Power loss after engine repair

[NSX-Racer]

Bad surprise after my latest engine repair (new head gaskets, new timing belt, removing A/C compressor) at the last track event this year: Engine reacts to the throttle not as quick as before, water temp goes into red zone after 3 laps with ambient temperature of only about 15 degrees C, peak power seems to be about 100 HP less (Civic Type Rs and Integras were faster at the straights) than before, feels like Vtec doesn't kick in, but revs up to 8000 without a problem.

Possible causes: Timing belt mounted wrong (not much likely because I drove about 200 km without damage)?, camshaft sensor failed?, engine head mounted wrong?, any issue with the Vtec control?

Mechanic checked hoses and electric lines at the track, didn't find an error but will of course make a major check back in his shop.

Any input is welcome.

P.S.: You may watch an in-car-video proof where you see that I can follow an Integra in the corners but not on the straights (it has an engine with about 220 hps) here: http://www.fastvoice.de/Anneau2004.mov

 

[Larry Bastanza]

I think the things to do is check compression, bleed coolant, check timing belt and see where that leads you.

HTH,
LarryB

 

[NSX-Racer]

I think the things to do is check compression, bleed coolant, check timing belt and see where that leads you.

HTH,
LarryB

Is it really possible that the timing belt is - let's say one tooth - off and the car still runs 200 km/h?

 

[Procar Specials]

Because its too technical, I have to write it into my mother language.
Sorry.

Möglichkeit 1
Check die Einstellung des Zahnriemens gemäß Werkstatthandbuch, Markierung mit OT.
Die Markierungen müssen genau übereinstimmen.
Wenn das nicht der Fall ist, Neueinstellung.

Wieviel wurde der Kopf geplant ?
Meistens fehlt anschließend ein halber Zahn am Nockenwellenrad,
das muß entweder durch einstellbare Nockenwellenräder oder durch Einstellung auf spätere Zündung (nicht früher!) kompensiert werden.
Das würde auch die Überhitzung erklären.

Möglichkeit 2.
Hast Du Katalysatoren installiert ?
Es kann sein, dass einer von Ihnen durch die Hitze und das Wasser zugegangen ist. Bitte von beiden Seiten prüfen.

Falls Du nicht weiter kommst, NSX auf den Trailer und zu mir.

PROCAR

 

[NSX-Racer]

Danke, Detlef - cats were removed long ago - timing belt and ignition will be checked - I will forward your info to my techie.

 

[hlweyl]

Could be an air pocket in the coolant. Try jacking the car up in the rear and re-bleed.

How did the compression check look? Were the block and heads checked with a straight-edge before installing new head gaskets?

 

[Larry Bastanza]

Usually the timing belt off a tooth will make the idle sound like a V-8, kind of throaty. And it will be down on power, however the water temp is classic of a head gasket or poor coolant bleed. Good point about the head and block being checked for trueness during the head gasket replacement, but I am hopeful this is normal for your tech.

This is an 3.0 ODBI car, correct? I know you probably would have mentioned it, but any check engine light?

HTH,
LarryB

 

[NSX-Racer]

Larry, it's a '98 cp., so it's a 3.2 l. I have no engine check light (although the bulb works) and had no error code.