sorry we have yet to strip the old engine to see if it had a decompression plate...for now the new standby engine does not have a decompression plate and it feels exactly like the old engine...but with a bit more pickup...will strip the engine donw over the next few days...and then its getting rebuilt with balanced crank uprated bottom end maybe steel pistons and forged rods if the bore is good...am just wondering if the engine will take a bore out to increase the piston surface area...some one mentioned it one here before I think...there isnt much metal to take a bore out...? anyone know for sure...
update on projects
- Thread starter paulob1
- Start date
Help Support ProjectPuma:
pumanoob,
your thoughts...
inlet body 58mm...worth the cost or not.
change the pipes and fit intercooler for sure. this is happening...will go 2.5 inch i think, maybe 3 if I can fit them in, without the battery in the way I think I can make the room for all this.
change the injectors, I think not at this stage...will see what megasquirt thinks..?
mild head polish and port and bigger cams either frp, I have spare or some proper turbo cams...? I dot want more than 220 at this stage..but would be happy if I can get more. I suspect the bottom end is limited to 250 reliably..
anyway your thoughts..
your thoughts...
inlet body 58mm...worth the cost or not.
change the pipes and fit intercooler for sure. this is happening...will go 2.5 inch i think, maybe 3 if I can fit them in, without the battery in the way I think I can make the room for all this.
change the injectors, I think not at this stage...will see what megasquirt thinks..?
mild head polish and port and bigger cams either frp, I have spare or some proper turbo cams...? I dot want more than 220 at this stage..but would be happy if I can get more. I suspect the bottom end is limited to 250 reliably..
anyway your thoughts..
PumaNoob
New member
Your going through engines like theres no tomorrow!! Was it being driven hard when it went?
How much is the 58mm throttle body? If its cheap enough its gotta be worth a few horses. I dont think it will make a massive difference because the turbo outlet is only 50mm OD, so ID would be 40-45mm. But then you have a butterfly in the middle of the throttle body so if its not a major expense, it cant do no harm.
If you got a GT28R with a 2.5 downpipe and free flowing exhaust and lower compression, i think youll be looking at well over 220. Id have thought youll max out the injectrs first. My main worries were the if the engine and gearbox could take the power. The puma engine is an awesome engine, its a shame it werent used in more applications, then there might more performance parts available at a more competative price. If i could get pistons and rods for the price i got the duratec ones, i never would have changed to the duratec.
How much is the 58mm throttle body? If its cheap enough its gotta be worth a few horses. I dont think it will make a massive difference because the turbo outlet is only 50mm OD, so ID would be 40-45mm. But then you have a butterfly in the middle of the throttle body so if its not a major expense, it cant do no harm.
If you got a GT28R with a 2.5 downpipe and free flowing exhaust and lower compression, i think youll be looking at well over 220. Id have thought youll max out the injectrs first. My main worries were the if the engine and gearbox could take the power. The puma engine is an awesome engine, its a shame it werent used in more applications, then there might more performance parts available at a more competative price. If i could get pistons and rods for the price i got the duratec ones, i never would have changed to the duratec.
nah the good news is it was the air intake hose knocked off one of the sensor clips, simple. just annoying...but she is running very sweet and once we replace the clutch I will be off to dyno land and see what we have. for this car I dont want to change the turbo, just improve it a tad...with the intercooler and the bigger cleaner air intake and pipes and that 90degree elbow removed and maybe a diffuser box on the back of the turbo to aid flow, plus a new manifold I think I will be happy with 200 bhp, or a bit more, now we have the new chassis she is running a lot straighter and feels like a puma again...
I can get a full set for 700 quid, rods pistons and bearings...so likely will rebuild the original turbo engine wth this set up, reduce the compression a tad and port the head a bit, polish it up, even a 5% increase will help, and then fit this engine into another FRP...removing the frp engine and storing it for future use...and then fitting either the T25 or T28 and aiming for 250 instead of 220...but agree injectors will need to be uprated, must sit down and work out the fuel supply needed at 250 bhp-350bhp then work out the fuel pump needed and the injectors needed with a bit of spare... ...anyone know what size the std injectors are...? I understand you can get 350 cc injectors, that should be easily good enough for 300-350 bhp with a bit to spare...
I am thinking now that the larger throttle body would be better for the std engine more than for the turbo engine...
I can get a full set for 700 quid, rods pistons and bearings...so likely will rebuild the original turbo engine wth this set up, reduce the compression a tad and port the head a bit, polish it up, even a 5% increase will help, and then fit this engine into another FRP...removing the frp engine and storing it for future use...and then fitting either the T25 or T28 and aiming for 250 instead of 220...but agree injectors will need to be uprated, must sit down and work out the fuel supply needed at 250 bhp-350bhp then work out the fuel pump needed and the injectors needed with a bit of spare... ...anyone know what size the std injectors are...? I understand you can get 350 cc injectors, that should be easily good enough for 300-350 bhp with a bit to spare...
I am thinking now that the larger throttle body would be better for the std engine more than for the turbo engine...
PumaNoob
New member
There is debate as to the flow rate of the standard greens, but i believe them to be between 260-280cc. I think you will max out that turbo if you are keeping the saab turbo, before you max the injectors. It will only boost to 12psi max at high revs, more lower down, but i think it becomes inefficient after about 10 psi. But with the downpipe sorted and the intercooler, it will be almost the same set up as mine, mine is 230, if you have standard compression, as long as it dont detonate, you should be pushing more power then mine.
okay I did a 250 mile round trip in turbo today, running real sweet apart from the cltuch and brake wobble. cant make my mind up if its tracking or rotor problems, on hardish braking there is no wobble at all, on slow speed, light braking the wobble appears. To me that sounds like wheel and alignment problems rather than rotor issues but I suppose it could be both.
The clutch will be done this week and then I will have it tracked and then see what is going on...dyno.
ordered 16 row cooler from matty
have the intercooler ready, air con unit removed already
then will start fitting megasquirt, want to measure inlet air temp, outlet from turbo and outlet from intercooler, to see what goes on...will then fit the larger pipes and maybe a diffuser onto the end of the turbo to aid flow and possibly improve boost.
I think you are fright about the boost it wont go much above 12 psi, its making 9psi at the moment and is totally sweet...has real get up and go even with the errant clutch...
The clutch will be done this week and then I will have it tracked and then see what is going on...dyno.
ordered 16 row cooler from matty
have the intercooler ready, air con unit removed already
then will start fitting megasquirt, want to measure inlet air temp, outlet from turbo and outlet from intercooler, to see what goes on...will then fit the larger pipes and maybe a diffuser onto the end of the turbo to aid flow and possibly improve boost.
I think you are fright about the boost it wont go much above 12 psi, its making 9psi at the moment and is totally sweet...has real get up and go even with the errant clutch...
PumaNoob
New member
let me know what you come up with on the brakes, sounds exactly like mine, when you brake really hard, like emergency stop, there doesnt seem to be an issue, but with light braking, it violently shakes at high speed. Im going to fit my brembo brakes tomorrow to see if the problem goes away.
Megasquirt is great for logging, also might be a good idea to get an EGT sensor to log. You can see pretty much anything thats going on with it by just looking at the log.
Could be excessive heat caused the plug to break, possibly detonation or pre ignition. Are there any signs of det or pre ignition on your other spark plugs? with 9 psi of boost, on standard compression with no intercooler, im very suprised its lasted as long as it has. Shows what a good engine it is.
Megasquirt is great for logging, also might be a good idea to get an EGT sensor to log. You can see pretty much anything thats going on with it by just looking at the log.
Could be excessive heat caused the plug to break, possibly detonation or pre ignition. Are there any signs of det or pre ignition on your other spark plugs? with 9 psi of boost, on standard compression with no intercooler, im very suprised its lasted as long as it has. Shows what a good engine it is.
We have strated to strip the old engine, it did not have a decompression plate, it did not have any internal mods...the rings and bores look normal but the head is pitted and has been very poorly skimmed. The head gasket is a reall cheap one and there does not seem to be any obvious reason for the heavy breathing...the head we will not use again.
The latest head is not off yet, but it looks like either detonation or a faulty valve. Anyway this engine is now getting the works, I still did not get to dyno it but am assuming 180 bhp before it broke.
we are now fitting the intercooler, the new clutch a new old head and a proper ford head gasket. Not sure if I am going to go with a decompression plate either as i only want 200 -230 max out of this car...lOOKING AT REMOVING THE VCT BUT IT DOESNT LOOK THAT EASY...ANYONE DONE IT ON HERE...
Then fit megasquirt and get some information about what is going on...
the brakes are going to hi spec for checking skimming if possible and or new rotors...
The latest head is not off yet, but it looks like either detonation or a faulty valve. Anyway this engine is now getting the works, I still did not get to dyno it but am assuming 180 bhp before it broke.
we are now fitting the intercooler, the new clutch a new old head and a proper ford head gasket. Not sure if I am going to go with a decompression plate either as i only want 200 -230 max out of this car...lOOKING AT REMOVING THE VCT BUT IT DOESNT LOOK THAT EASY...ANYONE DONE IT ON HERE...
Then fit megasquirt and get some information about what is going on...
the brakes are going to hi spec for checking skimming if possible and or new rotors...
PumaNoob
New member
Ive not removed VCT, but you can just unplug it to stop it working, unless there was some other reason you wanted to remove it. When i was playing with cam timing on mine, i tried different combinations of cam timing, and with and without the VCT, and every time, it worked better with the VCT connected, but that was only with standard cams and FRP cams, you might find a ddierent cam that works well without VCT. To run over 200bhp on a 10.3:1 compression engine, if you want it fairly reliable, your going to need to run it very rich on high octane fuel, which will in turn loose you a little power, and the spark timing and fuel corrections on your ecu will need to be very well tuned. You arent leaving yourself much room for error or fuel quality. Even the very high compression mazda MPS only has 9.5:1 and the subaru impreza WRX has 9:1. Is there a reason you dont want a ecomp pllate? It just seems very risky, why would you not want your engine to be safer and more reliable for the sake of a £40 plate?
Its your engine, and you seem to have some fairly good knowlege on what you are doing, so im sure there is a reason for you doing it the way you are planning to. For an engine that isnt designed to be turbocharged, it makes sence to take all the precautions you can, unless its going to cost you more then the project is worth.
Its your engine, and you seem to have some fairly good knowlege on what you are doing, so im sure there is a reason for you doing it the way you are planning to. For an engine that isnt designed to be turbocharged, it makes sence to take all the precautions you can, unless its going to cost you more then the project is worth.
my thoughts...
I want to build a simple kit so I can sell it so that it simply bolts on...this means as little mechanical change as possible...if people can achieve 180-200 without the decompression palte and remain reliable we should have a winning solution...however given that the plug on the last engine may have been destroyed through detonation then I may reconsider this...
the last engine that has gone...it looks like the rings on 1 and 4 were shot. not stripped them out yet but they are leaking significantly more than the center two pots...
the valve on new engine with the broken plug seems to be damaged in some way, not sure until we take the head off so will see once done...damn annoying that...but no problem...
I want to build a simple kit so I can sell it so that it simply bolts on...this means as little mechanical change as possible...if people can achieve 180-200 without the decompression palte and remain reliable we should have a winning solution...however given that the plug on the last engine may have been destroyed through detonation then I may reconsider this...
the last engine that has gone...it looks like the rings on 1 and 4 were shot. not stripped them out yet but they are leaking significantly more than the center two pots...
the valve on new engine with the broken plug seems to be damaged in some way, not sure until we take the head off so will see once done...damn annoying that...but no problem...
PumaNoob
New member
Oh ok, i think i remember you saying now that you want to test it to destruction, at least we will know where the limits are! But the problem with a bolt on kit, is fuelling. If you could somehow figure a good plug in fuelling mod, people would be biting your arm off for kits, theres a hell of a lot of interest in turbocharging, and the kit would fit fiestas and 1.4 and 1.6 focus to, with a little modification to downpipe. I tried a 5:1 FMU, and it overfuelled, but if you were to get a 2:1 at a good price, i think youd get fuelling pretty good too.
Youll make it to that rolling rd one day!!!
Youll make it to that rolling rd one day!!!
I think we will have to provide a megasquirt installation with the kit...unless we can develop a simple plug in chip mod. Easy enough to do and i have the staff to do that so it may be a plan...too busy trying to make money and keep head above water in the current market so have a lot to do...
Flying Scotsman
New member
paulob1 said:
Weak knowledge entering the conversation here...lol
Would some sort of uprated/strengthened rings and vavles do the trick?
RE. Decompression plate, is this added to the piston or are these new pistons altogether?
Reason i ask, is that i wouldn't want this happening to mine when i do it, so im learning from your misfortunes... sorry.... where would one get such items?
Burton Power?
madhillbilly17
New member
hi mac, its a plate that goes in between the block and head with 2 head gasket either side, it lowers the compression so you can run more boost safely.
Flying Scotsman
New member
madhillbilly17 said:
Ah i get it... like a flange almost.... where would i get one of these or would i have to get one fabricated?
PumaNoob
New member
The decompression plate increases the size of the combustion chamber. The more air and fuel you can get into a combustion chamber, the bigger the bang (as long as that mixture isnt to hot). The lower the compression ratio, the less the gas in the combustion chamber is compressed so less heat is produced, so safer running all around. You can email [email protected] for one, i think they are about £50. Its the same sort of idea as low compression pistons, but the pistons increase the volume of the combustion chamber by having a dish in them, or having the head of the piston skimmed.
The downside to lower compression is that there will be slightly more lag, and pound for pound of boost, there will be slightly less power.If theres 200bhp on a 10.5:1 engine at 10 psi, on an 8.5:1 engine, there will be about 190bhp. But then you can safely run about 18 psi of boost in an 8.5:1 engine, up to about 22psi with high octane fuel and an air fuel ratio of about 11:1 and the right ignition mods. With a decent turbo that would see the 1.7 past 300bhp with the right mods and strengthening. At 10.5:1, i really wouldnt push the boost past about 10psi, and thats only with the right mapping and fuelling. Lower compression gives you more scope for error and fluctuation in temperature and fuel quality and ecu lag (it takes the ecu time to process information and send the cerrect signals to the injectors and the sparkplugs)
The downside to lower compression is that there will be slightly more lag, and pound for pound of boost, there will be slightly less power.If theres 200bhp on a 10.5:1 engine at 10 psi, on an 8.5:1 engine, there will be about 190bhp. But then you can safely run about 18 psi of boost in an 8.5:1 engine, up to about 22psi with high octane fuel and an air fuel ratio of about 11:1 and the right ignition mods. With a decent turbo that would see the 1.7 past 300bhp with the right mods and strengthening. At 10.5:1, i really wouldnt push the boost past about 10psi, and thats only with the right mapping and fuelling. Lower compression gives you more scope for error and fluctuation in temperature and fuel quality and ecu lag (it takes the ecu time to process information and send the cerrect signals to the injectors and the sparkplugs)
Flying Scotsman
New member
You mentioned the right mods and strengthening and ignition mods.... could you elaborate please?
PumaNoob
New member
Well a standard engine wouldnt be able to take 300bhp, and im not sure the head would flow enough for 300bhp either. The dynamic compression ratio increase from the turbo would increase power to a certain extent, but you can only increase that so much without it going bang. If i was going for massive power with the 1.7, id look at a good set of main bearings, a good set of big end bearings, stronger con rods, stronger pistons with a thicker crown to help disperse the heat, id go for alchol injection to cool the charge down, the head would have to be flowed properly and bigger valves and valve seats fitted, and of course the right turbo would need to be used, for peak figures id go for a GT2071R or even a GT30, loads more lag, but top figures produced. For drivability and lower down power id go for GT28R or possibly GT28RS (thats what i have on my 2.0). The smaller turbos are slightly harder to get bigger top end power from, without going past its peak efficiency.
Turbo size is a very important factor, and the use of the car would be the main decider. A 1.7 with a GT30 on would be virtually un-usable on the street, you could drive it but the power would be so unpredictable because youd have about 100bhp, then at about 5500rpm-6000rpm, youd get another 200 horses thrown into the mix! But it would be good on a drag strip, once your in boost, nothing will catch you!!
P.s if you want to continue with this topic, it might be better to talk on the turbo talk thread rather the cluttering up Pauls project thread, unless Paul is ok with it??
Turbo size is a very important factor, and the use of the car would be the main decider. A 1.7 with a GT30 on would be virtually un-usable on the street, you could drive it but the power would be so unpredictable because youd have about 100bhp, then at about 5500rpm-6000rpm, youd get another 200 horses thrown into the mix! But it would be good on a drag strip, once your in boost, nothing will catch you!!
P.s if you want to continue with this topic, it might be better to talk on the turbo talk thread rather the cluttering up Pauls project thread, unless Paul is ok with it??
