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[1 Svo] Engel 55 cam install and dyno testing
This is a quick message to fill you guys in. I will have much more info
posted to the web in the near future.
Last Saturday, Chris Thomason brought his Merkur XR4ti down to my house for
installation of an Engle TCS-55 cam. That's the one I've been selling and
recommending. Mike Ray shows up with an extra set of hands and we're ready
for testing. We put the car on the DynoJet dyno at WoodBridge DynoTech and
ran a baseline pull. I don't have the sheets here with me, but I believe
it did 215 HP at the rear wheels.
Then we went back to my house and put the cam in, and then broke it in.
Then we went back for the "after" pull. Well we were about 60 hp down from
4000 RPM on up. Arggh! What have we done? We had reconnected the knock
sensor... So, we disconnected it, and made another pull. That was much
better, and resulted in a 5 hp increase from 3000 RPM on up. This proves
the knock sensor is a serious limitation to making HP. Ther's no way the
car was knocking. You can hear really good on the dyno :) The curve was a
mirror of the before run, but just about 5 hp, all over. This is kind of
odd, because most cams will show a change in the power peak. I've decided
that this combo is now flow limited by the intake and exhaust manifolds and
head. Serious porting should be the next move. It also shows that the
stock 5 speed XR cam, which is the same cam as the FMS A-231, and also the
later SVO cam, is a very good match to the flow capabilities of the stock
manifolds and head.
Here's the particulars on the car. 87 Merkur XR4ti, 5 speed, Nick's 3"
exhaust, 86 SVO EEC-IV and VAF, and an intercooler setup made by Chris,
that uses a Thunderbird SuperCoupe IC core and custom mandrel bent tubing.
The wastegate bleed was set for about 16-17 PSI of boost.
Conclusions: For a stock head, the cam only makes a small improvement,
*IF* you already have the XR manual trans cam or the later (85.5-86) SVO
cam. If you have an automatic trans XR or an earlier SVO, then it's a good
move. The 55 supports future improvements to your flow capabilities, which
hopefully we will be proving in the near future, by porting Chris' parts.
Scanned dyno sheets and pictures will be on my web site soon.
BTW, this is the only documented camshaft change dyno results that I am
Irony: God gave the tortise a coeffficient of drag of 0.03