Page 7 of 7
Re: Math question tdi + 2 bar =
Posted: 21 Apr 2012, 21:48
by ..lee..
ok guys thanks for your inputs. question?
what do you think is a long term sensible boost level to run in a syncro camper?
i`m going to run this engine in as a totally std afn set up but once thats done i know i`m going to want a bit more. basically please post some solid advice so that once its in, and standard, " i`ll leave it the hell alone."

Re: Math question tdi + 2 bar =
Posted: 21 Apr 2012, 21:51
by max and caddy
i think standard boost is safe...maybe a smidge more fuel but if your engine can take it your gearbox is next in line to break...and thats more expensive!
Re: Math question tdi + 2 bar =
Posted: 21 Apr 2012, 22:45
by ..lee..
not worried about the box. Aidan`s extended the warranty.

Re: Math question tdi + 2 bar =
Posted: 21 Apr 2012, 23:38
by HarryMann
I didnt say it would bend the rods!
I didn't say you said it would bend the rods...
I was just making sure nobody in the conversation would be making that deduction, though I've been thinking whether that's really entirely right or not, pretty sure it is
... and excuse me for answering a question you asked me a while ago, which I've been meaning to answer for a while now
No, yes, maybe
Seems I'll have to be a bit more careful about smilies

I just happen to like the rolly eyes one, and use it in a number of ways, certainly wasn't meant as scornful or pointed (semantics I suppose)
Re: Math question tdi + 2 bar =
Posted: 21 Apr 2012, 23:54
by HarryMann
Lee.. depends on the exact engine spec. surely?
Would think 20~25 psi should be OK for most solid well built ones..
Water injection evens out and lowers the peak pressures in diesels and works well introduced at higher boost and fuellings
The 350 mph JCB DieselMax engines were using 80 psi, and basically 5 litre JCB 444 engines. Lots of inter and aftercooling as well as water injection.
Maybe it did spike, maybe either the piston crown didn't like the EGTs for too long or the rings or lands didn't like the peak pressures. Has the block distorted badly then, or is it the seizure that's written it off. The old AAZs had a habit of breaking a main cap occasionally, and needed web & skirt stiffening in that region. I don't know much about the Tdi blocks and what was done, but hear from all the Tdi folks that they have been progressively strengthened almost with each new release.
Exactly what limits the max boost on your setup, the turbines vanes alone, an external waste-gate or a BOV... Cheers
Re: Math question tdi + 2 bar =
Posted: 22 Apr 2012, 22:29
by max and caddy
Thats ok then...can be touchy at times! as you were.

Re: Math question tdi + 2 bar =
Posted: 26 Apr 2012, 20:31
by ..lee..
well with the vnt the ecu is supposed to limit the max boost along with the vane angle but the ecu was not controlling it correctly. that is going to be sorted before it all goes back together.
new problem arises. the pistons we were going to use were the hollow crown type as used in the higher hp tdi`s. trouble is we`ve found out that when these were fitted they also changed the oil squirters in the block, not a problem as we can swap them over too. big problem lies with the oil pump. apparently with the piston and squirter upgrades they also changed the oil pump spec and running the engine in the JX position useing the upgraded oil pump is not an option.
so. the question is, does the JX oil pump meet the requirements spec wise for the higher hp tdi`s ? or, can it be upgraded to meet the spec?
looks like i`ll be building the other engine up for now to std spec unless this oil pump issue can be resolved quickly. off to post on the tdi forum. fingers crossed.
cheers lee.
Re: Math question tdi + 2 bar =
Posted: 27 Apr 2012, 05:05
by footstuck
What's the issue mate. Is the body different height and different bolt hole config?
If so can you stick up a picture when you get a mo
Cheers mate
Re: Math question tdi + 2 bar =
Posted: 27 Apr 2012, 07:35
by ..lee..
Not sure what the difference is nick. I'm guessing the gears were changed in the pump but unless I can find out exactly what spec the later pumps are I can't determine whether these pistons can be run safely with the Jx pump. Need time to figure it out and it's time I have not got as engine needs to go back in ASAP
Cheers lee
Re: Math question tdi + 2 bar =
Posted: 27 Apr 2012, 07:59
by syncroandy
I'm not aware of that much variation on the EA827 style oil pumps, just the 'early' 30m depth and 'late' 36mm gear depth. I think the shaft length varies between 1.6/1.9 as well. Obviously pickup pipes vary according to the sump. Lee do you know what engine code the pistons, squirters and pump come from ? After the EA827 (early TDIs like ours) they moved to the chain drive oil pump which is completely different, eg. on the ALH VP pump engine.
Re: Math question tdi + 2 bar =
Posted: 27 Apr 2012, 13:47
by ..lee..
I'm not sure Andy. I think he was intending on using the pd 130hp pistons he terms them as hollow crown dont know if these pistons were ever a factory fitted to non pd tdis but will aparently fit our engines ????
Thomas HA Projeckt seems to think the Jx pump is fine. Going to commit to a std build for now but it would be nice to know for future engine builds if these pistons will work.
Cheers lee.