Ported heads and intake gaskets ?, FI J tubes too? Options

[Brotherbob]

I have some fairly heavly ported heads I plan on using.
The intake gasket covers up a great deal of the port work so my guess is you shave those gaskets to fit ?
And has anyone ported the stock FI j tubes a bit ?
Its a 1700 72 914. (IMG:http://www.914world.com/bbs2/html/emoticons/screwy.gif)

[SirAndy]

QUOTE (Brotherbob @ Oct 7 2005, 04:01 PM)

so my guess is you shave those gaskets to fit ? And has anyone ported the stock FI j tubes a bit ?

yes and yes ...

use the thick FI intake gaskets and match the openings to the heads. the stock runners can be polished but there's not a lot of material to actually port them much ...

i don't know off-hand if the 2.0L had bigger OD runners, if so, you might want to look into mating those to your 1.7L heads and plenum ...

(IMG:http://www.914world.com/bbs2/html/emoticons/smash.gif) Andy

[Cap'n Krusty]

The runners, even 2 litre ones, are gonna pretty much negate the advantages of the porting work you did. The runners (length and diameter), the plenum, and the small throttle body keep the flow as it is, ported or not. The Cap'n

[Bleyseng]

(IMG:http://www.914world.com/bbs2/html/emoticons/agree.gif)

The 1.7 are smaller so maybe you could gain alittle if you use the 2.0L runners along with a vanagon 2.0l TB which will fit a 1.7 plenum.
What cam are you using as that will determine weather any of this matters?

[Brotherbob]

Ok so I shave the gaskets and the forged end of the J tube could be opened a bit but if its all for not ? I have a cornicapia of parts to assemble the engine and have no idea about the cam. It appears this short block has had some work , oil cooler set for external, deep sump,nice and clean. Its gonna be mated to these ported heads that came along.
I do however have bone stock heads I could use if it would perform better with stock 1.7 FI ?
This is a very low budget car for me, I have 2 914s to build one and have been resembling the mad scientist out in the barn!
I am walking with out a net except for the Pelican site which has been very helpfull. Hell I dont even have a book on it but its coming together . (IMG:http://www.914world.com/bbs2/html/emoticons/screwy.gif)

[IronHillRestorations]

Opening up the cast end of the intake plenums isn't going to help much of anything. The intake runners are long, and there isn't anything you can do to the tubes to open them up. Also there's so much air in the intake system at one time, you really can't gain much from grinding out the intake or the intake port.

The other thing is you really have to be careful when you start changing the vacuum dynamics of the intake system, as it is a controlling factor in the injection system.

If you've got two 914's to deal with, then trying to squeeze half a horsepower out of a 1.7, isn't worth the trouble.

[sean_v8_914]

I have some pop up 1.7 pistons (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

[Brando]

Ideally you'd want new intake runners that are the same diameter as your ported heads. Going with something like that though would probably be pretty damn expensive trying to get it all done right.

[Bleyseng]

Do the ported heads have bigger than stock valves? Just porting 1.7 heads with stock valves isn't going to do much.....

Install a better cam than stock, now that will do something

[Brotherbob]

Now you guys have got me thinking carbs!! (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)
I assume the cam is hot with everything else that has been done so ported heads do " dittly squat" with stock FI. Hmmmm carbs sound better?
I have a complete Fi set up. shit. Its not like Im building a show car here either.Oh and the valves are bigger in the ported set ,Now whatta I do .

[davep]

Jake has been saying that the intakes pretty well flow good enough for the engine. The real problem is with the exhaust ports. More than that, the whole horsepower thing relies on the package deal: just changing one thing or two will do next to nothing. Every part must be matched to come up with the correct combination.

[Bleyseng]

You need to figure out what the cam is or just change it to a a good cam, anything but stock.
Ray Greewood runs a 1.7 with the popup pistons, 42x36 valves, and a better cam. Results are about 95hp!This is with Djet FI.

The cam is the key, along with proper valve sizing, compression ratio, deck, etc to get anywhere witha type 4 motor.
Yes, the exhaust needs improving but a longer duration exhaust valve timing really helps along with a bigger than stock valve (33mm)

[bd1308]

QUOTE (davep @ Oct 8 2005, 05:29 PM)

Jake has been saying that the intakes pretty well flow good enough for the engine. The real problem is with the exhaust ports. More than that, the whole horsepower thing relies on the package deal: just changing one thing or two will do next to nothing. Every part must be matched to come up with the correct combination.

it's all in the combo ™

-Jake Raby