9 replies to this topic

[111GSR]

Hey guys,

Can someone explain please the differances in these two engines ?
Is it only the flywheel bolt qty or is there a deeper differance ?


Thanks in advance.

[Adrian]

From what I understand 6 bolt has heavier\ stronger connecting rods and weaker pistons and compression is higher on 7 bolt motors. Also plenty of people will argue that 7 bolts are more prone to crank walk than 6 bolts. I think the heads on 7 bolts have smaller ports too?? But flow better???

[ONPSI]

Search is your friend This has been covered many many times before

[111GSR]

for some reason it gives me error in search no matter what phrase i use. . . .

[EVL20T]

Cranks are different, rods and pistons are different, head studs are different, water pipes are different, oil pump is different, intake ports are different

What do you need to know??

6 bolt internals wont fit in a 7 bolt block and vise versa

[Adrian]

Cranks are different, rods and pistons are different, head studs are different, water pipes are different, oil pump is different, intake ports are different

What do you need to know??

6 bolt internals wont fit in a 7 bolt block and vise versa

I thought vr4(6bolt) rods were a good upgrade for the 7 bolt motors??

[brisvr4]

I thought vr4(6bolt) rods were a good upgrade for the 7 bolt motors??

Nope, they are thicker at the big end than the 7bolt rods. You can use 7 bolt 2.3 stroker pistons in a 6 bolt block though if you use a 156mm rod with them. Gives you a much wetter rod ratio.
You can rev that combo pretty high!

[DOUGMO]

only if you order them with, or modify to take a 22mm gudgeon pin Tim

[brisvr4]

You can get the 156mm rods with the 22mm pin stock for 6 bolt now George.

[DOUGMO]

yep