I have just rebuilt my 7.3l i.d.i. diesel and I noticed that when I started assembling the connecting rods to the crankshaft that the engine did not spin as freely after each one was installed... When I reached the point of installing the last piston and rod in the number 7 cylinder... I could hardly even get the engine to rotate at all... And mind you, this was with proper thrust set on the number 3 main bearing for the crank; and the main caps completely off! I decided not to torque the mains until afterwards, because of this problem.. This pistons slid right into the cylinders freely with a light tap, so I can't understand why the crank would spin freely with the mains torqued properly and no connecting rods installed at all... But not turn well with the heads off and the pistons and rods installed... HHHmmmmmm? PUzzElleD... Anyone know why this is happening... No starter will turn this monster over yet... Thanks for any input.... =)

 

Moved to the correct forum.

 

did you check your bearing clearences with plastigauge??? Sounds like you have one or more that arent correct.

 

also did you have it line bored?

 

Thanks for the tip!

 

I will start tearing it down again then... Any other tips on performance miss without going turbo... Please let me know. Thanks all =)

 

Since you have it all apart anyway, get ahold of russ and get a cam regrind.

 

Cool.. thanks a million... So will the regrind improve the torque or HP, or both when you turn it down?

 

Also... I read up on russ' cams, and I couldn't find find whether or not I would have to go with different rocker arms and push rods for the lift differences... Please advise your opinion of what you know... Thanks =)

 

Where do you read up on russes cams? And if you need push rods or rockers I'm sure he would say.

Chet

 

I found a discussion on them by a simple Google search...

 

Check your rods They have one side that is machined for bearing clearance on the crank throw edge and the other for rod to rod clearance. Each pair must be in correct or it will bind up the engine. I read that somewhere and put a note to self about it. If you get a typ4 cam you will be pleased with the extra performance.

 

Or you can get NMB2's camshaft....its more aggressive or something but it makes a great performance increase too.

 

I dont think NMB2s cam would be very friendly to a NA engine, hasnt let much out, but the shorter valve overlap wont help it any.

Russ' cam brings torque / HP in about 200 rpms sooner, i believe it was something like a 13% increase overall. Im sure he can give you more accurate and complete info. I think he is known by typ4 and is more commonly found at oilburners.

You wont need different valvetrain that i know of, MAYBE longer pushrods, but i think the lifters make up the difference. Comp 910 valve springs might be a worthy investment, but are probably only needed for higher boost or rpms.

 

Sounds good fellas..