248 wont turn again

April 28, 2013

Once again my motor wont turn over without a crowbar but this tme its in the car. the crank was machined down, got new poured bearing connecting rods, new main bearings,piston rings. everything is torqued to scpec per the book. i confermed everything with a freind thats been helping me and he agrees that everything is right were it should be. the starter wont turn it, you can here it engage the fly wheel. we hooked a tow rope up to it and dragged it down the strret and still wont turn over. what am i missing. do i have things to tight? any one else have this problem? this car has been fight tooth and nail through this entire process. HELP!!!!

April 28, 2013

At least the paint paint looks nice.

TexasJohn55 · April 28, 2013

Did it turn freely before you put in back in? Did you bolt it up to a dynaflow? TexasJohn55

Bill Stoneberg · April 29, 2013

One thing was suggested elsewhere which was to pull the plugs and see if it will turn over

JohnD1956 · April 29, 2013

Once again my motor wont turn over without a crowbar but this tme its in the car. the crank was machined down, got new poured bearing connecting rods, new main bearings,piston rings. everything is torqued to scpec per the book. i confermed everything with a freind thats been helping me and he agrees that everything is right were it should be. the starter wont turn it, you can here it engage the fly wheel. we hooked a tow rope up to it and dragged it down the strret and still wont turn over. what am i missing. do i have things to tight? any one else have this problem? this car has been fight tooth and nail through this entire process. HELP!!!!

Are you sure it's not an issue with the starter itself?

critterpainter · April 30, 2013

You say everything is torqued correctly, but were the bearing clearances checked? The rods might be an issue if they were not checked during assy.

Bill

May 1, 2013

all clearences are good, it did not turn freely before i put it in without a crowbar on the fly wheel, so i backed off the torque on the connecting rods and still didnt help as you can read.. so im going to do it again this time while its in the car. which will be a pain but i gotta get the car going.

May 1, 2013

This might be totally off the wall but I was trying to think of all the different engine components that interact with the rotating bits and the only thing I can think of that has not been mentioned is the fuel pump. Say the arm on the fuel pump was locked up and/or in a bind with the cam. Would this be enough to keep the engine from turning? Just an outside of the box type suggestion for you. Good luck!

avgwarhawk · May 1, 2013

One thing was suggested elsewhere which was to pull the plugs and see if it will turn over

I concur. Take the compression out of the picture. Let the starter attempt to turn the motor when the plugs are out.

TexasJohn55 · May 1, 2013

Countrywill, You are obviously bound up on a rotating component, crankshaft most likely. Did you overhaul this engine or only replace bearings? Was the engine tight or runnable when you removed it for repairs? To check if it is a rod or main, each rod should shake sideways freely if you have running clearance.If not, loosen that rod to see if it frees up. If tight on main bearing, pry between crank throw and cap with a heavy screwdriver, first forward then back to check crank end play. If it slides freely back and forth then you have running clearance on the mains. If not, loosen main caps and finger tighten bolts and recheck one at a time until you find the tight one. No end play or no movement would isolate it to the crank and components on each end. If no problem is found on either rods or mains then it is a driven component, ie: camshaft, distributor or a belt driven component. Have you loosened belts? That pretty much covers it unless your cylinders have rusted over. Give us some history so we don't have to do so much guessing, makes diagnosing much simpler. TexasJohn55

May 2, 2013

thanks for the replies. my thought is the torque on all the rods. i went off of advice that i got from here and not by what it said in the book which gives no torque description except tighten until a slight drag is felt. so thats what im going to do.

Bill Stoneberg · May 2, 2013

While I am thinking of it and because I have done it too, How did you time your cam ?

If you lined up the 2 marks on the timing gears it will not start.

On the old timing chains there used to be two copper links that you line up with the marks but now with the repro chains you have to count.

It talks about this in the shop manual.

TexasJohn55 · May 2, 2013

QUOTE: "thanks for the replies. my thought is the torque on all the rods. i went off of advice that i got from here and not by what it said in the book which gives no torque description except tighten until a slight drag is felt. so thats what im going to do. " THAT SAYS IT ALL. GOOD LUCK, YOU WILL NEED IT. I'M OUTA HERE.

May 3, 2013

@ Bill. I counted links on the chain to make sure it was the corect size, due to the place i got it from wasnt realy sure what buick it went to. I counted the links between the copper links and matched them up to the "silver links" on the new one, and everything matched nicely till i realized i forgot to put the backing plate on first..oops. I dont think that would afect it to not turn over even by dragging it down the street.

Bill Stoneberg · May 3, 2013

Wont make a difference, just something I thought of after talking to you the other day. I have had numerous calls about that.

critterpainter · May 3, 2013

When assembling the engine, did the piston assemblys go in with just a slight nudge from a hammer handle or did you have to force them down? Did the crankshaft rotate before the rods were installed? Are the piston rings cast iron or chrome moly? If CI did you lube them before assy?

Loosening the rod bolts is NOT kosher. The rods need to be torqued to 40-45# and you should have about 1 1/2 thousands clearance on the bearings if I recall correctly. Did you use an assembly lube or assemble everything dry?

Bill

May 5, 2013

Critter, pistons with nos rings went in with a tiny bit o pressure, The crank did spin nicly before rods were installed, I did use assembely lube during the build process, Well hopefully il be able to pull the pan off next weekend and see whats going on in it. im starting to think this car just doesnt want to run any more. Ive been fighting every part of it. I get so frustrated then this morning a little kid on his bike rides up and starts talking to me about it and how cool it is while he looks through the window. he was disapointed that it didnt run, hes seen it in my garage over the past year. the look he had is the same look i had when i was his age, so now i have to get it going. arg the pressure......

jsmittie41 · May 7, 2013

Back in the 70's I rebuilt a 248 for a 41 special. I took out the babbited connecting rods and put in insert bearing rods from a later model engine and this worked out fine. i also put in new standard size crank bearings and experienced the same problem you have. I used plastigage to check the clearances and when properly torqued down I couldn't turn the crank. Long story short. I purchased super thin copper shim material and shimmed the main bearing caps to loosen them up. It worked for me. the car ran great. I sold it a few years later to a fellow who used it as a commuter car. I have a 41 block here and there are copper shims between the caps and block. Smittie

May 19, 2013

I loosened all the c-rods and re torqued them to 20 pounds, i still cant turn it but the motor did spin alittle when i drug it behind my freinds truck. i could here it poping as it spun. it was enough to pump gas to the carb, so its alittle progress. im not sure if i got the plug wires correct, i was going off of old pics of the engine but it wasnt very clear. im at aloss right now, so i have to sell it the way it is. thanks again for all the help

buick man · May 23, 2013

By forcing the crank to turn over by dragging it behind by a rope most like did severe damage to the bearings and the crank journals. I think you are back to pre rebuild and square one. If the crank would not turn even with the spark plugs out of the head why would you force it to turn by dragging it behind a car ????

May 23, 2013

It was rocommended to drag it by acouple of people who have encountered this them selves

Caballero2 · May 23, 2013

I do not know about your vintage of Buick, but a similar problem was persistent with my '57. I uncoupled the engine from the transmission and loosened the bell housing bolts. The engine then easily turned over. I pulled the engine and removed the torque converter after determining that the converter was dragging something. It turns out, the bell housing to transmission case, one bolt was not torqued down with 1/4 inch remaining under the head of the bolt. I then created another problem which required a rebuild of the transmission. I allowed one of the input shaft seal rings to break and get ground up in the front pump. Do not let the solution to the immediate problem become a serious secondary problem. All is well with the '57 now. Dan

buick man · May 24, 2013

It was rocommended to drag it by acouple of people who have encountered this them selves[/quote
This reminds me of a story I heard about and it goes something like this .... One snowy and very cold day a couple of years or so after dynaflows came out, a Buick owner just could not get his Buick started. So as a last resort, he goes over to his neighbor and asks him if he could give him a push start since neither had jumper cables and it was just too cold anyways. So they ready things and when it comes time and before they got into each car, the Buick guy tells his neighbor, remember this new type of transmission is different from a clutch, you got be going at least 20 mph before you can even think about getting this thing started. So his neighbor waves, gets into his car and then as suddenly drives around him and disappears around the corner. What the .... the Buck guy thinks to himself. Then after a few minutes there is a sudden and violent jamb from behind that pushes his car down the icy road. After the shock, he gets out of his car to find a mashed rear end. "What the *#@% did you do that for?" he asks his neighbor. "Well" said the neighbor "You said I had to be going at least 20 mph before you could get your Buick started!"

old-tank · May 24, 2013

Once again my motor wont turn over without a crowbar but this tme its in the car. the crank was machined down, got new poured bearing connecting rods, new main bearings,piston rings. everything is torqued to scpec per the book. i confermed everything with a freind thats been helping me and he agrees that everything is right were it should be. the starter wont turn it, you can here it engage the fly wheel. we hooked a tow rope up to it and dragged it down the strret and still wont turn over. what am i missing. do i have things to tight? any one else have this problem? this car has been fight tooth and nail through this entire process. HELP!!!!

New poured bearing connecting rods? Did you set the clearance using shims and check with Plastigauge? Same with the mains (was the crank spinning freely before adding connecting rods) I don't understand this variable torque on the rod caps...most are torqued to something like 45 psi...at 20 psi I would expect the cap to come off in a few miles.

Were the piston and ring clearances checked? Too little ring end gap and a slightly tapered bore will bind big time.

"Some disassembly required"

Willie

June 2, 2013

Yep everything was plastigauged and clearences were double checked. i made a freind check also. I did get it to turn but i think i might have fried the clutch in the process im not sure. Does any one have a diagram of the firing order or can tell me were the hell is the #1 cylinder on the distributer. i might have gotten it mixed up. Ive fell in love with a straight 8 but i hate the straight 8. this is driving me crazy

Bill Stoneberg · June 2, 2013

Turn the engine till you can see the TDC mark on the flywheel, Its in a little window on the back side of the passenger compartment. This will show you where Number 1 cylinder should be. Firing order 1s 1 6 2 5 8 3 7 4 Distributor turns COUNTER Clockwise.

pont35cpe · June 2, 2013

If the crank and cam are out of time, piston could be hitting a valve stopping the rotation...Can you turn the engine backwards? Tom

smithbrother · June 2, 2013

I'm no expert on straight eight's, but follow #1 cylinder plug wire back to the dist. I would guess the cap can go on ONLY ONE WAY,.

I wish you well,

Dale in Indy

buick5563 · June 3, 2013

Does any one have a diagram of the firing order or can tell me were the hell is the #1 cylinder on the distributer.

Will,

I assure you that I am not trying to be a jerk.

What does your Shop Manual say. I have ZERO knowledge about your 248, but all of this information should be in your Shop Manual. The Shop Manual would have the firing order, the distributor wiring etc.

What does it say???

Aaron65 · June 3, 2013

If the crank and cam are out of time, piston could be hitting a valve stopping the rotation...Can you turn the engine backwards? Tom

Straight 8 timing gears do not line up dot to dot like a V8's would...The shop manual shows how they should be lined up, so could this be a possibility?

Caballero2 · June 3, 2013

countrywill: My earlier suggestion would only apply to a Dynaflow equipped car. However a rather simple check can be done to verify the cam being out of time with the crankshaft. That is, remove the rocker arm assembly and push rods. Check that the ends of the valve stems are in the same plane. They should be. If not you probably have a bent valve. If the stems are in the same plane, the engine should turn easily with the spark plugs out. - Dan P.S. there will be minor variations in stem length due to seat and valve head grind operations

Edited June 3, 2013 by Caballero2
Added P.S. (see edit history)

JohnD1956 · June 3, 2013

I thought these were non interference engines, in that the piston cannot hit a valve?

At any rate, I would follow Robert Trails advice from above. Start removing the things that rotate with the assembly and see if one of them is bound. Remove the fuel pump, then the distributor and if you still have the pan off, then the oil pump. If none of that produces a loose engine than you have to remove the rocker arm and if nothing then by process of elimination you are back to interference somewhere between the pistons and rings like Willie suggested.

By the way, before doing any of this, I assume you did have someone push the clutch in to eliminate the trans as a source of the problem.

60FlatTop · June 3, 2013

With the valve cover off, you can turn the engine in the correct direction of rotation and watch the valves on #1. First watch the exhaust valve, watch it close, rotate until the intake opens, then turn and both intake and exhaust will be closed. Now you are on the compression stroke. Turn it a little and watch the damper marks or through the flywheel window, depending on what you have. Then slip the distributor in with #1 terminal where you want it and the rotor slightly before the terminal.

You're pretty close and it should start.

Bernie

buick5563 · June 3, 2013

With the valve cover off, you can turn the engine in the correct direction of rotation and watch the valves on #1. First watch the exhaust valve, watch it close, rotate until the intake opens, then turn and both intake and exhaust will be closed. Now you are on the compression stroke. Turn it a little and watch the damper marks or through the flywheel window, depending on what you have. Then slip the distributor in with #1 terminal where you want it and the rotor slightly before the terminal.
You're pretty close and it should start.
Bernie

NOT if the wires aren't in the proper order on the engine or cap. (Ask Bill or Willie how I know (whoops)).

NOT if the crankshaft won't spin.

NOT if the timing chain isn't correct and the cam and crank are out of sync.

There are too many unknowns.

None of these things have been confirmed with somebody with a Shop Manual in front of them.

I have rebuilt several engines and each time I had the book out. I still effed it up when wiring and I had my guru standing over me calling me a bonehead.

I am lost as to what has actually been confirmed as correct after 33 posts on the second thread pertaining to this issue.

Sorry

buick5563 · June 3, 2013

I'm seriously NOT trying to be a Pooh-Butt here. We have ALL made mistakes, and we ALL have to ask for help once in a while.

Take it step by step...

Roadmaster75 · June 4, 2013

You need to remove that engine and get it back on a stand.

You said the crank turned after assembly into the block....... right?

In my opinion you now have potential compounding problems that need to be systemically eliminated

OUT of the CAR!

Then review ALL the good suggestions presented on this thread; especially,

valve train related & torque converter interference related potentialities OUT of the CAR!

If you don't have a shop manual and a basic set of micrometers and vernier calipers available to you;

get them NOW.

You need to definitively determine if you have the correct timing chain & then proceed to

ensuring it has been installed correctly.

You will need to assess any damage potentials from dragging the car with a hard interference problem.

NOTE:

Caballero's suggestion of interference at the flywheel/torque converter should be checked and double checked;

preferably, with the trans out of the car and bolted to the engine out of the car ....

Put a known good starter on the assembly once all this checks out and make sure it turns over BEFORE you re-install everything back

in the car..... You WILL get it solved & you WILL get it running ...listen well and provide clear,specific feedback to this group

point by point & I predict you'll be driving

this car all summer ...!

mike

TexasJohn55 · June 4, 2013

Once again my motor wont turn over without a crowbar but this tme its in the car. the crank was machined down, got new poured bearing connecting rods, new main bearings,piston rings. everything is torqued to scpec per the book. i confermed everything with a freind thats been helping me and he agrees that everything is right were it should be. the starter wont turn it, you can here it engage the fly wheel. we hooked a tow rope up to it and dragged it down the strret and still wont turn over. what am i missing. do i have things to tight? any one else have this problem? this car has been fight tooth and nail through this entire process. HELP!!!!

all clearences are good, it did not turn freely before i put it in without a crowbar on the fly wheel, so i backed off the torque on the connecting rods and still didnt help as you can read.. so im going to do it again this time while its in the car. which will be a pain but i gotta get the car going.

thanks for the replies. my thought is the torque on all the rods. i went off of advice that i got from here and not by what it said in the book which gives no torque description except tighten until a slight drag is felt. so thats what im going to do.

Critter, pistons with nos rings went in with a tiny bit o pressure, The crank did spin nicly before rods were installed, I did use assembely lube during the build process, Well hopefully il be able to pull the pan off next weekend and see whats going on in it. im starting to think this car just doesnt want to run any more. Ive been fighting every part of it. I get so frustrated then this morning a little kid on his bike rides up and starts talking to me about it and how cool it is while he looks through the window. he was disapointed that it didnt run, hes seen it in my garage over the past year. the look he had is the same look i had when i was his age, so now i have to get it going. arg the pressure......

I loosened all the c-rods and re torqued them to 20 pounds, i still cant turn it but the motor did spin alittle when i drug it behind my freinds truck. i could here it poping as it spun. it was enough to pump gas to the carb, so its alittle progress. im not sure if i got the plug wires correct, i was going off of old pics of the engine but it wasnt very clear. im at aloss right now, so i have to sell it the way it is. thanks again for all the help

Yep everything was plastigauged and clearences were double checked. i made a freind check also. I did get it to turn but i think i might have fried the clutch in the process im not sure. Does any one have a diagram of the firing order or can tell me were the hell is the #1 cylinder on the distributer. i might have gotten it mixed up. Ive fell in love with a straight 8 but i hate the straight 8. this is driving me crazy

..........

buick5563 · June 4, 2013

Let me help TJ55 here with some comments (IN BOLD)