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1980 Aston Martin Bulldog (a Challenge if you will)

PostPosted: Sat Apr 06, 2013 3:33 am
by Juno8
Could I ask someone to take a look at this engine please I am trying to make an Aston Martin Bulldog engine work and I just cannot get the turbochargers or the power in the right place could someone take a look into it and I am going to give you the page that I am using for the engine statistics also

can anyone help me out????
I am asking for a heck of a lot out of you I will do a video on this when its fixed call that a big prize for you :) (Absolution this is a challenge worthy for you)

Page:
http://www.carfolio.com/specifications/ ... ?car=22660



Your challenges if you are willing to accept are:
(The Problems
What I am expecting to see I hope)

Max power of 600bhp (447.4 kW) at 6600rpm
Power must be 600bhp (447.4 kW) at 6000rpm

Max Torque of 500ft-lbs (678 Nm) at 4300rpm
Torque must be 500ft-lbs (678 Nm) at 5000rpm

Turbo chargers are not at the right rpms
Turbo must come in at 4500rpm from what I have read on different forums

Valve Float
This has to be sorted out and corrected

Emissions of 1112
Emissions must be to 1980 Standards

Economy is horrific
As good as you can get it

Lifespan is 36000km
Anything greater than 40,000km+

Re: 1980 Aston Martin Bulldog (a Challenge if you will)

PostPosted: Sun Apr 07, 2013 12:41 pm
by oldgreg
Here's something that I think is reasonably close.

Re: 1980 Aston Martin Bulldog (a Challenge if you will)

PostPosted: Sun Apr 07, 2013 12:56 pm
by Juno8
as close as you can will be good enough is there any way of strangling something more out of it or is that it?

Re: 1980 Aston Martin Bulldog (a Challenge if you will)

PostPosted: Sun Apr 07, 2013 1:06 pm
by Juno8
Give me credit I chose a very tricky engine to make

Re: 1980 Aston Martin Bulldog (a Challenge if you will)

PostPosted: Sun Apr 07, 2013 1:23 pm
by oldgreg
Juno8 wrote:as close as you can will be good enough is there any way of strangling something more out of it or is that it?


Maybe, but that's as close as I feel like I'll be getting it any time soon. Someone else is welcome to take a crack at it though.

Re: 1980 Aston Martin Bulldog (a Challenge if you will)

PostPosted: Sun Apr 07, 2013 1:25 pm
by Juno8
yeah its a pig of an engine to get right I just wish Car Folio had a way of showing Air Fuel and Ignition timing as well that would be a great help as well as Cam Profile!

Re: 1980 Aston Martin Bulldog (a Challenge if you will)

PostPosted: Mon Apr 08, 2013 11:59 pm
by Juno8
oldgreg here is your prize I did a bit of a run through of my pathetic attempt at this engine but then I did the rest of the video on your engine :D

let me fix the error I will post it up tonight give me time

Re: 1980 Aston Martin Bulldog (a Challenge if you will)

PostPosted: Tue Apr 09, 2013 5:21 am
by oldgreg
Uhh, that's not my engine.

Re: 1980 Aston Martin Bulldog (a Challenge if you will)

PostPosted: Tue Apr 09, 2013 5:24 am
by Juno8
oh F-beep-....give me a few hours please...

Re: 1980 Aston Martin Bulldog (a Challenge if you will)

PostPosted: Tue Apr 09, 2013 10:45 am
by xABSOLUTIONx
this is as close as i can get on power, have no idea on how to drop torque or get rid of valve float, presumably only by adding more valves or making smaller bore

anyway, i don't really understand engineers, why make it DOHC if it only has 2 valves per cyl? :geek:

Re: 1980 Aston Martin Bulldog (a Challenge if you will)

PostPosted: Tue Apr 09, 2013 11:05 am
by Juno8
yeah WTF mate and I will do a video on this but I will censor it because its youtube mate

Re: 1980 Aston Martin Bulldog (a Challenge if you will)

PostPosted: Tue Apr 09, 2013 12:19 pm
by oldgreg
xABSOLUTIONx wrote:this is as close as i can get on power, have no idea on how to drop torque or get rid of valve float, presumably only by adding more valves or making smaller bore

anyway, i don't really understand engineers, why make it DOHC if it only has 2 valves per cyl? :geek:


All that's needed to fix the valve float is to add a little quality to the top end, as the valves are apparently only just starting to float. And as for the torque I found that increasing cam and ignition increased torque more at peak power rpm than at peak torque rpm, and that by lowering boost pressure at the same time I could limit peak torque but keep the torque curve flattish enough to still make the requisite 600hp.

As for 2 valve DOHC, there would be a few benefits over 2V OHC or SOHC. The biggest would probably be the ability to use a pent-roof combustion chamber by having the valves at an angle to each other which I think would be impossible with OHC. And by not having the intake and exhaust ports quite as close to each other there should be a reduction in intake air temperatures (and consequently an increase in VE) over OHC. And you wouldn't have the added friction/inertia/complexity of SOHC rocker arms. And it seems like you'd get better scavenging than with OHC as well.