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Discussion Starter #1
Little stumped and figure I might as well just ask.

Got a DART SHP 400, it is internally balanced and 2 piece main.

I "thought" I ordered the correct flexplate and here is what I got.
https://photos.app.goo.gl/ZggQV46GtvnH9FZ16
There is a gap from the converter to the flexplate (this is a crappy photo but is a consistent gap) and it can't be closed as the converter snout is buried and I think the converter is buried agaist the FL bolts.

The FP is a SCAT FP-350-SFI and I thought an internally balanced SBC with a 2 piece rear took a 350 flexplate...

Where did I go wrong? Even flipped the FP around to make sure I wasn't crazy and it was super close with almost 0 gap between the flexplate and the converter.

Little help would be great.
 

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Your flexplate is correct. Whatever is causing the torque converter not to mate to the flexplate properly is in the torque converter. Maybe the nose is too long? That sort of thing.

You may have a converter that's made for use with a 1/4" motor plate like you'd see in a drag race car.

Without doing a complete assembly, try putting another converter against the flexplate/crankshaft and see if it will mate up close.
 

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Do you still have the old one? Find a flat surface and measure the both of them, if there is a difference, you should find it.
 

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Mike - 74 Nova Baltimore, MD
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This converter was in the car before. I freshened the motor and my FP expired so I bought a replacement.
I'm thinking this car is raced due to the fact that you replaced an SFI flexplate due to expiration.

My guess is the the convertor may have ballooned. Do you know if this converter has anti-ballooning plates?

Take a look at the flexplate you just replaced. Does it appear to be bowed-out around the circumference?
 

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I think Scat flexplate is made by Pioneer. I could be wrong, but I think it is. Anyways I have a new Pioneer(SFI approved)flexplate for my 400 build. I've ordered Summit brand one time before and it was made by Pioneer. Anyways if you need a picture or measurement I can get one. If you look closely on it you might see a Pioneer # on it or their name.
 

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I never changed the flexplate in my car. If it wasn’t damaged it was fine.
 

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Discussion Starter #10
The old flexplate is no where to be found, not sure what the hell I did with it but it isn't showing up.

I verified the problem is the converter is hitting the flexplate bolts before it can meet the raised mount tabs on the flexplate. I also verified the snout will fully seat in the crank if there is no obstructions with the flex plate bolts. I'm using my ARP flexplate bolts which were in the car before as well. I also threw the starter on and found the starter drive is engaged with the flexplate ring gear while at rest.

Here is a pic of the flexplate and converter bolts.
https://photos.app.goo.gl/nvyAA2oVd2w13Gyy7

Seems to me the center section of the flexplate should NOT be raised as that would put the flexplate closer to the converter so that the converter can mate to the mounting tabs and provide the spacing to pull the starter gear off the flexplate ring at rest.


Starting to wonder if I actually have a 1 piece rear main seal? How does that effect the flexplate?
 

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Discussion Starter #12
I don't think SHP blocks are 1 pc.
I can see your issue now.
I think mine is flat but ill go out in the garage and look.
I guess I thought DART SHP's were 2 piece also but here is a 1 piece.
https://www.summitracing.com/parts/drt-31161211l/overview/

Really starting to feel like a dope. Just went thru all my stuff and found my original order (short block) but there is no mention of 1 versus 2 piece rear main... I just took it for granted that it was a 2 piece.
 

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IF the following new 1 piece FP does not fit, I guess I'll be popping off the pan.

https://www.summitracing.com/parts/tci-399774
You run a Kevko pan don’t ya? Look and see what pan you ordered. A pan for a 1 piece or 2 piece seal. I’m betting you have the 2 piece rear main. I run the 153 tooth flexplate in my 421 that was on my 355. Think I threw the SFI 168 tooth flex plate away that came with my shp block.
 

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Mike - 74 Nova Baltimore, MD
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You should be able to tell if the block is a 1 piece rear main or a 2 piece rear main by removing the flywheel and looking at the back of the block where the crank shaft comes out. You should not have to remove the oil pan.

Do you see a bolt on flange/cover that looks like the one shown in post #14?
If so... you have a 1 piece rear main seal.

If you do not see anything that looks like the image in post #14.... you have a 2 piece rear main seal.

Check out the video below. It is a Youtube post the shows the differences between a 1 piece and a 2 piece rear main seal in a small block Chevy. Just go to 1:45 into the video to begin watching. At 4:20 into the video, you will also see the differences in the crankshafts used for each type of seal.

 

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The flywheel bolt pattern for 1 piece main seal is different from 2 piece, so if you had the wrong one it won't bolt up.
 

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Discussion Starter #19
You run a Kevko pan don’t ya? Look and see what pan you ordered. A pan for a 1 piece or 2 piece seal. I’m betting you have the 2 piece rear main. I run the 153 tooth flexplate in my 421 that was on my 355. Think I threw the SFI 168 tooth flex plate away that came with my shp block.
Yep, 2 piece pan was ordered... WTF, is going on here? Did I get a bogus FP? What else might I be doing that is wrong.

Converter is seated all the way
FP mounted raised tabs toward converter
Used proper FP bolts
Mated tranny/block fully

Really not more to it right?
 
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