Elacruze 505" engine build

[elacruze]

Taking a time out for the Power Tour...engine is all OK so far except the timing curve of the MP distributor is too quick, rattles some around 2500rpm while accelerating. Still tuning like mad, got the idle OK with and without the A/C, got the coolant temperature stabilized at idle, around 200*F, cold start is manageable, hot start is not too bad but at odds with the 15* base timing the engine wants to prevent temperature creep at idle. I have to look into the distributor and see if the vacuum advance is adjustable, or the weight springs-been way too long to remember.

Longest shakedown cruise in history starts tomorrow; Hagerty insurance has me covered for 125 miles of free towing...put your money where your mouth is, boy.

[elacruze]

OK, wow.

Power Tour is over, made it without any pit stops...

My Chrome ignition module coughed up it's internal ground between Valdosta and Montgomery, preventing any on-the-road tuning; we had to record events up until the software locked up and tune in the parking lot every morning. The faulty ground caused an erratic RPM signal which overloaded the software. Since it didn't quit altogether, I never took the time to replace the module with my spare, though looking back I should have...
I installed the spare orange box and it lasted about 3.5 minutes before dying a sudden and complete death. Oh well, it was 25 years old...

Since we were in the area I stopped in at Mancini's and picked up two orange boxes. Install immediately resulted in fast starts, smooth idle and steady tach needle. Driving became much more a pleasure, obviously the spark was scattering or dropping out more often than I could hear. Less knock too.

Anyway, the engine is exactly what I asked for-perfectly drivable, good vacuum at idle, and I expect that when we get the timing and fuel dialed perfectly it will idle comfortably at 850-900 RPM with the A/C on. I haven't seen higher coolant temp than 190* since the weather went below 95*, and don't expect heat trouble again.

The motor wasn't broken in when I bought it, and didn't loosen up noticeably until Indianapolis-about 800 miles from home. Good grief. I didn't even add ZDDP, just Royal Purple street synthetic 10w40. I changed the oil up here in Michigan to Royal Purple 20w50 motorcycle oil, since it still has the ZDDP in it. No sign of shinies in the oil or filter.

Adjusted the valves, which I could hear loosening up; I started with .008" on the intakes and .010" on the exhausts. Most were .011"-.015", with the #7 exhaust out at about .018". I put everything back at 8-10 and it's smooth and very quiet for a solid lifter motor.

I had some trouble with the throttle linkage due to time constraints, and it's only opening 2/3-3/4 of the way; even so, it's a torque monster of course...doesn't feel like it's going to make 600hp but it sure drives nice and will shred the tires in 2nd gear, even throwing a black cloud out the back since we haven't been able to dial the fuel at all above 1/2 throttle or about 3500 rpm.

More later.

[twodko]

Hey Eric,

All in all its sound like all your hard work and attention to detail has paid off in spades! Congrats man. 

[tufamc]

"Up here in Michigan"......As in ??

Im in Traverse City....

[elacruze]

"Up here in Michigan"......As in ??

Im in Traverse City....

We're down near DTW airport, but we will be getting as far north as Alma and Farwell...about 1/2 way up to you in Traverse.

[tufamc]

Gotcha......Enjoy the tour!!

[elacruze]

So finally got around to adjusting the valves...with one exception, they all loosened up .003"-.005". The motor is much quieter (again) and smoother, and more powerful to boot. I worked a bit on the throttle cable/bracket/lever and got it opening up 4/5ths or more...this thing can swallow some air! each TBI is 650 CFM, so full open is 1300 CFM...I figured I wouldn't see a lot of difference between 3/4 and WOT...boy was I wrong. I mashed it in second gear after the adjustments and everything that wasn't on the floor before went there fast!

I may make the Test and Tune at Milan Dragway this Friday or Saturday, for some MPH runs...won't be doing any hard holeshots this far from home, and the 255 Firestones wouldn't be much good for that anyway.

Pulled the plugs and the standard plugs are right about on the money for heat range, the shorty ND plug is too cold but not fouling. I'll order up one each of the other 3 ranges and swap them in until I find the right one.

[elacruze]

A short update on the #1 shorty spark plug-

I didn't take a photo yet, but did have the plug out while having maintenance pulled in Michigan. The plug looks great, no signs of damage from heat, detonation, or fouling. It's a good heat range from all I can see, although at $14 a pop I may not put them in the other 7 holes.

[greenpigs]

$14 for just one plug, dang!

So you didn't run it any to see the MPH I guess?

[elacruze]

$14 for just one plug, dang!

So you didn't run it any to see the MPH I guess?

MPH=80 max

MPG=14.6 max observed. With better timing and gearing I'm still confident we can find 25 under the right conditions.

[elacruze]

Back online.

Getting around to the stage II EFI again. Fuel rails/injectors test fit.

[oldschool]

A short update on the #1 shorty spark plug-

I didn't take a photo yet, but did have the plug out while having maintenance pulled in Michigan. The plug looks great, no signs of damage from heat, detonation, or fouling. It's a good heat range from all I can see, although at $14 a pop I may not put them in the other 7 holes.

be glad you dont have a plane. the plugs in mine are $95.00 ea. x 12........

[Rolling_Thunder]

Did you really fit bungs to an STR intake?       

[elacruze]

Did you really fit bungs to an STR intake?       

Yes, yes I did. I did I did I did, and I'm glad I found this a few years ago for $750 because the last one I saw asked $2500.

Now I have to build a custom plenum-I'll probably have to do something I'm not proud of with wood before having a custom top made. I'm pretty close to Wilson Manifolds, so if I find a spare $2-3k laying around I could have a first-rate beauty...

[XH29N0G]

Quick question related to something far back in the thred: 

Did you cut the flange on the header between 1 and 3?  If so, is there an advantage to doing this?

[mhinders]

Back online.

Getting around to the stage II EFI again. Fuel rails/injectors test fit.

Looking good!!! Here is my similar test fit of everything. Note the injector dummies and unwelded injector bungs.

[elacruze]

Quick question related to something far back in the thred: 

Did you cut the flange on the header between 1 and 3?  If so, is there an advantage to doing this?

No. These are Hooker Super Comp headers from about 1982. Back then, they had to have 2-piece pipes to get around the torsion bars. There is a slip-fit in tube 1 down below.

[elacruze]

Back online.

Getting around to the stage II EFI again. Fuel rails/injectors test fit.

Looking good!!! Here is my similar test fit of everything. Note the injector dummies and unwelded injector bungs.

Tell me about the coil pack, and how it's mounted...? Still something I haven't worked out.

I'd very much like to keep the distributor and plug wires but I haven't had an answer back yet from Electromotive about multiple signals to a single coil-it probably won't work due to saturation overlap.

[mhinders]

Back online.

Getting around to the stage II EFI again. Fuel rails/injectors test fit.

Looking good!!! Here is my similar test fit of everything. Note the injector dummies and unwelded injector bungs.

Tell me about the coil pack, and how it's mounted...? Still something I haven't worked out.

I'd very much like to keep the distributor and plug wires but I haven't had an answer back yet from Electromotive about multiple signals to a single coil-it probably won't work due to saturation overlap.

It's the GM LS2 truck coils, D-585, supposed to give the fattest sparks out there. I will mount them to the intake/heads with homemade brackets, still to be fabricated, nothing complicated needed.

The drawback with one single coil is that with 8 cylinders there is very little time to charge the coil when you start revving, and the sparks get weaker (unless you have a sophisticated ignition system transforming the 12V into 400V which is then passed thru the coil...). But a single coil is still ok, it tends to get a lot more complicated with one coil per cylinder... 

[elacruze]

Understood. The Electromotive box I have makes no allowance for single coils, so I expect saturation overlap; the charge time will be optimized for a single coil on 8 leads each rather than 1 coil lead with 8 impulses.

[mhinders]

Understood. The Electromotive box I have makes no allowance for single coils, so I expect saturation overlap; the charge time will be optimized for a single coil on 8 leads each rather than 1 coil lead with 8 impulses.

Sorry Elacruze, I didn't understand what system you had in mind, but now I've read about it!

If it can deliver 150mJ to the spark, that's very good indeed.

I seem to remember that my LS2 coils are delivering 134mJ (but this is a real measured value), and that in itself is also very good.
Yeah, that Electromotive box looks good, should take care of feeding the spark plugs with fresh energy at all revs!

[elacruze]

So, after a year or so of staring at this intake and wondering just what the plenum would look like if I made it myself out of plywood, or pottery, or fiberglass, or had the local welded-valve-cover yokel do it-so I did the smart thing and drove it down to http://www.wilsonmanifolds.com/.

They'll engineer it properly for volume, shape, flow, position and it will truly be jewelry! Of course, it will cost as much as a good watch but there's just no way I could cheap out on it without making it look like a piece of used drill casing.

Now I have to get onto the crank sensor. I'm taking the engine out soon to re-seal it; I'll have a look to see if I can have made a signal ring that fits onto the flywheel behind the ring gear, with the pickup in the bellhousing. More likely, it'll just go in the usual place around the crank pulley.

[mhinders]

I had the same idea...got my ring style tooth wheel from a company in England.
http://trigger-wheels.com/store/contents/en-uk/d5.html

[mauve66]

 

[elacruze]

Back from Wilson Manifolds. Strange, I'm thinking, that the computer-calculated plenum volume turned out to be exactly the same size as the stock Weiand plenum base x hood clearance. 

I spoke with Spectre at the Power Tour vendor trailer, an unnamed source there can help me out with the 2-into-1 TB to A/C adapter for cold air entry. The rails now bolt directly to the manifold with welded posts, so no worry about shaking apart and losing o-rings or injector seal.