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V8 rebuild Q’s


SteveG

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So today I just stripped down the 4.6 v8 to rebuild. A few questions....

After reading up, I assume I get a machine shop to check the block for any issues and re-line the crankshaft and camshaft? I assume they’ll need the crankshaft and camshaft to do this. I’ll also get them to fit new core plugs and oil gallery plugs. Is there anything else?

For the Camshaft, there are the high torque options, like the Kent 180 and the Viper stump puller. What are the implications on the tappets and push rods if you fit these? Also, do you need to fit pocketed pistons if you fit these camshafts?

Is the recommendation to fit ARP stud kits for the crank and heads?

Thanks, Steve 

 

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You only need to worry about tappets/pushrods etc. if you fit a really hairy cam, I have a Piper in the 109 and standard everything else.

Not sure what you mean by re-lining the cam&crank, you can grind (polish) the crank journals if they're worn, or just throw new big end bearings in. Cam bearings may have to be line-bored, not sure... I'd speak to V8 Developments about that you're doing.

This is my cam:

v8_camspec.jpg

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Thanks Jon

I read that if you replace the cam with a new different one, you should get the block line honed. But I’ve no idea what that is. 😉

i forgot to ask, what about the timing chain and gear set. Should you renew all of these too?

cheers, Steve 

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4 hours ago, SteveG said:

I read that if you replace the cam with a new different one, you should get the block line honed

If you get the cam bearings replaced they need to be machined to size after fitment, but the need for honing cam bearings when fitting a new cam is much less obvious. That's not one I've heard before. As Fridge says, V8 developments or Turner Engineering will be able to answer that one for sure.

Timing chain is a definite: they stretch and there's no tensioner to take up slack. New (genuine) tappets are an absolute must with a new cam too as the old ones will have worn with the old cam and would quickly wear a new one.

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21 hours ago, lo-fi said:

If you get the cam bearings replaced they need to be machined to size after fitment, but the need for honing cam bearings when fitting a new cam is much less obvious. That's not one I've heard before. As Fridge says, V8 developments or Turner Engineering will be able to answer that one for sure.

Timing chain is a definite: they stretch and there's no tensioner to take up slack. New (genuine) tappets are an absolute must with a new cam too as the old ones will have worn with the old cam and would quickly wear a new one.

 

10 hours ago, FridgeFreezer said:

Also the cam should come with assembly lube and instructions to run it in...

If you look in the tech archive, @Bull Bar Cowboy did an awesome V8 rebuild in great detail.

 

‘Thanks for the responses 👍

A few pics of the stripped block...

53ED5F00-2BFF-434D-BA4E-11828EF351A4.jpeg.8e74980d21010935836e1e6c83020fc5.jpeg

E336BCCA-1E55-4E0D-BE00-6790258C65C4.jpeg.620974c2f1c03601cf5771e117cb48ef.jpeg

9C95674A-AD77-4728-ACD1-0D2A67CA86B6.jpeg.e05e43297a5f1abc42dc1ddbbd8cffb7.jpeg

7BCBA44B-8348-49D6-B5EE-6421F4952F5F.jpeg.bea0f7b5bf8a9e5ad7412beb01c3d0d4.jpeg

EB958D41-2755-409C-AFCC-4A48CB9C1365.jpeg.50cf7b43d36e45eebcb79eaa36755f9f.jpeg

17EBE136-0C2E-4DE6-8C28-C5228E0EB110.jpeg.5a926fbd6f03dca92c81c822159e6db4.jpeg

 

The cleaning has started...

E82EEEC3-25A1-425E-9E33-5C90C139A78B.jpeg.6211003faefb91776b40602afe55946f.jpeg

2ED466F5-1CEB-48E3-9B2C-177769B76C5F.jpeg.c39c872803e3e6166fd7f31b958d39b6.jpeg

This was after two 20 minutes sessions in the ultrasonic cleaner and a toothbrush. 

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Yup, that's standard bore size, what mean was is there any ovalling or tapering of the bore?

If you are rebuilding an engine, you should be measuring this with a dial bore gauge at various points to see if it needs a rebore or not. Just looking alright is not good enough I am afraid.

of course if it needs a rebore, that's new pistons/rings as well - seeing you cleaning these made me assume you had measured up the bores....

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