Tuning turbo time!
- Thread starter craigb244
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Tuning turbo time!
OP
OP
Thought i'd make and update here.
I have since done a couple of hundred miles since THIS thread. lifted the head quickly for a gander and it all looks fine. Im also VERY sure now that its not det. (A couple of marks on the head and piston look the same, and not positioned around hot areas) try get photos later.
I have resonantly ditched idle control as it was annoying trying to tune it, engine dont seem to need it anyway (idles fine even from cold)
Found and (maybe) fixed the knocking/tapping/slapping noise I had. Turns out that the head is a friday afternoon head, The cam bearing on the coil side also acts as a thrust bearing, it seems it was not made to the right spec and so once the oil was hot and thinner the cam could move in and out a small amount causing the cam to slap on the thrust bearing surface.
I "fixed" this by maring the bearing surface on each side a load of times with a punch (precision engineering here people!)
So as of now everything is going good BUT i have a bunch of new things to try out
I have since done a couple of hundred miles since THIS thread. lifted the head quickly for a gander and it all looks fine. Im also VERY sure now that its not det. (A couple of marks on the head and piston look the same, and not positioned around hot areas) try get photos later.
I have resonantly ditched idle control as it was annoying trying to tune it, engine dont seem to need it anyway (idles fine even from cold)
Found and (maybe) fixed the knocking/tapping/slapping noise I had. Turns out that the head is a friday afternoon head, The cam bearing on the coil side also acts as a thrust bearing, it seems it was not made to the right spec and so once the oil was hot and thinner the cam could move in and out a small amount causing the cam to slap on the thrust bearing surface.
I "fixed" this by maring the bearing surface on each side a load of times with a punch (precision engineering here people!)
So as of now everything is going good
BUT i have a bunch of new things to try out 
I "fixed" this by maring the bearing surface on each side a load of times with a punch (precision engineering here people!)
factory fitter spec!
OP
OP
hey my last job was rebuilding robotic servo motors and such and if the ball bearing outer race was loose we would do this and if its good enough for something cosing thousands then it is good enough for a old clanky fiat engine
hey my last job was rebuilding robotic servo motors and such and if the ball bearing outer race was loose we would do this and if its good enough for something cosing thousands then it is good enough for a old clanky fiat engine
oh i know, done it myself a few times
OP
OP
bit of a strange one...
today I decided to check all the major setting on my megasquirt.
got the old strobe out and fixed the ignition to 10degree.
now heres the strange thing. the timing was behind the 0degree marker! so the ignition was a good 15degree retarded the only thing ive changed since setting it was the whole engine so maybe something was up with the wheel/sensor position of the old block?
anyway ive fixed that and the lambda showed it to be running very rich so i got auto tune to lean everything out and the engine seems so much more crisp and awesome throttle response (always thought it was a bit crap due the low compression pistons)
the engine now sounds much better at high rpms where before it sounded strained. it now purrs and sounds eager all they way upto the limiter :slayer:
Did a little smoothing on the intake side of the engine and matched the ports as good as i could on the turbo manifold and turbo.
it now feels brilliant to drive and getting boost at around 1500rpm
today I decided to check all the major setting on my megasquirt.
got the old strobe out and fixed the ignition to 10degree.
now heres the strange thing. the timing was behind the 0degree marker! so the ignition was a good 15degree retarded
the only thing ive changed since setting it was the whole engine so maybe something was up with the wheel/sensor position of the old block?anyway ive fixed that and the lambda showed it to be running very rich so i got auto tune to lean everything out and the engine seems so much more crisp and awesome throttle response (always thought it was a bit crap due the low compression pistons)
the engine now sounds much better at high rpms where before it sounded strained. it now purrs and sounds eager all they way upto the limiter :slayer:
Did a little smoothing on the intake side of the engine and matched the ports as good as i could on the turbo manifold and turbo.
it now feels brilliant to drive and getting boost at around 1500rpm
I think the boost coming in ealrier is a lot down to the smoothing you've done..
When my manifold to turbo was done it made a big difference and came on boost a lot earlier than before which made it much more driveable everyday!
Good stuff
When my manifold to turbo was done it made a big difference and came on boost a lot earlier than before which made it much more driveable everyday!
Good stuff
Oh Crivvens, I hope modom is not reading this!!
Cheers
SPD
Cheers
SPD
OP
OP
its a huge difference! I had a look at the datalog last night and the lowest point i found boost (anything over atmospheric) was 900 or so rpm!!! this was with the car with 3 passengers at full throttle in 6th gear from an crawl.
I did it to get logs of areas of the map that are hard to reach but do run there for short periods.
I did it to get logs of areas of the map that are hard to reach but do run there for short periods.
OP
OP
Update:
Mot passed today. first time with the turbo. passed emissions (no cat )
In the couple of weeks before the mot it was off the road been treated to a few tweeks.
new handbrake and clutch cables. rear caliper mounts moded to allow the use of cinq hubs rather then the UT hubs (brings wheels in 5 or so mm)
machined and fitted some nylon spacers in the steering rack to stop wheels rubbing 6speed box.
New 6 speed box fitted. MUCH better ratios and a bolted diff ready for LSD.
turbo manifold internally tweaked and turbo raised up (allows better drainage of the turbo)
Boost and intake pipework changed, larger air filter and intercooler flushed out.
New aluminium radiator and coolant pipework changed .
oil cooler finally on the way to been fitted.
Megasquirt updated and tweaked (for emissions )
**** New Problems ****
Clutch slipping as soon as boost come on.
Not sure why but will see if it fixes itself (no oil coming from bell housing and clutch is only a few k old (stilo)
If not i will sort it when fitting diff.
Mot passed today. first time with the turbo. passed emissions (no cat
)In the couple of weeks before the mot it was off the road been treated to a few tweeks.
new handbrake and clutch cables. rear caliper mounts moded to allow the use of cinq hubs rather then the UT hubs (brings wheels in 5 or so mm)
machined and fitted some nylon spacers in the steering rack to stop wheels rubbing 6speed box.
New 6 speed box fitted. MUCH better ratios and a bolted diff ready for LSD.
turbo manifold internally tweaked and turbo raised up (allows better drainage of the turbo)
Boost and intake pipework changed, larger air filter and intercooler flushed out.
New aluminium radiator and coolant pipework changed .
oil cooler finally on the way to been fitted.
Megasquirt updated and tweaked (for emissions
)**** New Problems ****
Clutch slipping as soon as boost come on.
Not sure why but will see if it fixes itself (no oil coming from bell housing and clutch is only a few k old (stilo)
If not i will sort it when fitting diff.
maybe the autotestings killed the clutch plate? what boost you running at dude?
OP
OP
maybe the autotestings killed the clutch plate? what boost you running at dude?
well it seemed to of come on to quickly and the plate looked mint when i changed the box.
anyway just looked under the car after a long drive. tiny drip of oil hanging from the bell housing. i touched it and looking close could see bits of copper from the copper grease i used on the splines :bang: looks like the input seal on the box needs replacing (anyone know if i need to strip the box to change it??)
Im running around 0.7bar max. ive ran up to 1.2bar but any higher then 0.7 is not that fun on the road. most time I drive without the boost controller on so just about 0.3 at which i get really good MPG and a really nice drive and still able to **** off any boy racers :devil:
OP
OP
Engine and gearbox back out.
Gearbox stripped and rebuilt with new input shaft seal and bearing
Stilo flywheel at local machine shop been lightend (should be done monday)
Spare engine been put into use.
Not going to use 16valve pistons for this engine (want more compression)
For this engine i have milled a small amount from the top of the standard pistons (down to the valve pockets as not to weaken the pistons) this removed 4cc from the volume.
We then milled out the cylinder head to bring their volume to 28cc
This (from my calculations) should get me to near the compression ratio i want (8.5:1)
We are yet to polish up the combustion chambers and finish matching intake and exhaust ports.
Gearbox stripped and rebuilt with new input shaft seal and bearing
Stilo flywheel at local machine shop been lightend (should be done monday)
Spare engine been put into use.
Not going to use 16valve pistons for this engine (want more compression
) For this engine i have milled a small amount from the top of the standard pistons (down to the valve pockets as not to weaken the pistons) this removed 4cc from the volume.
We then milled out the cylinder head to bring their volume to 28cc
This (from my calculations) should get me to near the compression ratio i want (8.5:1)
We are yet to polish up the combustion chambers and finish matching intake and exhaust ports.
Attachments
Different approach always good to see
Is the metal thickness still OK? I know when Emma's dad looked at the std pistons there was not much metal to spare to keep "safe"
Did you consider skimming the head and block to the max? this should have given similar compression ratio overall (off course your method means you can exactly match cylinder volumes)
Is the metal thickness still OK? I know when Emma's dad looked at the std pistons there was not much metal to spare to keep "safe"
Did you consider skimming the head and block to the max? this should have given similar compression ratio overall (off course your method means you can exactly match cylinder volumes)
OP
OP
It "should" be thick enough. im guessing (From killing a damaged head) it should have 2-3mm Ive whacked with with a hammer and punch and it sounds solid enough.
I actually have a decomp plate that i could of fitted but i wanted to try something new.
The original plan was to remove enough metal from the head alone but i worried about going to thin.
I wanted to keep the original deck hight/valve to piston hight.
The amount of metal removed from the pistons wont be enough to weaken them
Pistons/pins/rods where balanced while apart.
I might of started with a engine that is harder to work with. The head was skimmed a lot and as it is a punto 75 the block is already decked.
Hopefully the metal removed from both sides of the valves will help them flow better (dont see why not)
I actually have a decomp plate that i could of fitted but i wanted to try something new.
The original plan was to remove enough metal from the head alone but i worried about going to thin.
I wanted to keep the original deck hight/valve to piston hight.
The amount of metal removed from the pistons wont be enough to weaken them
Pistons/pins/rods where balanced while apart.
I might of started with a engine that is harder to work with. The head was skimmed a lot and as it is a punto 75 the block is already decked.
Hopefully the metal removed from both sides of the valves will help them flow better (dont see why not)
nice to see something different. I take it theres about 1.5mm removed from each piston?
On the head, you havent gone any deeper than the valve seat itself have you?
On the head, you havent gone any deeper than the valve seat itself have you?
OP
OP
yes its just under 1.5mm from each piston. basically flattened them down till the valve pockets vanished.
no the head has not been machined lower then the seats
no the head has not been machined lower then the seats
fair enough.
reason i ask about the head is that i know a certain youth who machined a fair load out of his head to lower the CR, the head looked absolutely disgusting when it was done. He then proceded to have it mapped properly on a DTA... then blew the ring lands. IMHO it was super det caused by a very oddly shaped combustion chamber....
Not saying that yours looks bad at all, but just the principle of increasing chance of det and uneven flame fronts with a strange shaped combustion chamber was worrying me.
reason i ask about the head is that i know a certain youth who machined a fair load out of his head to lower the CR, the head looked absolutely disgusting when it was done. He then proceded to have it mapped properly on a DTA... then blew the ring lands. IMHO it was super det caused by a very oddly shaped combustion chamber....
Not saying that yours looks bad at all, but just the principle of increasing chance of det and uneven flame fronts with a strange shaped combustion chamber was worrying me.
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OP
OP
oops was it a fiat? did it look anything like mine?
making me worried lol.
making me worried lol.
nah it was a rover k-series of all things actually.
