Discussion
First of all these
Then hopefully be able to turn the wick on the nitrous a little more.
Will also be fitting new driveshafts so i can launch harder.
While the engines semi stripped will be porting the inlet manifold and trumpet base some more and checking the heads over.
What else to do?
Ultimate aim for 2015 is a 10.5 from the little 4.6
Then hopefully be able to turn the wick on the nitrous a little more.
Will also be fitting new driveshafts so i can launch harder.
While the engines semi stripped will be porting the inlet manifold and trumpet base some more and checking the heads over.
What else to do?
Ultimate aim for 2015 is a 10.5 from the little 4.6
phazed said:
The poor little 4.6, it had such an easy life with me!
How much more porting can you do on the trumpet base/inlet?
I dont think my inlet will be anywhere near yours Peter.How much more porting can you do on the trumpet base/inlet?
I just want to spend a few hours opening from the top and tapering right through to the head.
I believe there is a few bhp lurking for free there still.
They come in different thickness' so can help with varying CR, made from layers of metal, very strong seal and are apparently reusable. £100 for the pair. I can vouch for them, but the surfaces of block/head have to be of a good [smooth] finish, dry with no sealing compounds used. I went for these over copper and 'o' rings after recommendation on here from someone.
Edited by macdeb on Friday 5th December 21:36
macdeb said:
They come in different thickness' so can help with varying CR, made from layers of metal, very strong seal and are apparently reusable. £100 for the pair. I can vouch for them, but the surfaces of block/head have to be of a good [smooth] finish, dry with no sealing compounds used. I went for these over copper and 'o' rings after recommendation on here from someone.
Lots of manafacturers using this style of gasket since the nineties and Macdeb is spot on they don't tolerate imperfections etc unlike regular composite style, 1990 Honda Accord's was the 1st time I see use this style because the top of the plastic rad would fail causing overheating followed by HGF (no fault of the gasket) they are more tolerent to higher cylinder pressures etc.Edited by macdeb on Friday 5th December 21:36
db484bhpv8 said:
phazed said:
The poor little 4.6, it had such an easy life with me!
How much more porting can you do on the trumpet base/inlet?
I dont think my inlet will be anywhere near yours Peter.How much more porting can you do on the trumpet base/inlet?
I just want to spend a few hours opening from the top and tapering right through to the head.
I believe there is a few bhp lurking for free there still.
Sardonicus said:
more tolerent to higher cylinder pressures etc.
This is my main concern.On the CR front I took 40 thou (which happens to be what Performance Unlimited had in stock so no 4-5 week lead time). 40 thou is 1mm as opposed to 1.2 for the composites so a marginal increase in CR and squish. I run 4.0 pistons in my tophatted 4.6 and have taken a little from the combustion chambers so estimate my CR juat over 10:1. I didnt want to reduce the comp as i enjoy fairly good performance NA and dont want that compromised.
I am confident with some more retard in the nitrous map i can run a 200 shot next season and with better launches from the start line can achieve mid 10's @ 130ish.
Just hope the fairly standard T5 can cope another year of abuse.
db484bhpv8 said:
This is my main concern.
On the CR front I took 40 thou (which happens to be what Performance Unlimited had in stock so no 4-5 week lead time). 40 thou is 1mm as opposed to 1.2 for the composites so a marginal increase in CR and squish. I run 4.0 pistons in my tophatted 4.6 and have taken a little from the combustion chambers so estimate my CR juat over 10:1. I didnt want to reduce the comp as i enjoy fairly good performance NA and dont want that compromised.
I am confident with some more retard in the nitrous map i can run a 200 shot next season and with better launches from the start line can achieve mid 10's @ 130ish.
Just hope the fairly standard T5 can cope another year of abuse.
That shouldn't be cause for concern Derek ....... but you have a small hike in CR now and your also putting your valves nearer those uncut pistons IIRC On the CR front I took 40 thou (which happens to be what Performance Unlimited had in stock so no 4-5 week lead time). 40 thou is 1mm as opposed to 1.2 for the composites so a marginal increase in CR and squish. I run 4.0 pistons in my tophatted 4.6 and have taken a little from the combustion chambers so estimate my CR juat over 10:1. I didnt want to reduce the comp as i enjoy fairly good performance NA and dont want that compromised.
I am confident with some more retard in the nitrous map i can run a 200 shot next season and with better launches from the start line can achieve mid 10's @ 130ish.
Just hope the fairly standard T5 can cope another year of abuse.
worth checking mate 
I am going to do a rough calc on your lump I reckon your around 10.4 CR and you will be at 10.72 with those HG's the stock OE Elring gaskets I have at 100k measured at 1.28mm (every little matters) and with my guesstimate at your pistons down the bore (probably a tad out) at TDC so I cant be certain with those figures but the factor of 0.32 CR increase will be from your Cometics 1.0 versus 1.28 Elrings EDITED to say im at work waiting for my 1st customer so am bored
lazy beggars 
Edited by Sardonicus on Saturday 6th December 09:53
Sardonicus said:
hat shouldn't be cause for concern Derek ....... but you have a small hike in CR now and your also putting your valves nearer those uncut pistons IIRC worth checking mate I am going to do a rough calc on your lump I reckon your around 10.4 CR and you will be at 10.72 with those HG's the stock OE Elring gaskets I have at 100k measured at 1.28mm (every little matters) and with my guesstimate at your pistons down the bore (probably a tad out) at TDC so I cant be certain with those figures but the factor of 0.32 CR increase will be from your Cometics 1.0 versus 1.28 Elrings
EDITED to say im at work waiting for my 1st customer so am bored lazy beggars
A couple of my combustion chambers had some damage so i polished them out and took the same amount out of the others for balance. Debateable i know but i also took out the 'bump' so i may of lost a cc or so there. If you have some more free time... what would an extra cc take the CR down to from your previous guesstimate?
Also to add... when i had my block top hatted the decks were only in need of a clean up so my pistons sit down the bore as standard Landrover tolerance
worth checking mate I am going to do a rough calc on your lump I reckon your around 10.4 CR and you will be at 10.72 with those HG's the stock OE Elring gaskets I have at 100k measured at 1.28mm (every little matters) and with my guesstimate at your pistons down the bore (probably a tad out) at TDC so I cant be certain with those figures but the factor of 0.32 CR increase will be from your Cometics 1.0 versus 1.28 Elrings EDITED to say im at work waiting for my 1st customer so am bored
lazy beggars A couple of my combustion chambers had some damage so i polished them out and took the same amount out of the others for balance. Debateable i know but i also took out the 'bump' so i may of lost a cc or so there. If you have some more free time... what would an extra cc take the CR down to from your previous guesstimate?
Also to add... when i had my block top hatted the decks were only in need of a clean up so my pistons sit down the bore as standard Landrover tolerance
Edited by Sardonicus on Saturday 6th December 09:53
OK Derek maybe 10.3 now after Cometics 10.62 please bare in mind this is all guesstimate stuff with out CC'ing your block and pistons and head chamber vol for instance when you factor in those Elring HG's for calcs the bore/fire ring internal diameter size is not 94 like you could assume but 95.8 its all silly things like this however small 
but I still reckon a lot of the RV8 boys are not running the CR they thought they was promised but lower I always think of CR as extra punch so long as you dont take the piss 
for instance when you factor in those Elring HG's for calcs the bore/fire ring internal diameter size is not 94 like you could assume but 95.8 its all silly things like this however small but I still reckon a lot of the RV8 boys are not running the CR they thought they was I always think of CR as extra punch so long as you dont take the piss Edited by Sardonicus on Saturday 6th December 10:29
db484bhpv8 said:
OleVix said:
What flywheel do you have DB?
Standard 450. It got ripped up somewhat by a paddle plate so i had it skimmed. They also took about 1.5 Kg out the back.http://www.v8tuner.co.uk/category.php?id=20
OleVix said:
Get a light one then! Has a big impact on acceleration...
http://www.v8tuner.co.uk/category.php?id=20
Mine is fairly light. http://www.v8tuner.co.uk/category.php?id=20
I dont seem to have a problem with acceleration but always welcome some more.
0-60 in 3.0, 0-100 in a whisker under 7.0, 0-130 in 11
Sardonicus said:
OK Derek maybe 10.3 now after Cometics 10.62 please bare in mind this is all guesstimate stuff with out CC'ing your block and pistons and head chamber vol for instance when you factor in those Elring HG's for calcs the bore/fire ring internal diameter size is not 94 like you could assume but 95.8 its all silly things like this however small but I still reckon a lot of the RV8 boys are not running the CR they thought they was promised but lower I always think of CR as extra punch so long as you dont take the piss
Will do a dry build and turn it by hand. Plasticine on a piston top? for instance when you factor in those Elring HG's for calcs the bore/fire ring internal diameter size is not 94 like you could assume but 95.8 its all silly things like this however small but I still reckon a lot of the RV8 boys are not running the CR they thought they was I always think of CR as extra punch so long as you dont take the piss Edited by Sardonicus on Saturday 6th December 10:29
Sure it will be fine. Only have a mild Real Steel Typhoon cam with 0.48" lift.
I don't know much about nitrous, other than it has a nice cooling effect .. but as you're effectively increasing the charge density (like supercharging) does nitrous in fact work better the lower you have your compression pressures.?
I.E. in supercharging you can run more boost (charge density) on a lower compression hence more power. I've never really had anything to do with nitrous so don't understand the balance of compression versus allowable nitrous injected so the correlation probably isn't like it is for supercharging .. but are you going the wrong way by increasing your compression if you want more power (more nitrous and fuel) ?
Would love to know how it al works!
Well done so far
great efforts on the strip 
I.E. in supercharging you can run more boost (charge density) on a lower compression hence more power. I've never really had anything to do with nitrous so don't understand the balance of compression versus allowable nitrous injected so the correlation probably isn't like it is for supercharging .. but are you going the wrong way by increasing your compression if you want more power (more nitrous and fuel) ?
Would love to know how it al works!
Well done so far
great efforts on the strip spitfire4v8 said:
I don't know much about nitrous, other than it has a nice cooling effect .. but as you're effectively increasing the charge density (like supercharging) does nitrous in fact work better the lower you have your compression pressures.?
I.E. in supercharging you can run more boost (charge density) on a lower compression hence more power. I've never really had anything to do with nitrous so don't understand the balance of compression versus allowable nitrous injected so the correlation probably isn't like it is for supercharging .. but are you going the wrong way by increasing your compression if you want more power (more nitrous and fuel) ?
Would love to know how it al works!
Well done so far great efforts on the strip
Yes you are right. A common term for nitrous is 'chemical supercharging'.I.E. in supercharging you can run more boost (charge density) on a lower compression hence more power. I've never really had anything to do with nitrous so don't understand the balance of compression versus allowable nitrous injected so the correlation probably isn't like it is for supercharging .. but are you going the wrong way by increasing your compression if you want more power (more nitrous and fuel) ?
Would love to know how it al works!
Well done so far
great efforts on the strip I am wanting a little more from my engine NA and will 'only' be pushing nitrous upto about 200 bhp.
I dont really need much more power to achieve my goal of a mid 10. The gains will come from being able to launch harder on aftermarket driveshafts. Hopefulli i will be able to tune in some nitrous at the launch. Previously i only 'blip' the nitrous system as i hit full throttle for a split second in 1st gear.
db484bhpv8 said:
Yes you are right. A common term for nitrous is 'chemical supercharging'.
I am wanting a little more from my engine NA and will 'only' be pushing nitrous upto about 200 bhp.
I dont really need much more power to achieve my goal of a mid 10. The gains will come from being able to launch harder on aftermarket driveshafts. Hopefulli i will be able to tune in some nitrous at the launch. Previously i only 'blip' the nitrous system as i hit full throttle for a split second in 1st gear.
My bro-in-law won the street racer championships many moons ago using a stock Olds with a stump puller Comp Cam 455 BB with a 8.1 CR and lots of NOS that was a bullet proof combo and proved the most reliable set-up even when compared to the BB Ford and he could dial his times in constantly even without a Tach I am wanting a little more from my engine NA and will 'only' be pushing nitrous upto about 200 bhp.
I dont really need much more power to achieve my goal of a mid 10. The gains will come from being able to launch harder on aftermarket driveshafts. Hopefulli i will be able to tune in some nitrous at the launch. Previously i only 'blip' the nitrous system as i hit full throttle for a split second in 1st gear.
yep lower the CR higher the higher the buffer with NOS 
I know Derek knows this already 
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