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JH Race Car  Rating:  Rating
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 Posted: 10-03-2006 07:15 pm
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Judson Manning
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For those of you racing along with us vicariously, I've attached photos of Ron Earp's car with the new Engine.  Can I tell you how much fun I've been having breaking-in the engine on the streets of Atlanta???

Attachment: RonCar480.jpg (Downloaded 4127 times)

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 Posted: 10-03-2006 07:15 pm
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Judson Manning
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Engine Pic

Attachment: RonEngine480.jpg (Downloaded 4121 times)

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 Posted: 10-03-2006 07:16 pm
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Judson Manning
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Oil Cooler Plumbing

Attachment: RonOilCooler480.jpg (Downloaded 4116 times)

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 Posted: 10-03-2006 07:18 pm
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Judson Manning
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New Engine Oil lines.  Notice the 8AN Accusump line just barely clears the two 10AN oil return and supply lines by about 1/8".

Attachment: RonPlumbing480.jpg (Downloaded 4112 times)

Last edited on 10-03-2006 07:20 pm by Judson Manning

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 Posted: 10-04-2006 12:25 am
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Ron Earp
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Third time has to be the charm, right?

Thanks to Judson for putting in the time on the motor and doing a second one for me. The first one was great, but, I ruined it as detailed in this thread:

http://www.jensenhealey.com/forums/view_topic.php?id=234&forum_id=10

This one will be well taken care of, well, as well as one can take care of a race motor, and will hopfully get us through two seasons. Judson put a lot of attention to detail into the motor and I think it shows. He's built the motor, installed it, and broke it in - you can't ask for more from your engine builder, many thanks!!!!!! If you want one of these little motors done right I highly recommend his services, and he gives advice for free!

We're headed to Atlanta this weekend to pick her up, then we'll bring her back for some more twiddling with a few areas that need attention. I'd love to race her at VIR Goblins Go in October, but, we've got five Spec Miatas entered in the 13 Hour Enduro the week after that race and need to shake them down for renters. Soooooo, the JH won't make a debut race until Feb at CMP in South Carolina.

We do have a roundy round track rented (tentatively) at Burlington NC in December for four hours to dial in brake bias, and just check general running of the car. Not our kind of racing, but it'll do for a shake down track to make sure it'll run at high speed for long lengths of time. Might be cold though......

So, new fuel cell, new catch can for oil, fabricate a spolier/splitter, new graphics, and a few other items and we'll be on track!

Ron

Last edited on 10-04-2006 01:53 am by Ron Earp

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 Posted: 10-05-2006 01:32 am
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Sander
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Is a screw missing from the left carb top?

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 Posted: 10-05-2006 02:12 am
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Judson Manning
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Sander,

We all KNOW I've got more than ONE screw loose!

Judson

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 Posted: 10-05-2006 04:20 am
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Mark Rosenbaum
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Sander wrote: Is a screw missing from the left carb top?

Certainly looks that way.  It also appears that the carb tops are rotated counterclockwise from the proper orientation by 90°.  This might alter the transient fuel/air mix a bit, and I've always considered it an indicator that the person who assembled the carbs didn't quite understand what they were doing.  On the other hand, the Huffaker race cars rotated the tops of their highly modified carbs by 180°, so maybe it's all a Super Secret Racer Trick TM that we're not supposed to notice.

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 Posted: 10-05-2006 01:28 pm
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Judson Manning
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Glad to see everyone has an eye for detail!

We've actually been having a hard time getting the carb mixtures balanced.  That pic was taken on I believe round 87 of adjustments. 

I welded Two EGT probes into header tubes #1 and #4 to help us get it right.  The fun part has been repeatedly taking the carbs apart, checking, re-checking, fiddling, driving, fiddling some more,  so on and so forth.  The only way to test each change is under sustained load, consequently, it's a very time consuming process.

All part of the reason why I insist on test-driving every engine.  We'd hate to see a brand new engine detonate due to something relatively simple.

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 Posted: 10-05-2006 09:31 pm
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Ron Earp
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Mark Rosenbaum wrote:  I've always considered it an indicator that the person who assembled the carbs didn't quite understand what they were doing.  On the other hand, the Huffaker race cars rotated the tops of their highly modified carbs by 180°, so maybe it's all a Super Secret Racer Trick TM that we're not supposed to notice.

I'm definitely guilty of not knowing what I am doing, but I can't see how the top orientation makes any difference. The top just has the bore the plunger rides in. What is important is the orientation of the slide piston and diaphram, but, that is independent of the top.  There is a bleed channel, but the hole is just open to the top of the diaphram and it makes no difference if it is at 12 3 6 or 9 o'clock.

R

Last edited on 10-05-2006 09:54 pm by Ron Earp

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 Posted: 10-05-2006 09:35 pm
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Judson Manning
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Shhhhh!!!!!! Ron

Don't let everyone know our secret!  I'd rather everyone think we're a bunch of amatures.

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 Posted: 10-05-2006 09:56 pm
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Ron Earp
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It is a Super Secret Racer TrickTM then.

Hell, if anyone doesn't know I'm an amateur racer by watching all my mistakes by now then they aren't paying attention! No matter, we press on we'll get there this season!


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 Posted: 10-08-2006 05:29 pm
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Ron Earp
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Jeff and I made the journey to Atlanta to pick up the Jensen with new motor from Judson Manning, our Lotus 907 engine guru. Judson rebuilt the motor after I did bad things to it outlined here:

http://www.jensenhealey.com/forums/view_topic.php?id=234&forum_id=10

Judson put this motor together and fixed a few of the issues with oiling, adapters, lines, etc. that caused the last failure. I think we'll be in business this time around, at least as far as the motor is concerned.

We were able to use Judson's GA tag from his road going Jensen to have a few spins around the block in the race car. In fact, I have some rather crude video of Jeff driving as well as some pictures I'll download off the camera and post.

Anyhow, with a street muffler setup the car drove very well! Motor was smooth, as smooth as a 907 is going to be.  Power is good I think. Pulls decently to about 4k, and then pulls really strongly from about 4.5k to around 6.5k-7k, at least strong for a 4V 2L.

We were able to run it back to back against Judson's 2.2L car with Delortos and Supra 5 speed (which is an EXCELLENT modification) and it was really interesting.  Judson's motor definitely has more poke in the 3k-4.5k range or so, but from about 4 to 4.5k on up to red line both cars behave identically, which is a very nice suprise considering all the press the 2.2L cars get.

Judson feels in this RPM range the head is limited and I agree with him, although our minor port work on the race motor might have allowed us to equal the larger displacement 2.2L. Anyhow, they both drove very nicely and I'd prefer a 2.2L except for those pesky rules....but a well assembled 2L with Strombergs can get the job done.

We've got more work to do though. We feel we'll pick up some more power on the race motor as we've not optimized timing and A/F on the dyno and we're running a street muffler. Carbs need to be gone through carefully (but we're keeping the Super Secret Racer ModTM) with everything setup just so.  We really don't know much about the dizzy advance curve and our initial timing is set at a conservative 10 degrees, so, there is some power there unless we're just lucky out of the box.

From our exhaust gas probes fitted on #1 and #3 we know that we're running a tad to rich, which also hurts power a little. Work on these a little bit and see what can be done here.  All work for the coming months!

Judson has built a very good motor and I'm very encouraged by what we've seen so far. My race partner Jeff was really excited about the power as we're been concerned that the car might not hold its own in ITS given some of the other iron in the class. I think if we can eek out a little more juice from it we'll be good to go.-

Anyhow, it has been a long road on this car, very long indeed. Jeff Young has put in countless hours on this car and I really appreciate his time and effort, it is as much his car as it is mine and we hope to run The Jensen and the TR8 in ITS for 2007. A British Attack!! Judson has done a fantastic job on the motors (two motors) and we're looking forward to flogging his engine around on the track to see how it works out.

Here are some really bad camera phone photos and video:




http://www.gt40s.com/images/jh.3gp

Video will work in QuickTime.

Ron

------------

Last edited on 10-08-2006 06:11 pm by Ron Earp

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