Question: If you blow your apex seals, would that lead to no compression?

 

Yes.

 

So it may be my side or cornerseal is shot?

 

Your rotor housing may be in bad shape too.

 

Could be any of the seals on the rotor (except the oil control rings), but, apex seals, corner seals and side seals all hold compression. If ANY one or more of them is failing, you can get bad compression.

Whats the history of this motor?

 

The motor was a Atkins 13bt street port. It blew within a 100 miles of installation due to a faulty oil pump. I sent it to a 3rd party company to get rebuilt because I wanted answers. Anyhow, it was a inexpensive rebuild. No biggie, just trying to get a idea of why it may have lost compression before I tear it down.

 

I figured if any of the seals were shot, you'd have lower than 60 on the front...I'd guess the housing might be in some bad shape.

 

Or 100miles wasn't enough to fully seat the new seals into the old housings. I typically go a full oil-change before making any judgements on a rebuild.

EDIT: I'm not saying you had a choice, with the bad oil pump and all.. do you think atkins put a used oil pump on?! Thats scary.

 

I noticed several months back when I did a compression check, the front rotor was a bit low. Under 90psi. I was told, "Needs more break in". So, I have been doing so. The engine had a couple thousand miles on it until Saturday.

Atkins made a honest mistake, shizzle happens.

 

i'd say take it back to atkins.... they warranty any rebuild for one year or 12k miles, whichever comes first.

 

Probably shitty Atkin's seals.

I lost a piece of an Atkin's seal 300-400km's into my last rebuild.

 

I did not take it to atkins to get it rebuilt after the Oil Sending unit wacked out on me. That is where it came from, but out of frustration I sent it to a 3rd party to rebuild it instead.

 

That hurts alright.

 

ok so after the whole oil sender thing..... the other shop rebuilt it?

they might have stole your atkins seals and put in some crappy old ones.... my dad had this happen to him on his 12A rebuild. took them to court, and the stipulation was to provide him with a brand new motor since the crap ones they replaced tore the heck outta the housings.... he basically got brand new 12A rotors and rotor housings, with all new seals and such.... the irons were ok


i had atkins seals on my first rebuild, that a local rotorhead did for me, still running strong in my friends car.....

 

Yeah, that whole "atkins shitty seals" thing doesn't sit well with me. I had great experiences with them. I think its a good way for people to blame poor engine building on somebodies seals.

No offence ClassicAuto, I'm sure you know what you are doing.... But, so does RotaryResurrection/Kevin Landers, and he still uses them in all/most of his builds. I would imagine that most engine builders wouldn't use them if it was only a couple more bucks for a quality seal. If I was using used housings on my rebuild, I would definately use atkins seals. Since I have brand new housings, I'm opting for OEM seals since I already have a set.

 

try running MMO oil in the front rotor. you could have a stuck seal. try taking off the exhasut and physicaly feeling each seel. take a 19mm and turn the engine clockwise feeling each of the front rotor's springs and apex. use carb cleaner as well to posibly help it out.
remove your plugs when doing this.
turn it over a few times to get all the crap out. then put plugs back in. run it for a while then check compression again

this could remove carbon that could posibly be effecting compression on the front rotor.

 

I get about the same reading off all three faces. 65psi.

Funny, I have been chasing a "Tick" in my car for months, MONTHS. I checked my compression a while back and the front rotor was not hitting much above 80psi. It had only had 1000 miles after breakin on it, so a few people told me the seal may not have set yet. I have to wonder if one/some of the seals had been failling on me already. The other day I pushed it too far I guess. I raced a Turbo Carerra and it was after that I noticed a bad idle. Got good fuel and all the supporting mods for 12psi, but I will know more when I tear it down.

 

None taken.

I know Kevin builds engines, and knows alot about them. Also that he uses plenty of Atkins products. He also builds thousand dollar engines. I'm sure if there were a cheaper product that "worked" Kevin would use that also. Nothing wrong with that at all - but I've never seen/heard of a casting failure on an OEM seal. I'm sure he's (Kevin) seen casting faults in Atkin's seals on occasion - this is what mine had without a doubt in my mind despit what Dan told me about the seals we sent him from my engine.

The only reason I used them was what you've mentioned (other people seem to have success with them) and price. Turned out to bite me in the *** though....

The problem is its not a couple more, its several hundred more. I'm running strong on OEM housings and OEM seals now.


Sorry for the minor hijack - but had to state my position

EDIT: and the "shitty Atkin's seals" comment was meant in the context of "shitty batch" "shitty bunch" or any of the variations of that, not shitty seals in general since people *do* have success with them - I'd just never personally trust those seals again.