34PCT turbo mods pics

[mike thompson]

Boost control only is the correct answer. You get ten points.

[jweir]

that's a wastegate. You can adjust the boost with a fitting that has a check ball and a spring in it. I got one for $20 on e-bay, I'm up to 10psi on my setup. Get a BOV, you'll need it. I found a used one ($20) off of a mitsubishi 2.0 that should work fine.

[miniman82]

Hooray for DSM valves!

[PEPPE]

on a french magazine, thre is a modification for using a 34 with turbo.
it lists:
orings on axle, 250 intake valve, 190 main, 110 air, 55 idle, removed venturi, added a secondary venturi.
they get 138 hp on the dyno with a stock 1600 with E100 cam and uprated springs.
what do you think?

[jweir]

miniman82, do the DSM BOV's limit boost or can you run 10-12psi through them? I just got mine hooked up today and it sure makes a big difference. I dunno how I got by without a BOV for as long as I did. easy install as well, just use the drivers side vacuum tap on a DP manifold. I'll post pics. No BOV sound though, the DSM valve I have is pretty quiet.

[slimesub5]

It's been a while, but I did manage to do a complete installation last year following Mikes brief.....
The motor ran well, pulled much better up the hills fully loaded with camping gear and trailer!!

However, I ended up taking the conversion off and resorting to twin IDF's!!!

The reoccurring problem I had was the engine kept cutting out, one w/e away I must have taken the carb off 12 times to clean the jets!!

The problem appeared to be some sort of "slimey" "plasticy" almost clear deposits blocking the jets, mainly the Main jet. So the engine would just die. Clean it out - ran well for say 20-50 miles then bunged up again.

Now the engine ran fine before the conversion on a single weber, and fine since on the twin carbs. I had and still do have filters in line, no sign of any "sludge" there, nothing in the fuel pump, tried changing both, just seems to form in the carb...

Could it be the fuel getting too hot and the additives dropping out???
ANY ideas, as I would really like to get the Turbo back on.....?

Cheers

[slimesub5]

Anybody??

[sixty5slug]

Wastegate controls boost, BOV keeps the turbo spooled up thus removing chance for turbo backlash which accounts for that turkey gobbling sound.

[CALIvwgeek]

A BOV is only there to prevent the boost from reversing intake flow.
When the throttle closes, the turbo spools slower, so there is a vacuum in front of the turbo (lower pressure more correctly) and if the pressurized air is reversed, it would have more force then the exhaust. The BOV is to prevent that air from going in reverse flow and messing up the turbo in horrid ways. You ONLY need these in blow through applications, draw through (carb, turbo, manifold) style set upts DONT need it.

That's all its there for. BOV, BPV, Pop-off what ever you want to call it same thing.

All that a wastegate does is limit the amount of exhaust flow gets to the turbo so that you can set the PSI to the bad boy.

A BOV does NOTHING other then act as a safety measure for your turbo.

[sideshow]

...The reoccurring problem I had was the engine kept cutting out, one w/e away I must have taken the carb off 12 times to clean the jets!!

The problem appeared to be some sort of "slimey" "plasticy" almost clear deposits blocking the jets, mainly the Main jet. So the engine would just die. Clean it out - ran well for say 20-50 miles then bunged up again.

Strange, a year ago I was fighting a clear jello like wax clogging my idle jet in a Solex 31 (german solex, not the 31 out of Brazil). Couldn't find the source even after changing the pump and cleaning the tank & screen many times.

[cdxanti]

I've read your thread several times now. What size jets are you currently running or what size drill did you use. I seem to loose track of how many mm you have gone up. How much did you take off the choke plate 1/4, 3/8 etc. And you solder shut the two holes furthest from the screw of the ET if i'm correct. And you've put grooves in all the jets basically. Detailed pics of the choke and ET would be appreciated.

[spoonerdtg]

When putting the o-ring on the shaft seal on the fuel pump do you fit it round the plunger seal?

[jweir]

I'll post my response to spoonerdtg here as well.

You'll need to put a groove in the pump shaft for the o-ring (size 008, use viton) to sit in. The groove sits about an inch below the top of the shaft. You want to seal the shaft up from leaking pressurized air past it into the crankcase. the o-ring should make a positive seal between the pump shaft and the plastic piece that holds the shaft into position. The plastic piece is the one that goes between the fuel pump and the case. I used a hacksaw blade held in a vice and put the pump shaft in a drill to make the groove. Make sure the groove is just right, too small of a groove and the o-ring will bind up. too large of a groove and the o-ring will get sloppy and not seal properly. It takes some test fitting and more grinding to get it just right.

[jweir]

Slimesub5, maybe the carb is getting too hot I'm with you on that diagnosis. We run our setups on buggies so the carbs stay a bit cooler than an engine under cover. An intercooler might help your problem? maybe all of the fuel boils off and leaves a residue when you park it with all of that heat trapped under a hood. You didn't say what the engine is sitting in but I'm assuming it's a bus if you've got a trailer and camping gear. Have you ever had it vapor lock?

[spoonerdtg]

Cheers Mr jweir have now done the fuel pump mod