hello guys!



I have just done my first NA rebuild, a guycame to me with a 6port that had overheated, so he wantet a rebuild. i have just done rew engines in the past, but i thougt that was no problem. when i had pulled the engine apart, it came clear that the sideseals had made huuuuge grooves in the sidewalls, so i had to get new ones.



i changes all 3irons, all new seals and bearings, ported the irons just like the old ones and gave the engine a good wiew. the housings had some chatter marks, but not to bad, just around the exhaust port.



the changes from the old too the new engine is:



irons from a 6port with sleeves in housings ( the old one got them in the manifold)

2piece apex seals (old one had 3piece)

FD-bearings



sooo, the old engine gave a 170 rwhp, and the new one gives 125.... the curves look the same, but just lower...



it has a 51 weber, and prospark efitec ignition. nothing has been changed here, it looked to me a bit lean, but i have never adjusted a NA rotary, so i have no idea really..



the compression is not measured, but it seems healthy, starts and idles fine both cold and warm.



anyone know what can steal 45rwhp on a NA rotary?



its in a VW Beetle rallycross car, so its not using the sleeves for 6port, and anything egr.



thanks,stig

 

make sure, the engine is firing correctly on the leading and trailing side..and that both, leading and traling coils are actually working. if traling stops sparking, the engine will run fine using the lead plugs. but you will see a 12% loss of power.

 

after a good inspection and making sure everything was in order, we ran a some launches and 1/8 miles, with the numbers done and the numbers we had from last time the engine was rebuild shows that the engine is good, even better than last time.



it was a strange dyno session the owner told me, he didnt understand much of what the operator did, and that he didnt think the operator got full throttle under the pull...



then, case closed, and he is off racing in he's VW Beetle