fitting extractors with a stock Intake?

Thanks to you all! Any reply will be greatly appreciated!!!!!!!!!!!! =D

Have a great weekend!

 

[dags061]

I have a Vh 202 with Holley and Headers. I cut the lower section of the inlet manifold away so that the headers would fit. No connection between inlet, exhaust.I use an adapter plate with the holley and it goes well after lots of adjustment.I stuck an M20 behind it and it goes lots better.

 

[oshi16]

Ah ok Mad! How did ya block the lower section of the intake valve up? And yeah your VH sounds awesome!

 

[vkberlina]

How did you set your timing?

Scott

 

[dags061]

The Exhaust and inlet manifold are connected, bolted together that is. The lower part of the intake manifold is independent of the upper part,Exhauast gases go into the lower part of the intake maninifold to warm it up a bit so that it would run better when cold.I cut away the lower section with a grinder and fitted headers to the motor. The headers are not connected to the inlet manifold.I have been told that it sounds like a V8 as the headers are 3 times 2 into one so the note sounds like it has a cam but its stock. The 2 1/4" system with muffler only makes the old girl sound sweet. It is no rocket ship and does me fine.Being 50 my hooning days are over.

 

[oshi16]

Hey again Guys,

I timed it by ear Scott. Pretty much what sounded and ran the sweetest after a few weeks of changes. I changed it countless times trying to find the sweet spot; and the way it's running now, it seems to be it...except for the higher temps. I had a squis to see if I could get a timing light of it; which stumps me; how the heck can I a straight shot down on the H-Balencer if there Pully is in the way? Is there a decent way to static time it? or another method of getting a timing device hooked up? Thanks man!

Cheers for the info Dags, I didn't realise it was an indepentent opening..well that rules out that option I think. Oh a side note, you're making me jealous of your VH, I'm pretty much the same, I don't need or want a rocket (if I did I'd chuck in a 5.7) and far past my hooning days...as short as they were. I guess once I started taking pride in fixing and modding the car, I really don't want to stuff it up or crash the girl. I want to drive and enjoy it! There really is something magic about the old commo's. Thanks for the replies; they help a lot!

Thanks heaps guys!

Brendan

 

[Not_An_Abba_Fan]

The bottom of the intake where it joins the exhaust is not open to the inlet anyway, so it can't suck air.

The extractors just bolt on, you may have to trim a bit off the intake manifold where it goes over the studs to make the extractors fit between the intake ports.

Your timing is most likely out if you haven't put a light on it. The "sweet spot" by ear is usually too far advanced.

 

[dags061]

I bought a decent battery connected timing light and found that the timing was way to far advanced.Runs heaps better but still uses much to much fuel for a 202.

 

[codfishface]

For what it's worth now you have solved your problem,

I had a similar black 202 to yours. HEI ignition, Worked EFI head, EST & EGR goneski.
Plus extractors and triple SU carbies (so no OEM manifolds). Twin thermos. High state of tune.

I was running advanced timing 14-15 degrees and was always running hot.
I solved my problem by running a 72 degree thermostat and always carrying a stubby 9/16 spanner in the glove box.
Road-side timing adjustment in summer was the norm.

Before the SU's, I had a remanufactured Varijet and reasonable economy. With the SU's, insane throttle response and even better economy.
What's the condition of your Webber? There's alot of pollution gear on the ones that I have seen and plenty of places for vac leaks.
Got a vacuum gauge? It's your best friend when it comes to tuning.

 

[oshi16]

Ah ok sweet as! thanks for the tip 'Not An' Abba fan. I'll see what I can do on the weekend in regards to the dizzy. Any idea how I could actually set up a timing light on this rig; I've got one, but with the top pully for the AC and Air Pump/injector system (which I'll scrap when I put the headers on) there is no way (that I see) to get a direct line of sight? Any ideas?

And thanks for the comment Cod; that gives me a bit more piece of mind...but it also makes me a little depressed that I don't have a beast like that, haha! As for the vac gauge; I do have one but the hose that goes onto the vac tree has snapped recently; so I plugged the hole and left it disconnected it; I don't really miss it to be honest. I thought of vac leaks too, and I've looked/heard around for em for a while now, I actually solved a couple. But was a while ago; and I had the Weber on when I had the gauge working; it seemed to be running at a 'normal' vacuum to how the engine ought to behave. It's an old Weber of an XE, in a reasonable used condition, can't see anything wrong with it after a few touch ups I made after I got it. I've got a rebuild kit for it on the ready, but I don't have the time to do it as of yet. This car's my daily and I drive a minimum of 2 hours each day; so I can't really risk screwing with it too much just yet.

Cheers for all of the input guys! I'll have a fiddle with the Dizzy again on Sunday, I'll go in under the assumption that I have it set too far advanced and see what I can get out of it.

Brendan