Port matching with TVIS.

[Quint]

Considering port matching my 1ggte, heard many different sides to the debate, but it seems that with direct fuel injection, its all bonuses, correct?

Wondering what everyone elses point of view on this is?

Also, with the TVIS (or YVIS ? Yamaha variable intake system since its stamped all over with yamaha ) what effects does this have? Should the same method be used with the tvis spacer with dowels placed on either side to match to the head and to the intake manifold, the spacer seems to be pretty smooth and free of any casting marks etc.

[strx7]

Yamaha casts 90 odd percent of all of toyota's twin cam heads. they mightn't still do but in the 80s and early 90's they certainly did

[Trls250s]

Considering port matching my 1ggte, heard many different sides to the debate, but it seems that with direct fuel injection, its all bonuses, correct?

Wondering what everyone elses point of view on this is?

Also, with the TVIS (or YVIS ? Yamaha variable intake system since its stamped all over with yamaha ) what effects does this have? Should the same method be used with the tvis spacer with dowels placed on either side to match to the head and to the intake manifold, the spacer seems to be pretty smooth and free of any casting marks etc.

Depends if you go nato on it and take to much material out. But being as its force fed so long as all the ports are the same size i dont see problems with port matching.

But it would definately benifit you doing some extensive reading in this area. I have several books on engine blueprinting and port and polishing heads and they are worth purchasing even to just have on your book case and impress visiters.

Go on Amazon and grab "How to Build, Modify & Power Tune Cylinder Heads by Peter Burgess " its very good and covers the fundamentals and shows how to do it and only $16USD atm.

As for the TVIS question i dont quite understand what your getting at, are you asking if you can port the TVIS spacer itself?

[Quint]

From what i understand with port matching, you grind both the head and runners to match and drill holes to put dowels in the head, you then drill matching holes in the manifold so you can match the ports up exactly, as there is a slight 'play' in the bolts allowing the alignment to shift slightly when you are tightening them and unallign your head and manifold pretty much undoing your hard work, the dowels prevent this by holding the manifold in the correct position while you are tightening it.

Since the TVIS is actually a spacer 15-20mm thick, i'd have to match my manifold and head up to the spacer. What i'm wanting to know is; is it safe to do this with the spacer or not, as no books i've glanced at mention TVIS (not surprised).

Will look into that book though, cheers.