1st time engine builder and the shit locked up. What did I do wrong?

[mofo]

I rebuilt my engine for the 1st time a 13b engine and while I roadtesting the car, the engine locked on me; not the transmission ,so what could be my mistake :banghead:

[moremazda]

You won't know until you pull it apart.

[mofo]

will find out tomorrow after work

[TitaniumTT]

You won't know until you pull it apart.

True story

[2gslse]

Sorry to hear about the engine/more downtime on the car
It could be anything but I would guess oil related (pickup fell off or losing oil out between the front cover and front iron)
post some pics when you tear it down.

[TitaniumTT]

& make sure you try to rotate it after each step to hone in on the problem

[RICE RACING]

I have built hundreds of engines since the very early 1990's and never had one seize or lock up, have seen ones that have though and all have been oil system failure related.

Oil pick up
No engine oil (oil line leaks, broken sump)
Oil pump drive failure (small key not installed ! or aligned properly)

Check the pick up when you take the sump off, check the oil pump drive, check the thermal pellet in the front of the E shaft, check the oil galleries in the E shaft (as I saw one that was blocked! and caused a front rotor to not get any oil and seize hard on the shaft. Look at everything in the oil system (look for oil in sump lol) and you will find the cause of why it "locked up".

lack of oil supply (flow and pressure) will be the only statistically most probable thing that will lock up a rotary, that and snapping the E shaft in half lol.

[TitaniumTT]

Edit - I missed the while rd testing part... I thought it was assembled and rotated.

The used locked up engine that I bought was built using a hodgepodge setup of S5 and S6 front cover pieces that didn't mix well and seized the front stat bearing to the e-shaft.

Make sure you take pics so we can determine the cause, or bicker about it like keyboard mechanics

[N.RotaryTech]

Make sure you take pics so we can determine the cause, or bicker about it like keyboard mechanics

:icon_tup: :lol:

[mofo]

Here's some pics of what I found out so far

[TitaniumTT]

Could be a number of things.........

First of all, did you prime the oil system before starting the car?
Second, are you sure all the front bearing parts were from the correct series?
Third, some shit left over in the oilsystem that got pushed out when there was oil pressure and fragged the bearing

[mofo]

I think that I will go w/the 1st answer, 'cause I know for fact that I did not prime the oil system.
Thanks

[RICE RACING]

In one picture the oil sprayer for the front rotor looks like it is wound out??? if this is so it will cause low oil pressure (could be the root cause).

It is hard to guess over the internet:

But next time:
* Ensure those sprayers are loctited in and tightened hard.
* Crank is 100% clean (oil ways).
* Lube all parts with petroleum jelly (Vasoline) lightly.
* Crank motor till you have oil pressure before starting it.
* Check function of thermal bypass in front of crank and make sure its installed correctly to.

Short of any foreign material or grossly out of spec bearing parts aside from other things I mentioned in my first reply you wont *touch wood* have anything of this sort happen again.

Good Luck with it all :)

[project86]

This is all good to know since im gonna be rebuilding mine soon. im also a building newb.

[mofo]

Thanks all you guys for your comments and I hope on my next one it wont be the same.

[TitaniumTT]

Could be an endplay/thrust bearing related issue that caused debris to get into the front main bearing and chew it up. Also the front main is the first place oil starvation shows up.

Assuming that he checked and set endplay, I'm still going with mixing and matching S4/5/6 front assembly bearings. One of the reasons I got my engine so damn cheap was because some "pro" level builder fucked that one up. Engine lasted a whopping 25 minutes.

I had a buddy who built his own engine at my place one time and it ran for 15 seconds then locked up solid. Come to find out he'd let the little oil pump sprocket key slip out when he slid the sprocket on. The oil on the bearings lasted 15 seconds. The pump probably spun long enough to load with thick cold oil, then due to lack of a key it slowed down or stopped while the sprocket continued to turn. Then the engine ran out of oil on the bearings and locked up.

Had a friend of mine do that too, that thing can be a bitch to get in properly, don't know why people don't check that before the cover goes on, also don't know why people don't prime the oil system.

I wait until I have 30+psi of oil pressure at cranking before I try to start the engine. I also pour oil down the oil filter pedastal, both holes, try to fill the oil coolers as much as possible with oil, and then spend a few minutes turning the engine over by hand to start the oil moving. Then I'll start cranking in short bursts until I see pressure, then the cranking gets longer but never going over 7 seconds until I have suffiecent pressure. Then prime the fuel system, and light the girl off.

This is also common practive for me if I haven't driven my truck for more than a week - I'll pull the fuel pump relay and crank until I see a little pressure, then put the relay back in and fire her off.

[need RX7]

I wait until I have 30+psi of oil pressure at cranking before I try to start the engine. I also pour oil down the oil filter pedastal, both holes, try to fill the oil coolers as much as possible with oil, and then spend a few minutes turning the engine over by hand to start the oil moving. Then I'll start cranking in short bursts until I see pressure, then the cranking gets longer but never going over 7 seconds until I have suffiecent pressure. Then prime the fuel system, and light the girl off.


Thanks for posting this :icon_tup:. I'll keep this in mind when I fire up my 'new' engine in the n/a. I probably would have just cranked it for 5 seconds and called it done and fired it up :rofl:.

[TitaniumTT]

Yeah, lots of people do and that's what happens. You'll be surprised how long it takes cranking to get oil throughout the entire engine, all the coolers, the passageways, the filter, the turbo's etc etc etc. Even when letting a car sit for an extended period of time oil drains out over time. Just a good idea I think. If you're changine the oil it'll take a full second if not a little more to pressurize everything. Benefit is there's still oil in all the journals, bearings etc etc etc so it's not all that bad.

We did put an accu-sump in my buddies Landi Tsi 300 though so as soon as he turns the key before the engine rotates there's a little pressure.