Turbo Xflow ... worth it?

[noisymime]

How much power and boost are you planning on? 7-9psi will be fine with the standard pistons and compression ratio

[Jack1995]

How much power and boost are you planning on? 7-9psi will be fine with the standard pistons and compression ratio

That's great that's all I'm after is 7psi roughly 150-180bhp??, how do I know how thick my decompression plate should be?

[Jack1995]

I've got these numbers on my cam...

771m6250 ? Any idea what it is?

[Dyno]

150 Bhp, possible, 180 Bhp, no, not with 7psi

You have to measure / calculate the compression ratio. Check internet how to do this.

[Jack1995]

Cheers mate that's great

[Jack1995]

I went for cheap and cheerful. So picked up a Garrett T15 from the local scrapyard for ~£70. Spools up by 1100rpm 8psi from my 1.3.

How much psi can I run comfortably on standard rods?

[bytesandbolts]

How much psi can I run comfortably on standard rods?

I ran 8psi no problem, will be attempting 1 bar when I add a boost controller.

[Graham]

How much psi can I run comfortably on standard rods?

the rods wont be an issue, std pistons will break long before the rods

[Jack1995]

the rods wont be an issue, std pistons will break long before the rods

Will piston s be OK then?

[noisymime]

Will piston s be OK then?

STD pistons are fine for 7psi, but I wouldn't go much beyond that with them.

[Jack1995]

STD pistons are fine for 7psi, but I wouldn't go much beyond that with them.

Should I be looking at forged pistons? Or is there a cheaper alternative?

[bytesandbolts]

Should I be looking at forged pistons? Or is there a cheaper alternative?

Noisymime summed it up perfectly. 7 psi or under run standard Pistons, assuming your CR is sensible. Over 7 psi look at forged Pistons.

[Jack1995]

My cr will be 8:1?

[Jack1995]

Apparently my cam is a standard 1300 cam? Will this be okay?

[bytesandbolts]

Sounds good to me

[Jack1995]

Sounds good to me

great stuff thats what i like to hear so dont run anymore than 7psi if i dont run forged pistons?
also with my engine spec is there anything else i should do?

[bytesandbolts]

great stuff thats what i like to hear so dont run anymore than 7psi if i dont run forged pistons?
also with my engine spec is there anything else i should do?

Just to reiterate my previous comment, I have a turbo xflow running at 8psi which blew a piston after two years due to suspected uneven fuel distribution. My point being im still learning myself so please don't blindly follow given advice. Keep the engine standard and invest in a good oil catch tank.

[Jack1995]

Yeah that's fair enough same here.

[bytesandbolts]

The catch tank I wish I put on when I first built. When under boost the engine will 'breath' quite a bit, especially if it's slighty worn like mine was.

Also why did you decide you want turbo?

[Jack1995]

The catch tank I wish I put on when I first built. When under boost the engine will 'breath' quite a bit, especially if it's slighty worn like mine was.

Also why did you decide you want turbo?

The basic idea was to get , relatively cheap power and stick with an original crossflow. I wanted both power and a Xflow and turbo was the cheapest easiest way I figured

[Graham]

The basic idea was to get , relatively cheap power and stick with an original crossflow. I wanted both power and a Xflow and turbo was the cheapest easiest way I figured

hmmm in practise turbo charging is rarely cheap or easy! especially if your looking to more than double an engines power output like you are.

[Jack1995]

So I've just taken my crank off and its scored around the main bearings. Are there any preferences on cranks?

[Jack1995]

hmmm in practise turbo charging is rarely cheap or easy! especially if your looking to more than double an engines power output like you are.

Well I'm stuck into it now so I am going to turbo it , its a different route

[Dyno]

I always see the same issues. People want a little bit more power and torque for little money and yes, turbo's can do this. Compared to other mods more torque (and power). But before they even start, they get greedy. Want more power as the original engine can safe stand. Because of more boost, installation also get more complex and you finally find yourself in a very expensive race engine build which you finally will NEVER build.

Keep it all simple and be happy with the power you can realistic find. If you build a standard KENT lower compression a little, fit Renault carb, get a double working actuator for the ignition (if needed), fit turbo with low boost (almost any engine can stand 500 Mbar on some even a little more) and you got yourself a nice engine.

[Jack1995]

Thanks onyd that's pretty much made my mind up. I was looking at forged pistons so I could run more boost but doesn't really seem worth it? Should I just settle for 150 bhp comfortably on around 7psi? I mean figures are floating around 200+ mark on higher pressure but will I gain more problems?

[Jack1995]

also my crank is scored so need a new one. should i be looking at a 1300 crank ? will that maybe lower compression slightly? or is there a better alternative?

[Dyno]

If you budget allow forged pistons, this is probably the best you can do. KENT pistons just don't look strong. The second thing you need to be sure of is a spotless oil system. Best pump, good quality oil, raised oil pressure (if possible bigger pump but don't think they exist for KENT) so more oil can flow and take heat with them and most important, a very good oil cooler. Don't forget a good gasket. Now you got yourself a billet road turbo engine, no not race.

I would not concentrate to much on power only. Even if you "only" end with 130 Bhp, the engine will feel like a big 2 ltr. Torque will increase and that's what makes you happy in a road engine. Better concentrate round your budget, if all is save up to 7 psi, go for it and see what power it makes and just be happy. Any other KENT engine making 130 Bhp in NA will feel slower. 150 Bhp, yes but if this is your first turbo engine,.... don't get greedy.

200 Bhp is a totally other story, after 200 you want 250 and by the end of the day 300 is also fine. Just send an email to Cosworth and ask for a quote. So you got at least an idea what's needed to convert a KENT engine into a F1 style turbo brick.

Again, turbo's can be very affordable in a basic form but also extreme expensive.

[Jack1995]

ive decided to go with a low budget build now it will become too expensive running forged pistons etc. im going to build it low priced and whatever i get is what it is.

next question if i run a 1300 crank and 1300 cam on 1600 rods and pistons will my compression ratio be ok ? looking to run the 2 head gaskets with a 2mm decomp plate? thanks al great help

[noisymime]

If you do have the pistons out, the best thing you can do if you want to keep them is get the crowns ceramic coated. These pistons just soak up heat which is the last thing you want with a turbo. Ideally they'd be forged with the coating, but it's better then nothing

[alladdin]

You won't be able to use 13 crank as too low compression .
Why not get a chambered head as already suggested ? One in 4 sale section.

[bytesandbolts]

Just for a benchmark I did my conversion for ~£1000, that includes turbo + scrapyard bits, Jenvey TB + bits, MS3X ECU and 1 day on the dyno.
1.3 110bhp with 121lbft.

[Jack1995]

If you do have the pistons out, the best thing you can do if you want to keep them is get the crowns ceramic coated. These pistons just soak up heat which is the last thing you want with a turbo. Ideally they'd be forged with the coating, but it's better then nothing

That's a great shout where can I get them done? And how much roughly?

[Jack1995]

So stay 1600 crank , rods and pistons. Keep 1300 cam and get a chambered head?

[Graham]

if it were me i would keep the head you have and machine some of the piston crown away, not only will it drop the CR but will make the piston lighter which is always a good thing

[Jack1995]

if it were me i would keep the head you have and machine some of the piston crown away, not only will it drop the CR but will make the piston lighter which is always a good thing

As well as compression plate?

[Graham]

personally i would avoid using a decomp plate if i could, its one more thing to go wrong,

i'll be honest i havnt done the maths as to how much needs to come off, but you wont need to remove shed loads of material, normal 1600 pistons give 9:1 Cr (1600gt 9.2:1) so it should be fairly easy to modify them to get the cr down to around 8.5:1, go much lower than that and the engine will be sluggish off boost

[Jack1995]

The piston is machined off a bit . struggling to upload a photo but it has had a bit taken off its bowled in the top and has cut outs for cam

[Dyno]

Agree with Graham. If Piston is standard 1600, not much has to be done to lower to 8,5. If you run 7psi, your save.

Don't fit a 1300 crank. Come on guys, you got a 1600, lower to 1300 and turbo charge it back to make a 1600 Bhp feeling? No, bad idea. Stick with the full 1600.

[Jack1995]

Agree with Graham. If Piston is standard 1600, not much has to be done to lower to 8,5. If you run 7psi, your save.

Don't fit a 1300 crank. Come on guys, you got a 1600, lower to 1300 and turbo charge it back to make a 1600 Bhp feeling? No, bad idea. Stick with the full 1600.

My pistons have been taken down but obviously I don't know my compression ratio now until I run it again ??

[Dyno]

No, I think you got it wrong. I believe you take "compression reading" for "compression ratio". We are talking about compression ratio so you have to calculate / measure the total capacity of the combustion chamber (gasket etc.. including) end calculate the compression ratio compared to the total engine displacement. This is very important and that the number we need. It should end at approx 8,5/1.

There are a lot of good readings about this on internet. Or just buy any silly tuning book. Most of these books are totally useless, copying each other but.... they all have the right calculations in it.