Georgethefierce

I have an '84 that I use to run IT7 with the SCCA and I'm not having much luck. I purchased this "fresh" rebuild as a long block after losing 2 other motors previously and I'm looking for a "why" on this one and also to see what can be salvaged.

This motor lasted exactly 1.5 sessions, it never made any power and was basically crap from the get go. I decided to tear it down to see what may have caused any issues and basically found the rear rotor bearing seized to the eccentric shaft which makes me think an oiling issue...the oil pump and chain looked fine but I'm new to these motors and I'm not sure where else to look. In the mean time I cleaned everything up and I'm a little disappointed in what I found and I am skeptical of re using either housing or rotor.


first, the housings themselves appear to be different, with the rear being an "H" housing and the front being a "Square" I have no idea if this is OK or not so opinions would be appreciated.





second, the housings show some flaking and wear to the surface

front





rear








the rotors themselves don't look great but I am not sure if this is an issue or not








the ones thing I am sure of is that the rotor bearings aren't good.







and of course the eccentric shaft is now junk





so, I'm looking to put together a motor for this season and with parts incredibly difficult to find I am looking to possibly salvage some of what I have and for places to check to understand why this particular motor lasted such a short time. (it was running down on power but had high oil pressure (80+ psi and then lost oil pressure and never ran again).


Thanks for any and all help you guys may have for a n00b.

Jeff20B

iTrader: (13)

Can you post any zoomed in pictures of your intake manifold? I want to see what they were trying to accomplish. Thanks. The carb too if you have any pics.

Looks like that engine was over-revved. I'd look for another set of rotors and a shaft. Stat gears too, maybe. Then I'd slap some Atkins apex seals into those housings and keep going. Atkins seals break in well on missing chrome like yours. And since you can't get new 12A housings anymore, your housings are in excellent shape!

Georgethefierce

not sure how it would have been over-revved, I kept it well under 7k while I was on track.

I'll try to grab some pics of the intake and carb.

t_g_farrell

iTrader: (1)

What kind of failures did your previous engines have and what is the frequencies of those?

Maybe you are doing something wrong here thats not obvious. I've known people to run engines
for a whole season before being rebuilt.

Georgethefierce

the first engine lost the front oil o-ring and spun a bearing, that one took out the rear housing. the 2nd one just smoked alot, we suspect a bad oil control seal but it ran great up until we pulled it, it just used oil and the flaggers had grown unhappy with the smoke screen.

This one just was never right...WAY down on power from the get go and all kinds of issues starting and idling....I expected to see that it was put together incorrectly but I see nothing that stands out.

and yes, we should get multiple seasons out of a rebuild, IT7 is a very mild prep class.

t_g_farrell

iTrader: (1)

Whoever you get your engines from needs a talkin to. LOL