2G rods in a 1g?

[justinh722]

I had a 7 bolt motor that ended up throwing a rod through the block. It had forged Wiseco pistons in it and the number 3 piston is shot as well as the rod. The other 3 pistons are still in decent shape. Pistons and rings have roughly 200 miles on them from the previous owner not properly rebuilding the engine.

I have a spare 6 bolt block that was rebuilt by sparry race engines and the kid assembled it wrong and burned a hole in the piston after about 5 minutes of run time. The cylinder looks ok though. Can I use the 7 bolt wiseco's in this 6 bolt with the 2g rods or should I use the 1g rods? I haven't really checked out the rods to see if they are forged or stock ones. Also, can I use the ARP 7 bolt crank cradle on the 6 bolt?

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[bryanwheat]

You will have very excessive side clearance on the rods if you use them on a 6 bolt crank. you are better off to buy a set of 6 bolt rods and have the small end enlarged to run the 7 bolt piston.

 

[turboglenn]

Yea, complete downgrade...get 6 bolt rods and have the pistons machined for the larger 6 bolt wrist pins..the weak link is 7 bolt rods being smaller compared to 6 bolt "big rods"

and the rods in the pic are stock 7 bolt

putting 2g pistons on 1g rods is common and any machinist can do it.. but just buy some eagle h-beams for 300 bucks if ya can..also DO NOT re-use the rings..pistons will be fine if the piston to wall clearnace is good or can be machined to be good (within spec is what i mean by good)

 

[bryanwheat]

Yea, complete downgrade...get 6 bolt rods and have the pistons machined for the larger 6 bolt wrist pins..the weak link is 7 bolt rods being smaller compared to 6 bolt "big rods"

and the rods in the pic are stock 7 bolt

putting 2g pistons on 1g rods is common and any machinist can do it.. but just buy some eagle h-beams for 300 bucks if ya can..also DO NOT re-use the rings..pistons will be fine if the piston to wall clearnace is good or can be machined to be good (within spec is what i mean by good)

The 7 bolt rod has a 1mm larger wrist pin than the 6 bolt.

 

[turboglenn]

ooops you're right,, have the rods machined gfor the 2g pins, sorry been up all night no sleepy yet

 

[danielbo91]

I would used 6 bolt rods in the 2g pistons just have them machine to make them work, but if you dont want to spent money new set of rods i have set 6bolt rods sale pm me if you want them.

 

[justinh722]

I have a set of 1g rods and pistons in this spare block that was rebuilt. My goal is to hit around 600 hp and I don't think the 1g rods can handle that can they? Thinking about running a GT35r or something similar.

I have a set of ARP head studs that have only been torqued twice for the 7 bolt. I may just use them on the 6 bolt block with the 7 bolt head since I heard they were ok to torque 3 times. If I go with some eagle rods and these 2g wiseco's in this 6 bolt block, what could I push the block to horsepower wise? Thanks for the replies.

 

[brian9397gsx]

Cant use the arp head studs either 7bolts are smaller, head will be fine.

 

[92AWDHX40]

What kinds of turbos have you looked at to run with the set up you have? I would upgrade the pistons, and rods several options in that case.

 

[bryanwheat]

good luck finding eagle rods that fit a 7 bolt piston and a 6 bolt crank.

 

[92AWDHX40]

Ive been looking for upgrades to my stock setup vendors have some nice deals on piston, rod set ups.

 

[97-TSi-Hx35]

People have been putting 1g rods on 2g pistons for over a decade...

 

[justinh722]

I have been thinking about getting the gt35r turbo. Local guy is sellin one for 500 obo or i thought about going with a holset hx35 or 40. Will these 2g wiseco piston's on the 1g rods hold 6-700 hp?

I thought the arp head stud differences were just the hole sizes in the heads. So how come the 7 bolt studs won't work on the 6 bolt with the 7 bolt head?

 

[bryanwheat]

I have been thinking about getting the gt35r turbo. Local guy is sellin one for 500 obo or i thought about going with a holset hx35 or 40. Will these 2g wiseco piston's on the 1g rods hold 6-700 hp?

I thought the arp head stud differences were just the hole sizes in the heads. So how come the 7 bolt studs won't work on the 6 bolt with the 7 bolt head?

it's all about the size of hole in the block. 7 bolt's use a 11mm stud, 6 bolts use a 12mm stud. Imagine how well a 11mm stud will hold in a 12mm hole.

 

[92AWDHX40]

I had a 2g head for cheap but decided to use my 1g, simpler that way.

 

[justinh722]

Thats the thing, I have 2 spare 2g heads and a 1g n/a head. Im looking to keep my assembled 6 bolt engine to rebuild but would also like to build another 6 bolt from spare parts.

 

[92AWDHX40]

Well you have options.