Racer X

I know it strengthens the engine but what do the builders do when pinning a engine?I always wondered what people meant by saying that the engine was pinned.



Thanks

Luis

93 R1

They put in dowel pins to hold the plates to the housings and keep the flexing minimal. Apparently its not really important cuz not alot of people are doing it. Most of the guys running in the 9-10 sec. range don't have it done, so you probably don't either

1Revvin7

Just one of those extra things to do, if you're gonna blow 5k on all new housings/parts, might as well go all out.

r_xplicit

that is why i had it done. cam at pettit suggested it, and well, it was ONLY 800.00 more....but then, i have that bit of security in teh back of my mind that the motor will hold the 30psi and that hopefully, one day, i might need the extra rigidity....



ll

Racer X

Thanks you guys I was wondering about that.

Judge Ito

Im not sure if this is going to help. But I have seen pinned engines break apart from some overboosting and detonation and I have seen some engines that were not pinned run some serious boost and properly tunned and not break anything. The trick is in proper tunning and using some nice strong side housings like the FD ones.

Fd3BOOST

Where exactly do they put the "pins" at ?



Are the stock dowel pins not enough? I dont get why you would want to pin it.

Judge Ito

The pins are installed in the area close to the spark plugs. In a piston engine boost will literally lift the head from the engine block and sometimes leak coolant. On a rotary engine combustion top dead center is on the sides of the engine. In the spark plug area. Basically the rotor housings try to shift or move from high boost or detonation. When this happens the rotor housings push on the factory dowel pins and the dowel pins break the SIDE HOUSINGS mostly next to the oil filter mount neck. Like I said I have seen engines with no pins run high boost and not break anything.

Node

It's the use of more of the stock dowel pins, there is one at bottom corner by the exhaust, and one at the top corner above the sparkplugs.

When I asked what this was, I was told people usually bore out the holes on the other corners of the engine and add 2 more pins so they are at all 4 corners.

Is this correct?

Judge Ito

I have seen people put the pins in all 4 corners. I really don't waste my time, doesn't mean dowel pins are not worth the extra protection. I pinned one engine because the customer request it. It was a solid billet pin from the begining of the side housing and finished with the last plate fitting very nice and tight over the billet pin. It was pinned close to the spark plugs.