in the last thread we were talking about the pump sprocket...
Your using the small shaft IDI style injection pump with the 12mm head?
I am using a modified diesel MK1 bracket but not the injection pump portion... having to modify the timing belt cover backing plate slightly...no big deal. As for the hb and serp belt setup...i prefer that compared to the v belt. Did you ditch the TDI's timing belt setup all together; the self adjusting tensioner and the deflection pulley as well? Interesting...
Glad to hear you have it on the road... soon soon. Work is beginning on my AWIC setup as well as the head and a few other pics while waiting for the tax$$ to come through...
Joe
In the future (i have an extra MK3 accessory bracket) I'll probably convert the 79 too if i keep it. I already have the alternator though for the mTDI setup, etc. from the MK3 application so I don't have much into it. 
That's gonna be an awesome Rabbit! I'm curiuos though, why are you using a 4bt pump? I thought the Bosch VE would handle this. Aren't they used on the M-B 240 & 300 D/TD's?
Now what I'd really like to see is the electronic VP44 be fitted to a TDI engine with custom CPU programming and I'd be all over that. The VP44 can handle ALOT more injection pressure vs. that of the VE pumps that were used on the TDI motors.
Yes, I am using the Cummins 4bt pump, it is a Bosch VE rotary unit though. Most people doing the mTDI conversion are using non DI specific hybrid pumps. In some cases even, a complete 1.6TD pump turned to the max. in stock form. Others, and a better solution like hillfolk'r is using a hybrid consisting of the IDI TD pump internals and smaller mainshaft with a larger 12mm head.
My setup is a mechanical pump from a DI engine already, so...IMO its better fitted to the engine and is more likely to last longer and handle the injection pressures that the TDI engine demands vs. that of the hybrid pump. Plus, in my experience hearing the hybrid pump on my friends TDI Westy Synchro run vs. when we had the 4bt pump on and installed...it was NIGHT and DAY. Just initially off the bat with the smoothness and sound of the motor but then also with the power of the motor too. His drawback was that it smokes a little much for his liking but in a Vanagon part of the problem there is now his intercooler setup is too small for the fueling he has which is soon to be answered with an AWIC setup. I also have many flow improvements as well to the intake system as well as the head which I'm working on as we speak. So...its def. going to be fun!
On a seperate note... the pumps used on Merc 300D's, etc. that I have seen were all Bosch inlines...though, i've heard of a few that were VE rotary. 4bt's came in two varieties as well... the VE and the bosch inline tooNow what I'd really like to see is the electronic VP44 be fitted to a TDI engine with custom CPU programming and I'd be all over that. The VP44 can handle ALOT more injection pressure vs. that of the VE pumps that were used on the TDI motors.
Joe
Quote from: "RabbitGTDguy"Yes, I am using the Cummins 4bt pump, it is a Bosch VE rotary unit though. Most people doing the mTDI conversion are using non DI specific hybrid pumps. In some cases even, a complete 1.6TD pump turned to the max. in stock form. Others, and a better solution like hillfolk'r is using a hybrid consisting of the IDI TD pump internals and smaller mainshaft with a larger 12mm head.
My setup is a mechanical pump from a DI engine already, so...IMO its better fitted to the engine and is more likely to last longer and handle the injection pressures that the TDI engine demands vs. that of the hybrid pump. Plus, in my experience hearing the hybrid pump on my friends TDI Westy Synchro run vs. when we had the 4bt pump on and installed...it was NIGHT and DAY. Just initially off the bat with the smoothness and sound of the motor but then also with the power of the motor too. His drawback was that it smokes a little much for his liking but in a Vanagon part of the problem there is now his intercooler setup is too small for the fueling he has which is soon to be answered with an AWIC setup. I also have many flow improvements as well to the intake system as well as the head which I'm working on as we speak. So...its def. going to be fun!
On a seperate note... the pumps used on Merc 300D's, etc. that I have seen were all Bosch inlines...though, i've heard of a few that were VE rotary. 4bt's came in two varieties as well... the VE and the bosch inline tooNow what I'd really like to see is the electronic VP44 be fitted to a TDI engine with custom CPU programming and I'd be all over that. The VP44 can handle ALOT more injection pressure vs. that of the VE pumps that were used on the TDI motors.
Joe
Cool, but what are the "cons" to this pump. What kind of shut-down is used and what kind of cold-start assit device (eg; timing adv) does it have?
dont wanna burst yer bubble,but the vp44 is a piece of crap,at least the ones on isb's,,,ive changed a bunch out ,,, theres all kinds of recalls+bullitens and stuff,,,,id like to try an inline,,but may behard to get the revs out of it,,and oiling ,,and ,a few other problems i can see that would have to be dealt with,,,more power potential in a inline vs. rotary shootout,,,but revs can be a problem,,,,i guess u would call it "plunger"float,,tougher springs can eat up cams,,,, iseen some crazy custom pumps somewhere online,like 10-20k!!!!!!!yea jus a big chunk of billittttt,,sweettttt!!!
Its a DI specific pump, plenty of fully and with the gov. swapped over , etc. it makes the TDI run so nice and smooth with PLENTY of power. There may be some merit looking into adjusting the timing advance springs to match closer to the VW rates, but you also have to take in acct. the head/plunger size as well as other things. Considering though that you can get a new 4bt pump for 500 outright new, 450 rebuilt or 250 used... its the simpliest solution IMO to make the mechanical TDI make the most power it can, yet run smoothly and still have the insurances of knowing you have a pump under the hood that is made to handle what your throwing at it.
Joe