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1987 244 DL Autocrosser

Pulled timing belt and reinstalled to verify correct cam timing and intermediate shaft timing. With #1 at TDC, rotor doesn't point right at #1 on the cap, so I have to look at that and see if something is off or if I compensated for it in MS. When down at ian's not long ago, we set timing to a fixed 15 or 20 deg and checked with the timing light and it read correctly, suggesting trigger angle is correct. But at first glance it looks like the dizzy is off a tooth. :e-shrug:

Checked valve clearances and the 0.002" feeler was tight on all of them, so I pulled the cam and found that rubber valve silencers had been installed. Didn't expect them to be in this head. :e-shrug: Two were split, other 6 were still in place. Only been a couple years, but they were still flexible. Put the cam back in and found they're all a little tighter than I'd like, but nothing too terribly bad. May reshim, may not..head is coming off soon anyway for RSI springs & cam.

target:
015 intake
017 exhaust

016e .145 = .144
013i .145 = .143
015e .153 = .151
012i .156 = .153
015e .153 = .151
009i .153 = .147
014e .154 = .151
009i .153 = .147
 
Well if the distributor is off a tooth it just means the rotor will be off - timing is still be accurate care of your trigger angle.

If you move the dizzy, you'll have to reset your trigger angle, but if it was off enough the spark couldn've been jumping further than it needed to. /benchrace - I'm not sure if the spark having to jump would result in misfires or a weaker spark /end benchrace.

Win on the rubber isolators being the 'issue'.
 
I'm not moving the dizzy now, I'll wait til I get it put back together and I'll verify timing again.

I think I'll try to "fix" it. I'm looking for anything right now that might not be right in hopes of fixing the slow spool.

Also going to pull the WG rod, trim it if needed, shorten some more, and really preload it a lot. It should spool faster and spike if I preload it enough...
 
The shimventory has what I need...reshim cam tomorrow, hopefully test drive by mid week and see if I can find any more issues.
 
shimmed the cam, no more 0.009" clearances on intake valves.

remembered that the dizzy was off before so I just move the intermediate gear on the timing belt to align the rotor with #1 at tdc rather than move the dist. so I popped the dizzy out and moved it over so it's pointed at 1 with the int. shaft timed right according to the belt. that'll make things easier in the future I assume.

tonight I'll shorten the WG rod some more, jump start it, set ign timing (since I moved the dizzy) and hopefully test drive it.
 
Success?

rafresh-refresh-F5-eccbc87e4b5ce2fe28308fd9f2a7baf3-185.gif
 
went to play volleyball after work, ended up drinking some coors lights, just got home...no update. put your F5 away. maybe friday night, plans tomorrow night.
 
MrBill said:
I can't imagine if your car was as fast as robs car was when it blew up :omg: That'd be so god damn awesome.

hurry up!
Click to expand...

I know!!! that's all i want. 18-20psi of instant-on boost. pretty much what I'm setting out to replicate now with this dumb header. no idea why it's not working with the 90+, something somewhere is wrong and I don't know what. so lets throw parts at it
 
Yes? I think I'll go see ben about chopping off the flange. I need to order a spool of wire to mig the flange back on. That should give me enough practice to be able to weld on a WG pipe. I might need different wire to weld the mild flange to the stainless pipe that I also need to buy. Or a stainless flange? Haven't got that far yet. Also have to hole-saw the collector for the WG pipe. I'll get to it eventually...
 
towerymt said:
mbc
Click to expand...

You're not going to get instant on boost with a mbc :-P

the MS has boost control capabilities, you just need to get a boost control solonoid.
http://www.diyautotune.com/catalog/ebc-electronic-boost-control-solenoid-kit-p-285.html

It'll actually hold your waste gate closed until you're close to your target which makes you build boost a lot faster than a mbc...

if you get a 4 port solenoid it's supposed to be even faster:
http://nissanroadracing.com/showpost.php?p=67854&postcount=14
 
Last edited:
eage8 said:
You're not going to get instant on boost with a mbc :-P
Click to expand...
I should. I don't get instant boost with the line to the actuator disconnected, either. :lol:

I'll probably look at EBC once I figure out the fundamental problem that keeps my little GT2871 from spooling til after 3000rpm.

The exact same turbo on a nearly identical 2.3 volvo engine made boost much much sooner, but it had a tubular manifold and external gate w/ball&spring mbc. So I know what it should do and how it should feel...I got to drive it. I should be able to make boost so fast that I'd have traction issues in 2nd gear even on the Hoosiers. THEN I'd look at EBC or a bleed valve to slow down the boost buildup. I wish that were my problem...
 
It started up with a jump start. Rotated distributor to set timing at 15 while I had it set to 15 fixed in MS.

Shortened wastegate actuator rod again. Now requires vise grip pliers and a pry bar to reinstall. Didn't do anything for spool between 2000-3000. Just makes 20psi with the mbc unthreaded til it's about to fall apart. I'll try a run this week with no hose hooked up and see if it spools with WG held shut. Not likely

Bumped timing from ~1700-3100, 60-140kpa. Added in 3-8 degrees and finally got a little ping sometimes at 2500, but it's still not spooling. MAYBE slightly quicker from 2700-3000, but still only about 7psi I think at 3k. The fun doesn't begin til 3k, then it's all in somewhere around 3500 (if I paid attention to that).

I think I'll pull 15 degrees all over and then see if it goes really sluggish, then start adding it back in.

Need a timing map for a tight squish ~9:1 8v......
 
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