Grinding Clearances for rod bolts on stroker 400

[TexasRoadRunner68]

After checking all my bearing clearances, my next step will be installing the crank, checking endplay and then marking and grinding clearances for the rod bolts. Its a 4.25 stroke 400-512 setup from 440 source. I still need to install the pistons on the rods, and have not yet filed them. After watching several videos about this, it seems some people mock up a bare piston on the crank and hold it to mark where grinding is needed, some appeared to drop in pistons without rings for mock up, and some looked like they installed pistons with rings and everything to mark with an paint pen.

For those that have done it, do you recommend the full mock up with rings? My concern is scuffing up the piston skirts.

And as far as all the shavings, did you just use the engine brush sets on oil passages, etc, or did you have it hot tanked again? The block is fresh from machining and has the cam bearings and freeze plugs. Its also nice and oily I'm sure, so those shavings might stick in places. The last thing i want is a ton of shavings going through the motor on break in trashing everything.





Thanks again for all of the help with prior posts, I have had some great advice from people on here and definitely appreciate the responses. I'm new to some of this, but I wanted to build my own engine from the ground up to learn and get better. And its just cool to have done it yourself lol.

 

[33 IMP]

Are you using the bbc con rods with your combo? You might not need to clearance the block at all. It's the big end of the bbm rods that cause clearance problems.
But if you do, I would hang one rod and piston, and use it without rings, mark your grind area, make your clearance, then pull it all apart again and clean it again from scratch.
Edit: no need to hot tank again, but do all the rest of the block cleaning. Can't get it TOO clean.

 

[MCODECUDA]

Just a word of advice in case there is ever a next time. Grind your rod clearances before you send the block out for machining using an old piston (rings removed) on the rod that you will be using.

 

[TexasRoadRunner68]

Unfortunately that wasn’t really an option

Just a word of advice in case there is ever a next time. Grind your rod clearances before you send the block out for machining using an old piston (rings removed) on the rod that you will be using.

Unfortunately that wasn’t an option this time, as I was waiting to figure out what bore diameter the block cleaned up at in order to buy the stroker kit. They still managed to screw up, and I had to buy another block that was good at 0.035 over like they initially advised…but that’s another story.

 

[beanhead]

After checking all my bearing clearances, my next step will be installing the crank, checking endplay and then marking and grinding clearances for the rod bolts. Its a 4.25 stroke 400-512 setup from 440 source. I still need to install the pistons on the rods, and have not yet filed them. After watching several videos about this, it seems some people mock up a bare piston on the crank and hold it to mark where grinding is needed, some appeared to drop in pistons without rings for mock up, and some looked like they installed pistons with rings and everything to mark with an paint pen.

For those that have done it, do you recommend the full mock up with rings? My concern is scuffing up the piston skirts.

And as far as all the shavings, did you just use the engine brush sets on oil passages, etc, or did you have it hot tanked again? The block is fresh from machining and has the cam bearings and freeze plugs. Its also nice and oily I'm sure, so those shavings might stick in places. The last thing i want is a ton of shavings going through the motor on break in trashing everything.





Thanks again for all of the help with prior posts, I have had some great advice from people on here and definitely appreciate the responses. I'm new to some of this, but I wanted to build my own engine from the ground up to learn and get better. And its just cool to have done it yourself lol.

What those guys said ˄˄˄˄....always do your grinding, de-slagging, oil passage enlarging or whatever before installing any cam bearings or plugs. But like you said, too late this time.. no huge deal you'll just have to be very mindful of where shavings might end up. Maybe mask off/cover any holes or passages where you don't want debris getting, even just stuffing rags everywhere and right around your work area will help. Try to leave only the area you're working on exposed (you'll still obviously want to go through it thoroughly afterwards).

Just for some reference, and yours may or may not need what mine did, but here's all the clearancing that was done on my 440/505 with chevy-size big ends---and on the one cylinder, there wasn't any touching of parts but it looked close so it got a little kiss. Could've honestly been fine just hitting the oil pickup boss, YMMV

 

[68 HEMI GTS]

You don’t need rings for mock up. 400/512 kid usually just needs a touch off the oil pickup boss.

 

[TexasRoadRunner68]

You don’t need rings for mock up. 400/512 kid usually just needs a touch off the oil pickup boss.

That’s good to hear. I had figured I’d be grinding for 3-4 rod bolts as well. I guess we will see. It would’ve been great to have had the crank and rods prior, but it wasn’t an option. In hindsight I should have just bought the kit and replaced the block if needed, which is what I ended up doing.

 

[dvw]

I always mock up without rings.
Doug

 

[TexasRoadRunner68]

I always mock up without rings.
Doug

Do the pistons need to be lubed at all or can they be mocked up dry?

 

[beanhead]

Not dry...a light smear of motor oil is fine.

 

[hunt2elk]

Which kit did you end up going with? I've been looking at them as well, but want a bit less compression ratio than what the kits come at.

 

[TexasRoadRunner68]

Which kit did you end up going with? I've been looking at them as well, but want a bit less compression ratio than what the kits come at.

I got the 0.035 over -24cc dish piston version. I think I’ll be 10.4:1 roughly. I know that’s a bit higher than some advised, but with aluminum heads on pump gas I hopefully should be fine. 93 octane is everywhere here.

 

[68 HEMI GTS]

I got the 0.035 over -24cc dish piston version. I think I’ll be 10.4:1 roughly. I know that’s a bit higher than some advised, but with aluminum heads on pump gas I hopefully should be fine. 93 octane is everywhere here.

It’ll be absolutely fine on pump gas. I have 2 - 400/512’s in the garage. Both Indy heads. Both run pump 93.

After you're done grinding a trip to the car wash is in order to blow it out good. Either that or an at home power wash.

 

[33 IMP]

Agree with 68 hemi gts. You should be fine on 93 with the aluminum heads, as long as you have a decent camshaft in it. 250° at .050 or so.....

 

[TexasRoadRunner68]

It’ll be absolutely fine on pump gas. I have 2 - 400/512’s in the garage. Both Indy heads. Both run pump 93.

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After you're done grinding a trip to the car wash is in order to blow it out good. Either that or an at home power wash.

Is there not a risk of rust on the machined surfaces if you spray it out with water?

 

[HawkRod]

Is there not a risk of rust on the machined surfaces if you spray it out with water?

Use COLD water and dry it immediately. With hot water, it will flash rust.

 

[68 HEMI GTS]

Is there not a risk of rust on the machined surfaces if you spray it out with water?

You have to get it dry relatively quick and get some WD40 on the machined surfaces. Any light rust you can clean off with a red scotch brite.

 

[Cranky]

I like to use ATF for the final wipe down of the cylinders and deck surfaces. It's very high detergent and if you use a diaper you will see the discoloration of dirt on it even after a final wash with water.

 

[GTXDAN]

Use a shop vac while your grinding to catch most of the shavings, then do the wash job like they say. You can never be to clean.

 

[StrokerSpanky]

I used a couple of small yet very strong magnets placed next to where I was grinding and they worked great. Still re washed with solvent and compressed air and brushes. I like the shop vac idea too.