FLEXPLATE QUESTION

[BPTTONE420012]

so i re-used the flexplate and starter off of my 1986 305sbc on my 350sbc vortec motor that was out of a 98 suburban.... only thing that was kept off of the 350 sbc was the block... everything else is NEW... my question is, will the flexplate off of the 1986 305 work properly on my new 350??? i mean it fit perfectly, bolted up without a problem, but i was told it could cause vibrations by a friend... the BALANCED eagle rotating assembly is "ESP B13402L00053" and the harmonic balancer is an 8" internal balanced "NAL 10243271".... both motors are one piece rms... so i guessed that the flexplate would work and installed it.... was i wrong to assume this???

 

[ssn696]

The pre-1986 cranks were neutral balance, and the 87-up cranks use a weighted flexplate. When race shops balance a motor, they genreally ask you for your damper and flexplate and balance the whole assembly together. I 'assume' that the pre-balanced kit you bought was set up with or for the stock flexplate. YOu might call/email and ask, but I bet it will work just fine. I hope the starter holes in the block are the same...

 

[BPTTONE420012]

The pre-1986 cranks were neutral balance, and the 87-up cranks use a weighted flexplate. When race shops balance a motor, they genreally ask you for your damper and flexplate and balance the whole assembly together. I 'assume' that the pre-balanced kit you bought was set up with or for the stock flexplate. YOu might call/email and ask, but I bet it will work just fine. I hope the starter holes in the block are the same...

yes the starter lined up, and bolted in just fine, lines up with the flexplate well... the flexplate has what i am guessing is a weight on it, on the side that faces the motor... if it is the wrong "style" of flexplate, what is going to happen on start up of the new motor??? i understand it will cause a vibration, but is the vibration going to be bad enough to destroy anything? will it vibrate the crank enough to eat a bearing or seal??? i am new to trying to build my own motor... I AM SO SCARED OF IT GRENADING ON START UP, having every penny i had plus borrowing over a grand to build this motor has me really afraid... if something goes wrong, i dont have any money to fix it... ALSO, I HAVE BEEN LOOKING AT A NEW PERFORMER RPM INTAKE BUT IT HAS THE EGR HOLE... CAN I JUST BUY A PLUG AND PLUG UP THE EGR HOLE?

 

[ssn696]

Put you r mind at ease...make that phone call to confirm the balance issue. There is no such animal as a neutral one-piece crank flexplate, so I think you are fine.

The Edelbrock kits usually had an EGR block-off plate included. The same passages in the center of each head both feed the EGR and the heating crossover under the carb for better warmups in cold weather. Some intake gaskets completely block these passages. So if you are not worried about warmup on cold Connecticut mornings, delete that whole feature...makes the carb run cooler.

 

[motorheadmike]

ALSO, I HAVE BEEN LOOKING AT A NEW PERFORMER RPM INTAKE BUT IT HAS THE EGR HOLE... CAN I JUST BUY A PLUG AND PLUG UP THE EGR HOLE?

The Vortec/E-Tec heads do not have an EGR passage, and the Performer RPM intake does not have a provision for EGR - so there is no work for you to do[/u] other than bolt it on. I've attempted to impart advice (and offered to sell you what you need) but it is falling on deaf ears as you continue to waste both my time and others.

Good luck sorting this out.

 

[BPTTONE420012]

ALSO, I HAVE BEEN LOOKING AT A NEW PERFORMER RPM INTAKE BUT IT HAS THE EGR HOLE... CAN I JUST BUY A PLUG AND PLUG UP THE EGR HOLE?

The Vortec/E-Tec heads do not have an EGR passage, and the Performer RPM intake does not have a provision for EGR - so there is no work for you to do[/u] other than bolt it on. I've attempted to impart advice (and offered to sell you what you need) but it is falling on deaf ears as you continue to waste both my time and others.

Good luck sorting this out.

yeah but you were out of town so i figured i might as well keep looking... still havent purchased an intake as of yet so if you still have it on tuesday, and are going to be in town and can mail it out asap then i will buy the one from you...

 

[motorheadmike]

The Vortec/E-Tec heads do not have an EGR passage, and the Performer RPM intake does not have a provision for EGR - so there is no work for you to do other than bolt it on. I've attempted to impart advice (and offered to sell you what you need) but it is falling on deaf ears as you continue to waste both my time and others.

Good luck sorting this out.

yeah but you were out of town so i figured i might as well keep looking... still havent purchased an intake as of yet so if you still have it on tuesday, and are going to be in town and can mail it out asap then i will buy the one from you...

Respectfully speaking - when know you want something, and want it at the drop of a hat: pay retail. If you want to save a buck on used stuff, you are just going to have to be a touch more patient.

Cheap. Fast. Reliable. Pick two.

 

[pontiacgp]

It's not easy to find a used intake for vortec heads to use with a carburetor and new ones aren't cheap. Patience is a virtue and with this intake it will save you money... 🙂

 

[truracer20]

The part number you posted is a complete rotating assembly including a 153 tooth flexplate. But the stock type flexplate will be fine for daily driving street use since 305 and 350 cranks are the same. Since the cranks are the same they also required the same balance so piston size and weight don't matter.

I do have to say that my experiences with factory Chevrolet flexplates isn't good, they tend to crack over the years, I would go with a new one while its all apart.

 

[BPTTONE420012]

The part number you posted is a complete rotating assembly including a 153 tooth flexplate. But the stock type flexplate will be fine for daily driving street use since 305 and 350 cranks are the same. Since the cranks are the same they also required the same balance so piston size and weight don't matter.

I do have to say that my experiences with factory Chevrolet flexplates isn't good, they tend to crack over the years, I would go with a new one while its all apart.

thats the problem, its not all apart anymore, i had used the flexplate off the 305 cause i figured it would work and it is in good condition minus light surface rust...so i bolted it up, put the motor in, and bolted it back up to the trans... and i have depleted all my funds plus went a little over a grand in debt... and the flexplate that came with the rotating assembly is MIA... thank you for answering, put my nerves at ease...