Lotus Elan

Stromberg 175 CD-2 B1BT/B2AR Adj Needles to Enlightenment

PostPost by: bdea » Fri May 29, 2020 3:42 pm

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Could I please ask for a favor from the Lotus Elan.net Forum members?

Does anyone have pairs of B1BT and/or B2AR Adjustable Needles that I could borrow to test against my current installed B1CE adjustables?

My current needles are B1CE that are filed down to 50% diameter at positions 7-13.

The current setup was done when I dynoed my defederalised 1969 SE4 Coupe.

The modifications at that time was the removal of all the emissions equipment, capping off butterfly shafts and emission ports and the replacement of the Distributor to 43D.

The Stock motor was modified when Dynoed by Charlie Rockwell in 1990 and has traveled 22k miles since.
It has slept for 7 years after I retired and was motivated to awaken via my good friend Mike Ostrov of Elite fame! We have been trying to resolve a bogging off the line issue ever since it was dynoed in 1990.

Here are some of the specifics of my Build and dilemmas:

Original Setup:
Stock 0.40 over motor
Balanced (no sizzle at directly connected lever w/o rubber bush)
Dave Bean modified head to Big Valve Head Specs w slight porting, blunted nosed siamesed intake tracts
Pertronix Ignitor w MSD 6A Multi Spark Ignition, love that staccato sound! in a 43D Distributor w Blaster coil
Now: Pertronix III auto dwell w rev limiter set at 6.2k rpm, SHOULD I RAISE IT TO ? Max RPM?
Stromberg 175 CD 2S ( Jaguar XJ 1971-2 ) with filed down B1CE that are filed down to 50% diameter at positions 7-13
SS header with Sprint Muffler that I carried on the plane in 1985!

115 HP at the flywheel and 100 at the wheels.

Tried B2AR needles at the time but too rich at part throttle and too lean at Full throttle. Opposite of what you want! Filed B1CE needles!

Ignition Timing: 15 degrees BTDC, 30 degrees max at 5-5.5k rpm. Not sure which Distributor was used at that time:
25D, max to 30 total advance at 5.5k rpm, 15 degrees static or
new 43D to 25-27 max at 3k rpm, 10 degrees Static

Cam timing: Exhaust 108.5 degrees BTDC, Intake 111 ATDC

No test for detonation

Current Issues:

Bogging at start off, have to rev off 975 rpm idle to 1.2k rpm to prevent stumble! Bucks every Time!
Idle was erratic, held steady then dropped 100 rpm and go back up by itself! Could be additive fouled spark plugs!

Corrections with Mike:
Balanced Carbs, Vacuum steady at 19, spark energy at high tension wires at 5k volts
Cleaned spark plugs NGK BPR6ES of Current Premium Costco California Gas additive build up, look at pics!
Resistive NGK ignition spark plug wires checked for spark voltage = 5K volts
Timing at 10 degrees BTDC w 25-27 total Advance
Car runs better, but still looking the ultimate performance!

Thanks to you All! :mrgreen:

Brad Dea

PS: I will be attending the San Francisco Bay Area GGLC Meet BBQ / Parts Swap Meet at Mike Ostrov's Shop in El Sobrante, CA. Saturday June 14,2020 to swap stories and possibly help others in our pursuit of Lotus evana? Nirvana :oops:
Spent last 4 hours editing after loosing the post on the cell phone and half asleep!
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Last edited by bdea on Sat May 30, 2020 3:36 am, edited 3 times in total.
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Location: SF Bay Area

PostPost by: bdea » Fri May 29, 2020 3:52 pm

Also review my other post on Bog and Hesitation:

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