Engine capacity question

[240z]

In terms of capacity and output, you might be interested in Ben's car in Aus, he was the person that put together my car.

http://www.viczcar.com/forum/index.php/topic,2043.0.html

it shows the time, effort and money involved, and I think steve played part too...

 

[SKiddell]

Is the sequential shifter like the one I posted about on here a while back?

yep sure is...(when you posted it I thought "no don't tell anyone" they'll all want one)

240z Phil
270 hp is nice but the torque is a little low.....mind you a compression ratio of 10.5:1 would account for it
Beautiful car though

 

[SKiddell]

Is the sequential shifter like the one I posted about on here a while back?

yep sure is...(when you posted it I thought "no don't tell anyone" they'll all want one)

240z Phil
Beautiful car
270 hp is nice but the torque is a little low.....mind you, a compression ratio of 10.5:1 would account for it.

 

[Charlie Boy]

Ben has standard size valves you really need to go for 46mm inlet and 38mm exhaust valves and a lumpy cam to get the most from the 3.1L

 

[twoforty]

yep sure is...(when you posted it I thought "no don't tell anyone" they'll all want one).

Not at that price they won't!

 

[SKiddell]

Ben has standard size valves you really need to go for 46mm inlet and 38mm exhaust valves and a lumpy cam to get the most from the 3.1L

Too a point but surely 10:5:1 isnt going to get the best out of an NA engine no matter what valves are used....torque is a direct correlation to cylinder pressure and cylinder pressure is a direct result of dynamic compression, and the cam has a massive bearing on dynamic compression so if the static compression isnt high enough in the first place then adding a big cam is only going to reduce the DCR futher for example a big lift long duration cam (valve closing latter and later in the cycle) can typically reduce dynamic compression by up to 3 or four points from the static compression figures and the general concensus is that a dynamic compression ratio in the range of 8.5:1 is achievable with good fuel so 10.5 - 3 = a dynamic compression of 7.5...room for improvement surely. I've run CR's of 11:1+ on forecourt fuel with no issues and comfortably got 250Hp out of a 2.8 litre with 212 ft/lbs of torque....take a look at Ben Stapleys numbers (270 ft/lbs at 4k) if you want good torque figures for a stroker

Just my 2p's worth as usual

 

[Charlie Boy]

Too a point but surely 10:5:1 isnt going to get the best out of an NA engine no matter what valves are used....torque is a direct correlation to cylinder pressure and cylinder pressure is a direct result of dynamic compression, and the cam has a massive bearing on dynamic compression so if the static compression isnt high enough in the first place then adding a big cam is only going to reduce the DCR futher for example a big lift long duration cam (valve closing latter and later in the cycle) can typically reduce dynamic compression by up to 3 or four points from the static compression figures and the general concensus is that a dynamic compression ratio in the range of 8.5:1 is achievable with good fuel so 10.5 - 3 = a dynamic compression of 7.5...room for improvement surely. I've run CR's of 11:1+ on forecourt fuel with no issues and comfortably got 250Hp out of a 2.8 litre with 212 ft/lbs of torque....take a look at Ben Stapleys numbers (270 ft/lbs at 4k) if you want good torque figures for a stroker

Just my 2p's worth as usual

My engine is being assembled as we speak and I have gone for the 46In/38Ex mm valves with 11.20:1 compression with 300 duration and 560 lift cam, flycut pistons etc etc. I could have gone for over 600 lift a lower duration but thought I would try this first and see how I go. Fingers crossed it should be a good road and track engine if there is such a thing

C

 

[SKiddell]

My engine is being assembled as we speak and I have gone for the 46In/38Ex mm valves with 11.20:1 compression with 300 duration and 560 lift cam, flycut pistons etc etc. I could have gone for over 600 lift a lower duration but thought I would try this first and see how I go. Fingers crossed it should be a good road and track engine if there is such a thing

Now that sounds nice ....would really like to see some dyno pulls of that one Charlie boy
What exhaust combination (header etc) will you be using

BTW where are you based

 

[Charlie Boy]

Now that sounds nice ....would really like to see some dyno pulls of that one Charlie boy
What exhaust combination (header etc) will you be using

BTW where are you based

At the moment I have a Trust exhaust manifold which is actually the weakest link in my setup as it only has 42mm primaries and seeing as the exhaust ports have been substantially increased in size I might go for a YS Garage manifold from Japan. Depending on which manifold I end up with the plan is to run 2x2inch stainless pipes to a merge collector half way along the transmission tunnel which will then go into 3inch pipe and magnaflow mufflers. As for the intake manifold that has been ported to the enlarged head ports with 50mm Solex carbs.

Yeh I’m looking forward to some dyno pulls too, good things come to those that wait as they say

I was based in Melbourne OZ for two years now I’m back in the UK and hopefully will be shipping both my Z’s back around Christmas time.

I’ll try to post some pictures of the head if I can figure out how to post them up, but maybe a bit of a thread high jack

 

[Charlie Boy]

I’ll try to post some pictures of the head if I can figure out how to post them up, but maybe a bit of a thread high jack

Not sure if this will work

 

[Charlie Boy]

Some more

Two pictures of my not quite finished standard car as well.

Come on Rob you know you want a stroker

C

 

[SKiddell]

but maybe a bit of a thread high jack

I'm sure Rob wont mind

and seeing as the exhaust ports have been substantially increased in size

carefull not to lose to much gas speed, still with the big valves, lovely porting work and good displacement scavenging should be good.

Sweet head pictures, who's done the work, what cc are the chambers (38 cc?)...any flow bench numbers, who's the cam done by, what lb seat pressure springs are you using, any pictures of the pistons (valve reliefs).....so many questions.

BTW seeing as you are back in the UK, when you get the cars back if you ever want to sell the trust header keep me in mind, 42 mm primaries are great for good scavenging on the smaller capacity units (2.4, 2.6, 2.8)

Could do with PMing you but cant until your a member

 

[vpulsar]

I'm sure Rob wont mind

I don't mind at all , All debate and sharing of info is always a good thing.

I'm trying to weigh up the options at the moment, I do like the look of the standard engine layout, But from looking at all the info on the site it can and is a very costly exercise to build a really nice strong and reliable 6 pot, Apposed to buying a brand new small block crate engine and t56 transmission from the states.

After spending the last seven years building my very highly strung 500 bhp pulsar, I can tell you I'm defiantly liking the easy option .

Anyway sorry for spamming up your thread .



Rob

 

[240z]

yep sure is...(when you posted it I thought "no don't tell anyone" they'll all want one)

240z Phil
270 hp is nice but the torque is a little low.....mind you a compression ratio of 10.5:1 would account for it
Beautiful car though

Is the torque a bit low?

from my basic calculations:

258 hp @ ~5700
~237 ftLb torque
with drivetrain losses (20%?)
~285 ftlb

which if Ben Stapleys figures are from the engine dyno, would seem comparable. I assume the torque figure would also have losses (bhp is a calculation from torque). Do correct me if i'm wrong though, I find this stuff fascinating!

 

[Charlie Boy]

Head was built in Japan Block etc in OZ

Valve Spring set load: appx 50kg
Combustion chamber volume: 39cc
Camshaft: Schneider 300F:
Pistons: Kameari 89mm

No flow numbers

OK will look into becoming a member

Anyway sorry for spamming up your thread .

.
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[SKiddell]

258 hp @ ~5700
~237 ftLb torque
with drivetrain losses (20%?)
~285 ftlb

So your calculations are assuming that the graph is flywheel hp and Ben does say in his posts that the car is making 270 rwhp
In fact he also says
"Took the Zed to WSID today to do some quarter mile runs. The best was a 13.66 at 102.2mph"

Doesnt add up, ET is sometimes confusing but terminal speed NEVER lies, both John and I have surpassed this by over 2 miles per hour with heavier cars both of which definitely dont have 270 rwhp.

Still cant take it away from the chap though...its a beautiful, well prepared car...its even got a carbon fibre roof

 

[SKiddell]

[QUOTECharlie boy]Head was built in Japan Block etc in OZ

Valve Spring set load: appx 50kg
Combustion chamber volume: 39cc
Camshaft: Schneider 300F:
Pistons: Kameari 89mm[/QUOTE]

Nice

No flow numbers

shame

OK will look into becoming a member

Do it and come to Santa pod...get into the drag challenge and get your name into the Z clubs Hall Of Fame....probably the largest collection of 1/4 mile performance data ever collected for one marque of car....

 

[Charlie Boy]

Do it and come to Santa pod...get into the drag challenge and get your name into the Z clubs Hall Of Fame....probably the largest collection of 1/4 mile performance data ever collected for one marque of car....

I’m not a big drag fan, well I like to watch it but I just can’t bring myself to repeatedly dump the clutch at 5k. I have a few drag DVD’s that were shot in Japan and their up to 10sec 1/4mile run’s with N/A strokers. Anyway to try and control crank shaft harmonics amongst other things I have gone for a small 225mm 6 puck clutch on Kameari flywheel. If I want to go drag racing I’ll have to go with a heavy flywheel and twin plate clutch and cement in the block

I'm trying to weigh up the options at the moment, I do like the look of the standard engine layout, But from looking at all the info on the site it can and is a very costly exercise to build a really nice strong and reliable 6 pot, Apposed to buying a brand new small block crate engine and t56 transmission from the states.

You could have a big block Chevy 572 with 700bhp for not much more than what I have spent on my engine

C

 

[240z]

So your calculations are assuming that the graph is flywheel hp and Ben does say in his posts that the car is making 270 rwhp

Nope I was assuming the graph was at the wheels, which seemed to have peak torque at 258hp (rear wheel), I guessed was about 5700 rpm, but difficult to tell.. I couldn't work out what measurement the torque, on the right y-axis was in!

I'm not commenting on the E.T. however

 

[vpulsar]

You could have a big block Chevy 572 with 700bhp for not much more than what I have spent on my engine

Well that's exactly my point Charlie , I think the lightweight alloy small block would make a fantastic tool for road/track use .

My Pulsar engine cost me about 12k in total build costs , I could put a small block and box in a 260 for about 7k max I reckon.

Even less if I bought second hand, But I think at $5000 for a brand new crate engine you'd be mad not to, In fact it would almost be rude not to .



Rob