Help with 3.2SS Rebuild - Hard Crank

alphie · 05:45 PM

Looking for tips, please... Engine hard to crank!

This is my first build. The engine is 3.0 case, 98 mm max mortiz pistons, dc20 cams, supertec racing springs, dual plug. deck height is 1mm, intake valve to piston clearance is 1.5mm.

When I first installed the engine I found the engine wouldn't turn over at all. The fan pulley would just slip. Its hard to get a wrench on the crank pulley nut, my 17mm wrench couldn't turn it either. Figuring I messed something up, I pulled the engine right away.

I found a couple things, the engine WOULD turn over, albeit not easily, with a proper socket on the pulley. I rechecked the valve adjustements and all seemed fine. I put the engine back in, pulled the plugs, boosted the battery and the engine would spin and build oil pressure.

With the plugs in, the engine cranks VERY slowly. Had the starter tested and even bought a new high torque starter plus a new battery. Checked a lot of electrical connections as per the pelican tech article and all seem okay. I even attached another battery to the starter directly, same result.

I think something isn't right with the engine. Without plugs, and turning by hand, the fan pulley nut will spin the engine easily for about 1/3 of a revolution on the pulley then it gets VERY hard to turn. I figure things to check are timing and valve adjustments. My question is what should I check first BEFORE I pull the engine from the car.

Help is greatly appreciated. I'm getting quite depressed as I started this project in April!

356RS · 356RS's Garage

So during your rebuild there was never a problem turning the engine over? But as soon as you installed the engine, It's hard to turn over, right?

alphie · 10-18-2006, 04:14 PM

That's an excellent question and I wish I could say for sure one way or the other.

Prior to putting the engine in the car I could turn the engine over with my 1/2" socket drive on the 17mm pulley nut. The fan pulley nut could only turn it over a certain amount before the belt would begin to slip. With the engine in the car I can't get my socket on the pulley nut but I can get a 17mm wrench - that becomes very hard to turn over and I have to use that with the fan pulley nut at the same time.

It could be binding but I'm not sure. The problem is I don't have much experience in that I don't have a good feel for how easily the engine should crank over, by hand.

sww914 · 10-18-2006, 05:17 PM

When you were adjusting the valves was it easy to turn around?

alphie · 10-18-2006, 06:50 PM

Easy to turn? That's what I'm not sure of as I don't have a basis for comparison. I remember that it turns easy for part of the revolution then as the cam lifts the valves it gets harder. Resulting in a easy-hard-easy-hard, etc, revolution. Is it normal for dc20 cams with racing springs to behave that way, I can't say.

sww914 · 10-18-2006, 09:07 PM

That sounds completely normal. Are you able to get a socket on the crank instead of the fan pulley to try to turn it? The fan pulleys usually slip when turning an engine over, I would expect a fresh engine to be even more difficult to rotate.
I'm encouraged to hear that you could turn it over while adjusting the valves without too great an effort, that means that the problem is further out (away from the deepest bowels of the engine) than that, I suspect there may be some interference in the bellhousing of maybe the pilot bearing is really jacked up for some reason.

alphie · 10-19-2006, 05:08 AM

The last time I adjusted the valves, the tranny was attached. I think the resistance is the same with the tranny or not.

The new hightorque starter turns the engine over a bit better than the old starter. I was expecting it to fly. Again, without the plugs in, it turns over much easier, with the plugs I'd say its turning over about 100 rpm.

eapcpa · 10-19-2006, 05:57 AM

Are you sure the battery is good, all connections are clean and most importantly you have properly grounded your engine to the chassis and the battery to the chassis. If you have a bad or dirty ground, no matter how much energy you put into the starting system you will be limited by the bad ground. The braided ground cables develop high resistance over time. Replace them. If it turns over without plugs in it that likely has eliminated internal friction at the bearings. Also you might check your timing but it sounds like it does not turn over enough to make that a factor. Have you pulled the fuel pump relay so it does not flood?

cstreit · cstreit's Garage

Did you turn it over by hand after you installed all the rockers?

Is the clutch cable adjusted and installed properly?

alphie · 10-19-2006, 06:24 AM

Yes, I turned it over by hand after the rockers, which is how I adjusted the valves.

Since I'm a newbie, I believe the clutch cable is adjusted properly as I followed the method in Wayne's 100 projects book. If it isn't adjusted properly, what effect would that have on the engine cranking? With the tranny in neutral and depressing the clutch pedal...?

alphie · 10-19-2006, 06:28 AM

I did pull the fuel relay, and the connection to the cdi box. I conducted a ground test at the tranny ground line, as per the tech article on pelican, and it seems good. I also connect a battery directly to that cable, however, now that you mention it, I didn't check the ground connection at the tranny itself, but rather at the strap that attaches to the chassis.

I also conducted a under load ground test at the fan shroud and that seemed great as well.

The battery is new and boosted by my other car battery (car running).

I'll check the strap itself.

356RS · 356RS's Garage

With the information you have given, and being your first build, I see "IMHO" two options. First, find someone close by that has some experience in these engines and see what he thinks about the hard-to-crank issue. He might say it's just new and tight, lets get it running ( i hope not). Second, take it back out and fine whats causing the drag. This is what I would do. You have put lots of money in this build, hate to see it freeze-up. I hope someone on the list can put there finger on the problem with the information you have given.
Keep us posted.

alphie · 10-19-2006, 11:00 AM

Thanks Mark.

I bypassed the negative strap using a booster cable between the chassis and the tranny. Same results. Slow cranking turnover.

Question for people with higher compression engines. With the plugs out and the fan belt adjusted properly, are you able to fully turn the engine by the fan pulley nut? With the plugs out, might won't turn when the cams start to lift the valves.

Can anyone recommend what I can check mechanically before I pull the engine, yet again?

Another question, can I make an access hole in the engine mounting to allow me to get a socket on the pulley nut? The pics in Wayne's rebuild book have such a hole but mine does nut.

PJMARKOW · 10-19-2006, 01:23 PM

Could it be that you are getting coil binding in the valve springs? You say you put new springs in, and it's a high lift cam. Just something else to check.

Cheers

alphie · 10-19-2006, 05:11 PM

Hi, could you explain what coil binding is?

thanks

89turbocabmike · 10-19-2006, 06:31 PM

Alphie, you may already be doing this, but if you push the fan belt in the center between the two pulleys(on the right side) as you manually try to turn the engine over, it will help the belt get a better bite on the crank pulley.
I wish I could help with gauging the degree of effort required to turn the motor over. Perhaps if you have a torque wrench you could quantify the effort and someone with a similar compression motor could do likewise. My low-compression turbo would not be a very good comparison.

89turbocabmike · 10-19-2006, 06:33 PM

Coil binding is when the coils of the spring hit each other under compression. IE, the spring is fully compressed.

len911 · 10-19-2006, 06:44 PM

Coil binding is when you spring get compressed so much that the separation betweeen the coils dissapears, acting as a solid piece of metal. A high lift cam with standard springs could cause coil binding. You could check for it by removing the valve cover and observing the spring. Lou

alphie · 10-20-2006, 04:24 AM

I'll give that a try. The cams aren't that radical but its worth checking.

Does this sound reasonable? If I back off the rockers and try to turn by hand and it DOESN'T get easier to turn then I can assume it is not valves, yes?

MBEngineering · 10-20-2006, 11:00 AM

HI at just what spring hight did you set the valve springs to , that is with the shims under the valve spring retainer in the head????? you should have the setting info with the cams or springs.

regards mike