Con rods hitting block..

[adds]

So I'm in the process of building a spare motor.

Straight to the point I have a 7 rib block, with aftermarket h beam rods and pistons going in.

I was just doing test fitment and I noticed when I turn the crank to just before TDC the side of the rods 1&4 hit the side of the bottom of the bore causing it bind up.

i could force it to spin around if I want so it's only just hitting.

(only had 1&4 piston and rods in but I'm sure all 4 rods will hit)

Has anyone else had similar problems to this ? having to notch out the bottom of the bore around 0.5mm so the rods clear.

[Big T]

Stroker crank or normal? It's quite common to have to clearance a touch with strokers.

If it's a normal crank, sounds like crappy rods that haven't been designed properly.

[Matt]

Show us a pic of the rods, could be u were supplied the wrong ones

[LittleRedSpirit]

Its not an uncommon mod, as for in this application I dont know. I do know fitting any aftermarket rod to a 2az requires notches like you describe, and a fair amount more than .5mm. Its not too alarming overall.

[adds]

I'll try get a pic up soon. They are spool rods.

normal crank.

[Jimmee1990]

Personally I like to have at least 1mm clearance between the conrods and the block, and the piston rings don't come near that close to the bottom of the bore so no issues there in grinding 1mm. Just make sure you properly chamfer the edges where you're grinding for clearance, it seems pretty logical but I've seen countless pistons damaged because this wasn't done properly.

Seen this plenty of times with Spool rods, they are just made a little on the wider side. TRD, Carrillo etc don't have this issue.

[adds]

Ok cheers just wasn't sure if somehow I had the wrong rods. All the measurements of the rods check out fine

I will ill start attacking it with the dremel!