'79 Rabbit L TDI

[Rabbit on Roids]

ok, so your idea of putting the oil squirters in your 1.5 block.. good luck. and that cracked block, i would have just put your internals in a 1.6 block under a 1.6 head. 1.5 blocks are garbage and way too weak. you were going in the right direction with the TD motor. jb weld might work for a little while, but if you throw any boost to that motor at all, the crack is probably gonna open right back up, maybe bigger. this is one of those things i would not skimp on or (profanity removed by mod). i may not have much room to talk since i rebuilt my last engine for (including the cost of the engine)$17.85, but hey, its the best runner ive had so far. but yea, its way easier to do things right the first time, rather than half ass them once then pull them out later to fix it again.

[drrtybyl]

ok, so your idea of putting the oil squirters in your 1.5 block.. good luck. and that cracked block, i would have just put your internals in a 1.6 block under a 1.6 head. 1.5 blocks are garbage and way too weak.

So basically what you're saying is to upgrade to the 1.6.

It looks like you're running 18psi on a 1.5 block per your sig  :?:

[blkboostedtruck]

rabbit on roids is right! a turbo motor pressurizes the crank case and with that crack and that the 1.5 all ready have poor breathing passages your gonna be prone to a fast failure! the 1.6 were better engineered from what was learned by the 1.5 from VW!
JB weld just wont hold up to the constant heat and contraction of the crack!
i personally think it will leak after the first day!
Duane

[TurboJ]

So basically what you're saying is to upgrade to the 1.6.

It looks like you're running 18psi on a 1.5 block per your sig  :?:

I would make it a full 1.6.

1.6 parts are so much more plentiful that it'll be much easier in the long run.

[Rabbit on Roids]

i am running 18 on a stock block, 25 is about as high as you can safely go. i ran it for a long time with boost peaks of only 25psi. but one night i was racing a civic, and i was determined to stay ahead, so i neglected my gauges for a few seconds too long. i looked down at them after it went POP tho. my boost gauge was at 37psi. the whole end of the block after the #4 cylinder was trashed, pulled the threads right off the block. cracked the deck, and messed up the threads on 3 bolt holes.  well, pulled the threaded bosses clear out of the block. ok, enough of my storys..

ive had enough different motors under my hood tho. the two 1.5's ive had, have way more top end power than the 1.6's i could never get a 1.6 to spool my turbo to 30 psi like the 1.5's. i even had a 1.6TD that had a ported/gasket matched head, and that still didnt touch the performance i got out of my 1.5 motors. im not going by what people say about these motors, but by my own experiences. and personally, i think the ultimate cheap high rev diesel would consist of a turbo block & head with a 1.5 crank, rods and pistons(notched of course). i think it would be worth balancing the whole thing too, just because its a free upgrade. the 1.5 is a great engine, its just hard to keep a head on it under boost.

[blkboostedtruck]

why not a 1.5 crank in a 1.6 block? or better yet a 1.9 block?
i know it's been done the other way around!
i know the 1.5 do rev faster then the 1.6 and 1.9 thats always been the
advantage on the 1.5 with the right pump (a yellow dot pump!)
Duane

[Rabbit on Roids]

thats what i was talking about earlier, a 1.5 rotating assy in a 1.6 block. you have to use the 1.5 rods and pistons tho, as the rods are longer, and the wristpin-to-crown distance is also bigger. if you put 1.6 pistons on 1.5 rods, there would be nowheres near enough compression. the pistons wouldnt even protrude out of the block. ive done lots of thinking and comparing just to see if it were even possible. im way more partial to the 1.5 for its better top end. but there blocks are simply too weak. and i do have a yellow dot pump on it right now. i wanna modify, or pull the fuel limiter pin out of that pump and throw an LDA on it.

[drrtybyl]

I used this instead of JBWeld.  If it looks like it's going to open up I'll get the 1.6 machined and swap everything over.
It's a small hairline crack held together in multiple places -- makes me wonder how it got there.  The car was, after all, running with this and a leaky head gasket, heh.

[drrtybyl]

This may be a stupid question, but do any other modifications need to be made to a pump (internals, etc.) to add an LDA, or is the LDA simply a RRFPR-to-pump attachment?  From the looks of it, it just screws into top of the pump?  Would it possible to simply use a standalone RRFPR on that side of the pump instead of an LDA?

This mechanical fuel management stuff is still new to me..

[Rabbit on Roids]

rrfpr? i dont really know what your talking about there. but yea, an lda will bolt on a n/a pump, but it wont fuel like a turbo pump would. its got a fuel limiting pin in the side of the case. if you grind down, or remove that pin then it would work. and as for whatever you were talking about with the rrfpr, assuming its part of the pump.. i wouldnt mess with one

[drrtybyl]

Rising Rate Fuel Pressure Regulator.  Increases fuel pressure as boost is sensed..

[vanbcguy]

The Bosch pumps do it differently - they increase fuel quantity rather than pressure as boost pressure increases.  The LDA for all intents and purposes cranks up the fuel screw when it detects boost allowing more fuel to be injected.  There's no change in fuel pressure either within the pump or on the injection side.

[truckinwagen]

adding pressure to the inlet on the pump will have little affect as the low pressure pump in the IP is a positive displacement vane pump.

the vane pump will pump a certain volume regardless of pressure, and since diesel does not compress adding pressure to the inlet will not allow the vane pump to pump a higher volume the way you can do with air pumps.

[Rabbit on Roids]

yea, i agree with what he said ^ ^ ^
i like how he put it way more technical..
my brain doesnt work like that anymore.

[truckinwagen]

I meant that it would have little effect to how much fuel was pumped through the vane pump, but you are right about the internal pressure metering as well.