Author Topic: ID-DI crosbreed engine thoughts (Read 5047 times)

burnt_servo · « **Reply #15 on:** March 06, 2008, 02:50:43 pm »

justa quick search around and it looks like ross can make a set of custom pistons , but a guy is looking at around 230.00 per piston , min 4 pistons per order .

anyone have a busted up piston that they can cut and measure the thickness of the dome ?

jimfoo · « **Reply #16 on:** March 06, 2008, 02:58:53 pm »

What kind of piston?

greg123 · « **Reply #17 on:** March 06, 2008, 03:13:43 pm »

Only a factor of 10 out then.. :shock:

Ok that's a bit different. Deffo some room for grooves or a bit of messing around, not sure about a bowl though, but who knows. Not sure what you could do with that anyhow, unless you could get some sort of super long injector nozzle, fill the pre-comp up and drill a hole just so the nozzle pokes out of the head and into the bowl in the piston, di style.

I still say turning the pre-comp into a DI chamber, use a di style injection and CR and keeping the IDI flat top piston, maybe with some guide grooves, may have some miliage.

The crossbreed liveth, if only in theory....

Greg.

Quote from: "jimfoo"

I meant cm, not mm :oops:

burnt_servo · « **Reply #18 on:** March 06, 2008, 09:08:06 pm »

Quote from: "jimfoo"

What kind of piston?

it was a diesel piston , built to how ever you wanted it , they gave a series of bore sizes , and a price for each size range .

burnt_servo · « **Reply #19 on:** March 06, 2008, 09:17:16 pm »

Quote from: "prothe"

I don't like the idea as presented, but it brings up some interesting concepts.

First of all, why make special pistons. Too much trouble. I know... I should have 1.6 TDI pistons in 2 months.

It's the reusing the 1.6D head for an TDI idea that is interesting to me. Can the combustion chambers be competely closed off and used as a mount for the TDI injector? I haven't messed with those prechamber inserts (so I'm just thinking out loud), but if they can be removed and replace, can they be changed become a TDI injector holder?

I'm trying to offer a 1.6 IDI to TDI conversion, and being able to reuse the old head would really help keep the costs down.

if you go back to the first post it mentioned something about burning veg oil .......

it got me to thinking about burning veg oil , while heating it as little as possible .
one of the problems is having burning oil running across the tops of the piston , hitting the wall , and getting into the rings while still burning ( like a bad overfueling problem ) thus killing your rings .

also the compresion on a 1.6 is like 23 to 1 ..... put that head on a 1.9 idi bottom end and it goes up some more , which means you have some room to play with , in theory , in opening up the bowls / or bowl in the piston . this would help keep the burning oil in the center of the piston , rather than running across the relitively flat surface of the piston crown and into the rings .

even just making the swirl chambers in a idi piston bigger and deeper might have a postive effect .

Slave2School · « **Reply #20 on:** March 07, 2008, 03:27:16 pm »

If I understand things correctly isn't making a larger cup n the head going to increase the pressure felt on the head by a significant amount even if the compression ratio is lowered?

burnt_servo · « **Reply #21 on:** March 07, 2008, 04:40:06 pm »

Quote from: "Slave2School"

If I understand things correctly isn't making a larger cup n the head going to increase the pressure felt on the head by a significant amount even if the compression ratio is lowered?

your talking about making the precombustion chambers in the head bigger ?

i'm thinking outloud about making some sort of bowl area on the top of the piston that the precombustion chamber would empty into .

as you increased the internal surface area of the precombustion chamber , the act of combustion would exert more actual force on the head ..... but the weak point would still be the headgasket sealing area

NewbeeMC9 · « **Reply #22 on:** March 07, 2008, 10:46:16 pm »

This fella is putting together a kit to make a 1.6IDI into a TDI. I'm gonna ask him about it and if he would consider the elsbett piston. I'd prolly doit just for that. i'm gonna place an order to him after I check my compression for some stuff

http://www.dieselvw.com/

first timer, great board

jtanguay · « **Reply #23 on:** March 07, 2008, 11:15:43 pm »

seems to me like it would be more work than it would be worth to try and install TDI injectors into an IDI head...

better off finding a bare head that accepts the TDI injectors and camshaft/valves/lifters from a 1.6. it would probably run really good with a fresh head too! as long as the camshaft isn't bent or anything :lol:

Slave2School · « **Reply #24 on:** March 10, 2008, 01:02:44 am »

Glow plugs will be needed if you want to drive below 2-3c unless you have a back up plan of course. I think an intake heater would be OK or a perm mounted bottle of ether like we have on the mules at work.

burnt_servo · « **Reply #25 on:** March 10, 2008, 01:52:37 am »

instead of glow plugs , make a grid heater off of a 5.9 cummins fit to the intake .

mattbondy · « **Reply #26 on:** March 10, 2008, 04:44:21 pm »

How about some kind of reshaped injector, possibly installed from the other side? That would take up some of the volume and allow for new spray patterns, etc. I would imagine that would be a lot cheaper than custom pistons.