RWD 7AGE (BT 20v Head) Questions

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RWD 7AGE (BT 20v Head) Questions

Postby Lurkin » Sun Mar 25, 2012 11:26 pm

(1) Is it worth/ possible to try and keep vvt?
(2) Are aftermarket rods required for an n/a set up?
(3) Will a 4ac to T-50 bellhousing fit to a 7a block?
(4) is it worth the effort? or should I just revert to buying a BT 20 4age and be done with it? Is anyone willing to provide figures/ dyno sheets of their success?
(5) I have read that 'cutting a new keyway' can solve the requirement of adjustable cam wheels. Can someone explain a little more about what this means?
(6) can this be run [successfully] from BT ecu, or would it run like a sack and require an aftermarket ecu?

Have searched this forum, and several others + google, asking because I have had some mixed answers.
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Postby Bazda » Mon Mar 26, 2012 10:58 am

Thought you would find enough info on the forums.

Keep VVT, why not its there. Not going to make anything harder to install.

Id def use aftermarket rods, we sell them which are custom made for the 7a engines.

Yes T50 bell housing will fit

7a will net you more torque and a little more top end. You will get a heap more mid range as well over the 4a.

We do the crank sprocket key way cutting to bring the engine timing back inline. We just spark erode a new key way position in the sprocket at a certain angle.

I would be running an aftermarket ecu as it will require alot more fuel from low to mid range.
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Postby Lurkin » Mon Mar 26, 2012 10:51 pm

I ask about vvt because the head I purchased doesnot have the vvt cam wheel, nor the solenoid with it- both of which are expensive to replace.

I'm trying to figure out whether its worth the expense of purchasing these parts, or getting aftermatket adjustable cam gears and blanking off vvt. This is not for the rice, because 20v parts rare and expensive in aussie.

From what I've read the only time they are required is to run very large cams ..
Which I'm not planning to do.

I have also read that the relationship between the cams, timing and 7age stroke are not as well matched to keeping vvt. I suspect this is rubbish... but again asking because I am unsure.

Thus I'm trying to confirm whether this is true, I.e. with stock cams it is actually better to have vvt.

Will it actually lose power dropping vvt?
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1993 ae101 gt apex levin (sold)
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Postby Bazda » Tue Mar 27, 2012 8:05 am

Lurkin wrote:I ask about vvt because the head I purchased doesnot have the vvt cam wheel, nor the solenoid with it- both of which are expensive to replace.

I'm trying to figure out whether its worth the expense of purchasing these parts, or getting aftermatket adjustable cam gears and blanking off vvt. This is not for the rice, because 20v parts rare and expensive in aussie.

From what I've read the only time they are required is to run very large cams ..
Which I'm not planning to do.

I have also read that the relationship between the cams, timing and 7age stroke are not as well matched to keeping vvt. I suspect this is rubbish... but again asking because I am unsure.

Thus I'm trying to confirm whether this is true, I.e. with stock cams it is actually better to have vvt.

Will it actually lose power dropping vvt?


Yes you will loose alot of low end to mid range power.
I have dyno plots showing vvt on and vvt off. Over 40kw atw loss at one point.

VVT works with stock cams very well. Also works with aftermarket cams as well. Id always opt to try keep vvt no matter.

The parts are not that expensive.
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Postby ryanfels » Wed Mar 28, 2012 7:46 am

Can you not run a stock ECU at all and just get bigger injectors to suit?
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Postby Lurkin » Sat Mar 31, 2012 2:20 pm

found this on the web:

http://www.speednsound.co.za/forum/view ... 9a33a94b62

The rods had been redrilled to allow for the 4age ARP rod bolts to be used instead.

Has anyone on here tried this?
Pros/ Cons?

I'm pretty tempted to give this a go given this will be a shoe string build?

I'm imagine the stock ecu + larger injectors could work, but it surely it would be hard to match the size of the injector to the amount of fuel required/ regulate it?
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1985 4age aw11 (well crunched)
1993 ae101 gt apex levin (sold)
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