Understanding your engine......Part I

[C4B]

I was talking to a rice-boy the other day (forgive me!) and he informed me that he was going to get his "heads" ported to get more power.....

On the surface this may seem like a perfectly reasonable thing to do, until you realize he was driving a 4 cylinder Honda (straight four...only one cylinder head!).

It turns out he didn't know what the head was, but that you had to get "them" ported to get more power. :eek: :confused:

[SPJ]

Bah stop picking on the poor guy lol

[Rt!]

why waste your time :)

[mosanator]

Wish i was his mechanic.................. :lol:

[SSbaby]

I would have thought that the Honda head was just about fooly developed, moit.

In fact, most Japanese NA engines are well developed leaving little value in spending the $$$ on aftermarket engine enhancements.

GM have a different philosophy on engines... they get detuned.

[Gambelli]

Its funny, back in the day, when I was a young'n, my friend had (didn't everyone!) a Gemini.

Anyway he was a member of the Gemini car club and was very impessionable so when he heard that someone had a "port and polish with a 30 thou shave" that was it, all he raved about from then on was a port and polish and the head shaved 30 thou, when I asked him, as I had no idea myself, what the hell that meant, he said he had no clue but everyone does it.

So in went his engine to have some work done, they charged him $2,000 and explained that they did the port and polish and shaved the head and a new cam and heavy duty springs etc etc etc.

Well from a passenger point of view, it went no faster, didn't rev as well, and topped out at 132kph rather than the 155kph he used to get, to this very day I still think they just changed the diff ratio and pocketed a handy profit.

But this was after all a guy who thought the difference between the 3.3 litre six and the 2.85 litre six was that the 2.85 litre six was the same size and power but only needed less oil, 2.85 litres to be exact!

[Ryzz]

.
But this was after all a guy who thought the difference between the 3.3 litre six and the 2.85 litre six was that the 2.85 litre six was the same size and power but only needed less oil, 2.85 litres to be exact!

:eek: I dont know wether to :rofl: or :bawl:

[VX_CALAIS]

Yea - I've got a mate with a honda prelude. Spent 2K on exhaust and POD intake - it went slower.. sounded louder than my car .... (a RAV 4 beat him). Put it back to stock for more power :lol:

[the mooch]

I didn't have a Gemini as my first car (pew!). Mine was :o (don't laugh) a FIAT 124 sport, twin webered 1600, ported head (only ONE! :D ) Alquati cams (like HSV to wog mobiles) 2 inch exhaust, shortened diff ratio. She used to dust off 5 litre Kingswood/commodes in a straight line, and slaughter them through the hills....................went it wsn't broke :( :( :( :lol: :lol: :lol:
You know they called 'em 124's because thats the only gears they had left in them usually!

[Danv8]

[QUOTE=C4B]I was talking to a rice-boy the other day (forgive me!) and he informed me that he was going to get his "heads" ported to get more power.....

On the surface this may seem like a perfectly reasonable thing to do, until you realize he was driving a 4 cylinder Honda (straight four...only one cylinder head!).

Poor bugger must of gotten confused with a head job from a 50cent whore.


:p

[cheffy]

After having done a few Jap car heads, they can be cleaned up a bit overall there isn't that much to be gaines. Its mainly deburring the cast marks and taking the valves out to a 5 way angle job that makes the difference. Very little is done in the way of reshaping hte heads. As a side note. On My F3 engine the head is virtually stock in appearance but makes 210bhp through a 26mm air restrictor. I had a head ported (enlarged) and it actually went slower.

Similar story on MX5's. Changed the exhaust on one only to maake an extra .5rwkw.......

[Martin_D]

My 1598cc Honda Improved production race engine used to make 122fwkw @ 9100rpm. Obviously this benefitted a lot from a properly ported and flowbench developed cylinder head....as any engine combination will. Those that go backwards havent got a handle on the basics. Port velocity anyone?

[Gambelli]

My 1598cc Honda Improved production race engine used to make 122fwkw @ 9100rpm. Obviously this benefitted a lot from a properly ported and flowbench developed cylinder head....as any engine combination will. Those that go backwards havent got a handle on the basics. Port velocity anyone?

So was it a 30 thou shave mate, huh? huh? me mate will be so happy to hear that.....

I'm not having a dig BTW I'm just sitting hear smiling to myself reminiscing of hearing those words "I cant wait to go in for a portnpolish and a head shave 30 thou".....Funny times!

But who am I to critisize I was years away from getting my own car at that stage.

Oh, one more anecdote (I had a very knowledgeable circle of friends back in the day) We were sitting around one Saturday night, again my 2.85 litres of oil carrying Commodore friend was there, as was another of his friends. This other friend had one of the new fandangled 1.3L 3 door TS Charades when they first come out, anyway this guy's 1.3L Charade with cannon could outrun anyone, just ask him, but he told us of an interesting story.

Aparently the only car that ever saw him off was a heavily modified Cordia Turbo.....

"Faaark, we took off and I got the jump on him but when he changed to second he had it set up for turbo boost and he shot past....."

We quizzed him on what he meant by he had it set up for turbo boost and he told us...

"the guy in the Cordia had a turbo on second gear"

Umm we said, turbos don't work like that....

"Yes they do everyone I know with turbos has one on second gear, you can flog him in 1st and 3rd but 2nd you can't beat them"

Ahhh thats because of whether or not they are revving the car out and/or hard, a turbo comes on boost at certain revs not gears!!!!!

"Bullshit mate you calling me a lair?????"

No.....just a F-Wit......

Oh yeah! he, at the tender age of 20, finally got his 1st ever girlfriend, anyway she didn't like the Charade, she liked those lovely little Suzuki X90's (back when they first come out) She agreed that if he traded the Charade on an X90 she would spend the weekend with him up at the Hydro Majestic and let him have his way with her (finally!) he did so of course, after all 20 years would I guess be a long time to wait, he then claimed, in defence from the laughter of all his mates, that the X90 absolutely flies and that it put the Charade away easily! Funnily enough I had a GTi Swift at the time and took him for a drive but he never did take me for a spin in the X90, which he claimed was much quicker than the GTi.....

.....I sure hope the sex was atleast good, then again, stuff him, no I don't......

Sorry for the long post but jeez I had some dickhead friends....

[VXEXEC350]

Port velocity anyone?

Yes thanks, I'll bring crackers and cheese. :lol:

[Drizzt]

So was it a 30 thou shave mate, huh? huh? me mate will be so happy to hear that.....

I'm not having a dig BTW I'm just sitting hear smiling to myself reminiscing of hearing those words "I cant wait to go in for a portnpolish and a head shave 30 thou".....Funny times!

But who am I to critisize I was years away from getting my own car at that stage.

Oh, one more anecdote (I had a very knowledgeable circle of friends back in the day) We were sitting around one Saturday night, again my 2.85 litres of oil carrying Commodore friend was there, as was another of his friends. This other friend had one of the new fandangled 1.3L 3 door TS Charades when they first come out, anyway this guy's 1.3L Charade with cannon could outrun anyone, just ask him, but he told us of an interesting story.

Aparently the only car that ever saw him off was a heavily modified Cordia Turbo.....

"Faaark, we took off and I got the jump on him but when he changed to second he had it set up for turbo boost and he shot past....."

We quizzed him on what he meant by he had it set up for turbo boost and he told us...

"the guy in the Cordia had a turbo on second gear"

Umm we said, turbos don't work like that....

"Yes they do everyone I know with turbos has one on second gear, you can flog him in 1st and 3rd but 2nd you can't beat them"

Ahhh thats because of whether or not they are revving the car out and/or hard, a turbo comes on boost at certain revs not gears!!!!!

"Bullshit mate you calling me a lair?????"

No.....just a F-Wit......

Oh yeah! he, at the tender age of 20, finally got his 1st ever girlfriend, anyway she didn't like the Charade, she liked those lovely little Suzuki X90's (back when they first come out) She agreed that if he traded the Charade on an X90 she would spend the weekend with him up at the Hydro Majestic and let him have his way with her (finally!) he did so of course, after all 20 years would I guess be a long time to wait, he then claimed, in defence from the laughter of all his mates, that the X90 absolutely flies and that it put the Charade away easily! Funnily enough I had a GTi Swift at the time and took him for a drive but he never did take me for a spin in the X90, which he claimed was much quicker than the GTi.....

.....I sure hope the sex was atleast good, then again, stuff him, no I don't......

Sorry for the long post but jeez I had some dickhead friends....


My turn of rthe long post now.

I had a stupid friend who for his first car, his folks bought him an early 80's GX Pulsar. Now this friend wasn't the brightest and did the following:

Tried to remove those stripes on the side of the car by scrubbing it off with steel wool. He scrubbed a gash down each side of the car which had reasonable paint for it's age.

He tried to tell me and another mate that his stock as a stock pulsar kept up with a blown 5L maloo at the illegal drags. :limpy:

He bought a turbo kit off an ET Turbo and bolted it up to his car. It worked reasonably well until he wound out the wastegate rod and blew the heads. :slap:

He was given a set of 14" alloys off another mate's pintara and he couldn't get them to fit without rubbing so he took to the offending part with a hacksaw. It turned out he sawed through one of the suspension struts.


We all had great laughs at his expense when we were younger. I won't even mention the ting his friend got up to with regards to computers and elecrtonics as it'd surely make you cry.


Drizzt

[payaya]

how ya know he doesnt have a lisp (sp)?

[Drizzt]

how ya know he doesnt have a lisp (sp)?

Who?

(1. The message you have entered is too short. Please lengthen your message to at least 10 characters.)

[Dickie Knee]

On the old 179 HT Holden ( all my mates had Holden 6's not Gems ) I just painted the head yellow one weekend.

All my mates that drove it said they thought it went better with the "new Yella Terra head" on it.
:lol:

[cheffy]

obviously port velocity is essential. However in our circumstances we have a rev limiter of 7000 and a inlet port restriction of 26mm. ZZTherefore we made the head ports to big lost air velocity and walah, One f**ked race head. (Good for a 2l supertourer though.) The heads that are being sold by tuna though have a great advantage in that the port flows are going to be near identical for each cylinder creating a good engine balance...

[the mooch]

I knew a bloke who years ago rebuilt a 253 for a VH Commode. When he put the pistons in the block he lined up ALL the ring slots with each other. Then he wondered why his rebuilt engine was blowing so much smoke.......... :bash:
No better than another mate who, after being told by his older brother to "do up the spark plugs hand tight" after checking the gap on his 186 HR did exactly that; did them up with his hands (no spanner). His brother couldn't understand why the old girl used so much fuel and went like crap on a run through the South East. :mad: Said mate went on to be a mechanic :eek: