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Thread: SR20VE serious starter kickback issue

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Posts: 1-5 of 5
2017-03-20 07:48:47
#1
SR20VE serious starter kickback issue
Hello,

First of all, this will be a long post, I hope someone has the patience to read it until the end.

I am a very long time follower of this forum and I have learned a lot in here, but I have not posted before.
I live in Ankara, Turkey and I have the one and only 00' Primera P11-144 Hyper CVT M6 with an SR20VE in Turkey.
It took 1,5 years for me to gather all parts and another 6 months to have the job done by the most reputable Nissan shop here in Turkey.

The shop is specialized in building race engines for drag / drift cars and they have a 750 bhp CA18DET in their S13. They have also built many RB26's and 2JZ 's. They are very capable of building turbo engines but this is the first time they have built an all motor SR20VE, since we do not have SR20VE 's here in Turkey. The specs of the engine are listed below :

SR20VE head on EUDM Roller Rocker block
-Lightly skimmed head
-Supertech +1mm intake valves
-Supertech std exhaust valves
-Supertech springs (93 lbs) and retainers
-Kelford 184-D cams (20V/N1 hybrid)
-Tomei Cam gear
-Bosch EV14 550cc injectors
-VAG coil on plug
-SR20VE 20V CAS
-Spark EMS standalone ECU (an ECU designed and built by a Turkish guy and there are a few hundred people using this ECU for their engine builds. As far as I know, the ECU has been derived from a VEMS ECU, the software seems very similar too.)
-MAF Delete / Bosch MAP
-Custom intake manifold + Blitz SUS Power air filter
-75mm RMR throttle body
-Tomei FPR
-SR20VE IACV
-The bottom side is as follows :
-SR20DE 4CW crankshaft
-Manley H-Beam rods
-CP 87mm 12.5:1 pistons
-Mazworx 87,5mm SR20VET headgasket
-Mazworx mechanical timing chain tensioner
-New OEM water pump, oil pump, crank pulley, timing chain and gaskets.
-ASP 4-1 3” header
-Stainless 3” exhaust system with 2 Vibrant Ultra Quiet resonators and 1 Dynomax VT muffler (still very loud)
-PLX Wideband (Bosch 4.9) + EGT
-Speedhut gauges for Water temp, Oil pres. and trans temp.
-Improved Racing oil cooler
-Improved Racing trans cooler with thermostat and fan

I had the engine built about 3 weeks ago and I am still using the CVT transmission and it is not as bad as you think it is. I always have the chance to convert to manual. I may have done 400 - 500 miles since the build and the shop wants me to drive like 1250 - 1500 miles for breaking in the engine. Right now I have igniton cut at 5k rpms and the intake cam engages at 4.5 k for just 500 rpms

Even though everything looks good on paper, the thing is that, I want to pour gas on the car and burn it down to watch it explode into fireballs............because,

The car has very very very serious starter kickback issue. It ate the original starter, a hybrid one with a more powerful motor (2 times) and today, a frankestein one from a 3 liter diesel engine. It broke the bendix 3 times, the reduction gear twice and broke the nose cone once. We have even added a brace to the end of the starter to fasten it to the engine block.

Cylinder compression test was over 300 psi on each cylinder (the gauge only goes to 300 psi) and the first diagnosis was that the original starter cannot cope with the compression since the starter for the CVT motor has lower rpm and less torque than the manual version. The compression shall be a bit higher than 12.5:1 since the head has been lightly skimmed.

When we try to start the car, the engine turns then stops for a second, then keeps on turning, then stops again, and if you are lucky, it starts. It also pops and bangs like crazy (we sometimes have explosions from the intake manifold and exhaust during cranking) Once it starts, it has a smooth (but a bit on the high side like 1200 rpms) idle and runs fine. During cruising, the AFR is between 14.5 - 15. But generally the case is, especially if it is a bit cold outside or if the engine has not been run for more than 12 hours, it does not start, it pops, bangs and breaks the starter because of kickback. The AFR goes lean after a few cranks and I have to step on the gas pedal to get it to start. If I was lucky and could start the engine, I can start it again within a few hours time, before the engine completely cools down, but usually by having to step on the gas pedal.

I run 15 - 20 pct ethanol over 95 octane gas (it translates to 91 octane for US guys) or 97 octane (93 for US) whenever I can find it. If I don't add ethanol, it pings. The timing has been retarted both mechanically and by the ECU and the timing advance has been pulled down to 0 degrees during cranking. I have been told that the ECU has been programmed to crank the engine for 2 full cycles without spark then ignition is activated at the 3rd cycle.

I have read about many many builds on this site and sr20forum but no one has had such problem, so I am not sure what is going on.

I am sure that the guys at the shop did not degree the cams with a degree wheel, but they say that they have triple checked the cam adjustment, and the car does not want to start even if they retard the cams by the cam gear.

The battery is new and has 800 CCA, we have upgraded the cable to the starter with a 0 AWG cable. We have checked the grounds as well.

I am about to lose my mind and I cannot think of a solution. I am very depressed to see that after all that cash and time spent, I am left with a piece of garbage lying in front of the house.

I hope someone can guide me since I am out of ideas...

Thank you in advance.

Can...
2017-03-20 17:41:18
#2
300psi? Wow. That is extremely high. Are you sure the compression ratio isn't higher than you stated?
Has the cam timing been altered any? That can increase or decrease cylinder pressures.
2017-03-20 18:10:59
#3
We did not take measurements during the install but the compression shall be between 12.5:1 and 13:1 tops, since the head is very lightly skimmed.

The lowest cylinder pressure we could achive by fully retarding the cams is 270 psi. We could not go lower...

However, I don't think the cams have been degreed properly. It runs fine when I am able to start the car, but there may be a slight misalignment. Do you think a few degrees of cam misalignment cause too high of cylinder pressure ?
2017-03-20 21:14:29
#4
High compression, and what sounds like the engine is trying to turn backwards.

How much was the head skimmed? Was that taken into account when degreeing the cams?
2017-03-21 02:25:24
#5
No issue with running this compression for a turbo application.

Recently tested similar compression setups on C85 making upwards of 1000whp.

Sounds like an issue with the Cam/Crank reference in relation to a spark event. Can you share the Cam/Crank setup information as displayed in VEMS?

- - - Updated - - -

Would also need to know what you are using for a CAS disk
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