jeffw
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| posted on 25/4/10 at 10:26 AM |
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Zetec
Right, after the demise of the Silvertop yesterday I have to choose a replacement. The car is/was running Jenvey ITB, Piper 285 cams + Vernier
pullies with a Megasquirt MS1 V3 and making around 185BHP. It has a Raceline sump and alternator kit. I would have thought the cams are wrecked as
the engine is completely out of oil and is seized.
The simple thing to do would be to replace it with another Silvertop as everything will fit. So 2nd Silvertop + new cams = 185BHP.
Or go for a Blacktop + cams to make around 195BHP (blacktop is meant to be 10BHP better than a silvertop)
Or......get a ST170 engine with its stronger bottom end and very good head. With cams around 210BHP ???? Does the VVT operate on aftermarket cams
and if so how would you trigger the change over from a Megasquirt.
Ideas or thoughts ?????
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RichardK
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| posted on 25/4/10 at 10:29 AM |
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I believe that Coozer has this worked out, so maybe worth a quick u2u if he doesn't reply.
Cheers
Rich
Gallery updated 11/01/2011
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will121
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| posted on 25/4/10 at 11:01 AM |
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dont know how VVT works with performance cams but think shift light output can be used to trigger the VVT as a single action eg on/off but not
proportional. think later MS has specific output for it
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sebastiaan
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| posted on 25/4/10 at 11:14 AM |
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Keep in mind the ST170 engine is a bit higher compared to silver / blacktop zetecs and you might end up with the VVT solenoid sticking through the
bonnet.
MS1 extra can control the VVT based on RPM (or any other parameter; I use it on my Indy to transfer from launch control mode to "normal"
at 10mph)
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MikeRJ
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| posted on 25/4/10 at 11:34 AM |
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quote:
Originally posted by sebastiaan
MS1 extra can control the VVT based on RPM (or any other parameter; I use it on my Indy to transfer from launch control mode to "normal"
at 10mph)
Only in an on/off mode as will says. The original ST170 system varies the timing continuously.
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sebastiaan
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| posted on 25/4/10 at 11:46 AM |
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Yes, very true. Don't know if any version of MS does continuously variable cam control, as it would require mac and crank position sensors.
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jeffw
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| posted on 25/4/10 at 12:36 PM |
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What power difference is there between the Blacktop & ST170?
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MikeRJ
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| posted on 25/4/10 at 01:34 PM |
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quote:
Originally posted by jeffw
What power difference is there between the Blacktop & ST170?
About 40bhp in standard form, the ST170 is around 170bhp.
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jeffw
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| posted on 25/4/10 at 01:41 PM |
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Pretty sure they would be closer than that with both on cams & Jenveys?
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coozer
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| posted on 25/4/10 at 02:45 PM |
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Some peeps still don't get it do they??
My VVT comes on after 3K rpm AND above 25% throttle. Thats how I have it set in my MSv2.1.
The timing is varied by the oil pressure and makes no difference in our cars.
With the VVT solenoid 'off' the oil is routed to the front of the cam where there is a helical gear and pushes the cam to full retarted...
(emmision control and smooth idle), when the solenoid is given 12v it moves up and transfers the oil behind the helical gear and advances the cam
forward, as long as your in the 'on' part of the fuel map it varies by the oil pressure varying.
Totally different to either the rover VVT (electronic) or the SE zetec engine.
Basically the way I have it setup means its in the retarded position when cruising, saving fuel and when I floor it it kicks in and goes
ballistic
Go for it, is really that simple, no matter what other peeps will have u think.
1972 V8 Jago
1980 Z750
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