High Compression 2.6L Astron.

[Superscan811]

Did it balance up ok?? that was alot of metal removed??
Hey, did you weigh it before / after??

I only removed 1.2kgs (18.4kg start - 17.2 finish) and it balanced up fine.
Most of the weight was removed from the extremities of the crank, where it does the most good.


Cheers.

[A57C]

.
the blocks do fail!!!!!!! they are average in design.. I personally believe the 4g5XX blocks are the weakest component..How do i know?? experience and working at a sigma wreckers 15 years ago.... I saw cracked blocks quite often.

hmm, no disrespect but i've never heard any hating on astron blocks before you
googling didn't turn up much either, so ...

[GLANT]

.
the blocks do fail!!!!!!! they are average in design.. I personally believe the 4g5XX blocks are the weakest component..How do i know?? experience and working at a sigma wreckers 15 years ago.... I saw cracked blocks quite often.

hmm, no disrespect but i've never heard any hating on astron blocks before you
googling didn't turn up much either, so ...

So???......Googling What???? ......heres a pic of my cracked block?? lol!.......was google even around 15 years ago?
And after many astron failures and lost $$$$.... No! im not a hater...im a skeptic!

Did it balance up ok?? that was alot of metal removed??
Hey, did you weigh it before / after??

I only removed 1.2kgs (18.4kg start - 17.2 finish) and it balanced up fine.
Most of the weight was removed from the extremities of the crank, where it does the most good.


Cheers.

good stuff!

[Superscan811]

And after many astron failures and lost $$$$.... No! im not a hater...im a skeptic!

Do you know if the blocks you used were out of a sigma or scorpion?
The Jap blocks are stronger because the casting is a bit thicker.

Here is some picks of the work I've been doing on the heads.

BEFORE


AFTER


Removed all sharp edges, de-shrouded and blended around the valve seats and sparkplug.

I have to cc the chambers but that will be done after the valves are installed.

Ive also blended/smoothed the port castings as well as reduce the webbing around the valve guides.

Cheers.

[brendon]

Do you know if the blocks you used were out of a sigma or scorpion?
The Jap blocks are stronger because the casting is a bit thicker.

that's interesting news....cheers for that. if correct I'll be reblocking with a scorpion block.
do you have any measurements/photos to back up the claim.

is it just sigma blocks that are weaker. would pajero ones be thicker/stronger

[Xaser]

15 days without news??? come ON!!!!

[Superscan811]

do you have any measurements/photos to back up the claim.

Both Scorpion blocks are at the engine re-builders at the moment but I hope to have them back next week, I'll take measurements for you then.

15 days without news??? come ON!!!!

Sorry for the delay, my plans are very fluid and change often as new problems or ideas come up and I prefer to have solid information before posting.

Bought a 4D56 crank (95mm stroke) which will make it a 2.5L high compression (between 12:1 - 14:1 compression ratio).
The mains on the 4D56 crank are 66mm but I should be able to turn them down to 60mm.
The bigends are the same along with all the other measurements and spacings so this means I can just use a 2mm copper head gasket and not have to machine the pistons at all.

Looks like I'll have to knife-edge the 2.5L crank. and use the 2.6L crank for a future engine build.

I will try and post a bit more often.


Cheers.

[Xaser]

>WAM....

4D56 fit on 4G54 and 4G52???

[Superscan811]

Well I've sent the 4G56 crank off to be ground and should have it back late next week.

Total cost will be around $600 (including buying the crank for $175), which includes machining, grinding and after I finish the knife edging, a balance.

It's more than I was wanting to spend but in the long run, it will save me some time and money, ie: machining the pistons and purchasing/making a de-compression plate.

I could have just used the 2.0L crank but there is no replacement for displacement.

I should also be able to drop the cost by $200 next time (if this works out) by machining the mains myself before getting it ground to spec.

Currently I'm developing the rocker modifications.
1. Both the rockers and the posts will need to have sleeves with thrust surfaces.
2. The rockers will then be drilled and an oil channel will have to be machined, to allow oiling to the "swivel foot" tappets.
3. The spacers (instead of the spring retainers) will have to be measured and made. May also have to fix them to the rocker posts so they don't rotate.

Not much of an update but next week I will include a few more pics.

Cheers.

[GLANT]

short collars with grub screws? makes them adjustable.. if you use aluminium to make spacers, it would be same "alloy" thrust surface as factory..the idea is to have no load what so ever on rockers..........
crank!!

[Superscan811]

short collars with grub screws? makes them adjustable..

I'm nickel plating the rocker shafts so I prefer not to mark them with grub screws.

The bushing material will be aluminium-bronze. It lacks "embedability" but since I'll be running a bypass oil filter, it shouldn't be an issue.
It also is a bit harder than straight aluminium and tends to gall less which means on startup, when there is no oil, the rockers and shafts won't be damaged as much.

...the idea is to have no load what so ever on rockers...

. Planed on having around 1mm of "float" (0.5mm per side of center) for the rockers. That should be more than enough.

Also, the rocker shafts I'm using are off a hydraulic lifter head because they already have the extra oil holes on the shafts.

When I sandblasted the rocker shafts in preparation to plating them. it looks like Mitsubishi has only hardened the steel where the rockers are placed.
Guess it costs .5c less than doing the whole shaft.

Drilling the 1/16" hole through the non-hydraulic rocker is proving to be a bit of a pain.
Luckily I have several damaged rockers to practice with.

Cheers.

[GLANT]

Drilling the 1/16" hole through the non-hydraulic rocker is proving to be a bit of a pain.
Luckily I have several damaged rockers to practice with.

what about drilling a larger hole... with the 1/16th hole just at the end??

[amgis_obrut]

you sticking 7mm valves in that head ??

[Superscan811]

what about drilling a larger hole... with the 1/16th hole just at the end??

The problem is the thickness of the rocker beam. 1/16" is about as large as I would want to go. Any larger and it might weaken the rocker too much.

you sticking 7mm valves in that head ??

Yep, 7mm stems in the exhausts and 6mm stems in the inlet.

Cheers.

[Superscan811]

Some more pieces to add to the high compression engine.

The 4D56 Turbo Diesel crank, with the mains ground down from 66mm to the standard 4G54 60mm, it has a 95mm stroke instead of the 4G54 98mm stroke.

Still needs to be knife edged and lightened a bit before I get it balanced.
The only other thing I noticed was the placement of the keyway closest to the first mains being around 7mm further away, but it shouldn't be an issue.


AND

the 4G52/4G54 Forklift oil pump

The machining is a bit rough, ie: lots of burs that could come off and go through the engine, so I'll be cleaning it up a bit.

Just waiting on the gears Matt.

Cheers.

[brendon]

do you have any measurements/photos to back up the claim.

Both Scorpion blocks are at the engine re-builders at the moment but I hope to have them back next week, I'll take measurements for you then.

How'd you go with this?

[brendon]

Both Scorpion blocks are at the engine re-builders at the moment but I hope to have them back next week, I'll take measurements for you then.

Sorry to 'bump' again, just wanting to know if you had them back yet and had a chance to measure them. I understand everyone's busy so that's cool.
Its just I'm holding off getting a replacement block till I have some more details

RPW said in relation to their Drag Galant:
There is no stronger or weaker block in the 4G54 range, although as a preference we try to stay with either Magna or Pajero engine block.
Japanese blocks may be slightly stronger but ultimately the cracking can happen to any block

i assume the use of a magna/pajero block is due to being a later casting, Mitsubishi might have ironed out some issues also more common car (magnas anyway)

[Superscan811]

brendon, I haven't forgotten, just been a bit busy the last fortnight.

Cheers.

[brendon]

No worries, whenever you get a chance

[astronturbo77]

magna 2.6 blocks are thinner in the cylinder walls than a GN 2.6 block, i have measured them myself. if this is relavent to what you are after?

[Superscan811]

Just a few pics to give you a bit of an idea what I am talking about (still haven't got my blocks back yet).


This first pic is is of my GN wagon block, complete with silicon crack repair and silicon welch plug repair.
This is where most of the AUSSIE made blocks will crack with NORMAL use. Note the vertical rib half way between the plugs, it's the same height as the top of the welch plugs (same for the Magna block).



The Magna block is very similar to the GN block, even with the verticle rib between the plugs.



The Scorpion block (not a very clear pic but good enough).
No central rib, the casting on the raised section between the welch plugs is thicker (does not go go in as much as the GN and Magna blocks).



Again, will post actual measurements when I get the blocks back.

Cheers.

[amgis_obrut]

your running efi and a sprint 500 on this hey

so this might come in handy http://cgi.ebay.com/ebaymotors/MK1-CRAN ... 2442wt_734

also if you go coil near plug i highly recommend the LS2 truck coils (ac delco d585) these are an oem extreme duty coil and have a built in heat sink

[Superscan811]

your running efi and a sprint 500 on this hey so this might come in handy "CRANK PULLEY WITH EDIS TRIGGER WHEEL"

I have 2 of his short shifters, 2 adjustable cam gears, and a few inlet flanges I designed, but he made for me.

All good items but I'm not totally sold on the aluminium crank pulley.

Will be using a CRANK angle sensor of some type but initially it'll be running carbies, just to run it in and check all is well.
No point building a new engine only to stuff up the run-in because the EFI needs to be setup correctly.

also if you go coil near plug i highly recommend the LS2 truck coils (ac delco d585) these are an oem extreme duty coil and have a built in heat sink

Bought a Dual CDI unit Dynatek ARC-2 CDI which will allow me to run a wasted spark system.
Initially, for the coils, I'll be running the VR4 coil pack. These are compatible with the CDI unit.
Almost finished modifying the standard dizzy to be able to run these coils.

Cheers.

[Superscan811]

Do you know if the blocks you used were out of a sigma or scorpion?
The Jap blocks are stronger because the casting is a bit thicker.

that's interesting news....cheers for that. if correct I'll be reblocking with a scorpion block.
do you have any measurements/photos to back up the claim.

is it just sigma blocks that are weaker. would pajero ones be thicker/stronger

Here is a few more pics.

Aussie Block.


And the JAP.
Note:
1. The surface for the oil squirters are already cast into the block for the Turbo build
2. The No:3 and No:4 mains have extra webbing.
3. The No:3 and No:4 main caps are thicker.




Cheers.

[brendon]

cheers for that.

hows the build coming along?

[Superscan811]

hows the build coming along?

Slowly.
My wife decided to install a new hood ornament on the Targo (a cement post).
Needless to say, the Tarago didn't look too good after the installation.
With the floods over in Japan, any new car parts that are required, are taking months to arrive.
So we are down to 1 car, the wagon.
As the motor in the wagon is a bit tired, I have now built another one, but between my wife using the car morning, afternoon and night, I haven't even been able to install that one.

At a guess, It'll be another month at least before I get a chance to finish the High Comp engine.

Cheers.

[Benno]

Good Work Superscan811 except for the tarago

It will be interestimg to see the outcome from the build

Keep us posted on the engine build

[BOOTS]

great thread... more please

[Xaser]

[Superscan811]

Well a good bit of news is I finally have the engine blocks back.

It's taken a bit longer than I anticipated, but the build is still on...

Also picked up the block for the turbo build.

Pics in a few days.

Cheers.