ALFAGTV6.COM

[kevin]

Putting belt on requires attention even with cam blocks as you need someone to hold the left ex pulley so you can pull the belt firm all the way to tensioner so you get even tension when you adjust. I find you get a loose side. Sadly the standard 24v cam blocks dont fit perfect for gta cams and the cam can move fractionaly which creates an uneven tension when tighten the pulleys(i dont use key ways). All small things to make sure once you have your perfect set up that you dont screw up when tensioning belt. Again mentioned before you must have solid lifters for high rpm.

[kterkkila]

Let's see if belts hold on longer with this arrangement.

[kterkkila]

Almost done.


Hurricane Racing used bottom plate to add some rigidity on the block and on the main bearing caps. Is that really needed? Have anyone heard about failing blocks or other problems related to that? Any experiences?

[Giuliettaevo2]

This is an impressive setup!

The Hurricane engine used a drysump which also acted as the girdle plate. the nuts from the mainbearingcaps came through the sump..

If it's needed i don't know but it won't hurt either... how much rpm are you looking for?

[kterkkila]

Up to 10 krpm would be nice.

If making reinforcement and new sump, the dry-sump would be natural step to take. If not going to that, then original oil system might do the job, or nobody knows really, or does?

[kterkkila]

Have someone done stress analysis for the rod bolts? If running 72.6mm stroke and 10 000 krpm with let's say 30% lighter piston, how strong bolt are needed? Pistons get over 5000 g's, it's simple to calculate forces from that, but the rest of them aren't that straight forward..

[Mats]

How often do you want to rebuild?

[kterkkila]

Hard question. Prefer never, but after 10 hours on full speed on race track could been hardly tolerated. There are 3/8" and 7/16" bolts with 220 000 psi and 260 000 psi ratings available, but should know the forces first..

[Zamani]

Kterkilla,

I don't have much info, but just want to add that one engine which was built using the standard alfa oiling system didn't like 7800 rpm very much. Main bearings didn't last. So you may not only face component strength issues, but the wear on load bearing surfaces may be an issue too.

[kterkkila]

Thanks Zamani, all these pieces of information are needed. Naturally there are arising few question about what really happened on that engine. I assume it was in good condition, but what kind of oil was used, and was it on rwd car with rwd oil pump, or fwd car with cam belt or chain driven pump?

[Zamani]

I don't know the exact details, but I think it was all stock Alfa bearings, crank, RWD setup oil pump (164 block so it was belt driven). I cannot speculate more because the engine builder only told me that the bearings didn't last. i don't even know what didn't last means, 1 year, 2 years? However take into consideration that for an engine like mine where the pump is not spinning as fast as the 164 pump, 7000 rpm seen regularly, it's 6 years old and going strong (my oil pump's tolerance was within spec). However I can't imagine your oiling system is going to be anything close to stock right? Dry sump?

However JimK did mention that he paid special attention to his oil pump when he rebuilt his V6 and it was better than stock (maybe in flow capacity?)

[kterkkila]

RWD setup oil pump (164 block so it was belt driven).

If he used std RWD mesh on that pump, it could be the reason for what happened. I will go on dry sump if needed, but I'm not sure if that's must or not. Std pump might be good with small modifications.

[killaz]

What would be those small modifications?

[kterkkila]

I assume that the pump starts cavitation at certain speed. That can be cured by helping flow to pump. The 75 oil intake mesh looks extremely restrictive. Somebody should start a project and build a test bed for test running the pumps

[Maurizio]

something like this... http://www.youtube.com/watch?v=Ny9xl7iWayU