Now Monsta 01's 160j sss

[Monsta01]

I have decided that im going to build an L17, 1600 block with 1800 crank, 1688 cc I am planning to run a closed chamber 210 head so 38.5 cc combustion chamber but will skim to make it approx 31.5cc, will install bigger valves and port and polish the head to suit good torque, factory pistons and rods, franklin cam grind stage 3 or 4 and double valve springs, approx compression ratio 10.3:1 with port matched intake manifold and twin sidedraughts and port matched headers and 2 inch exhaust. What do you guys reckon? Does it sound good and what about power levels?

[classicdat]

Sounds like a lot of work and going by the numbers might not yield much more power. General rule, longer stroke with smaller bore equals less revs, particularly with a shorter rod. The more conventional way was always to use the L18 Block.
That said a well built motor can be very rewarding, What do the books say to use, and with what cam combination?

[Monsta01]

Sounds like a lot of work and going by the numbers might not yield much more power. General rule, longer stroke with smaller bore equals less revs, particularly with a shorter rod. The more conventional way was always to use the L18 Block.
That said a well built motor can be very rewarding, What do the books say to use, and with what cam combination?

Maybe im best to stick with what ive got? Uhm i dont have any books im just going by knowledgevand thoughtva 1700 wud b cool i know it wouldnt rev as well but wth alot of town use aswell as open road torque would be nice, cam probably wud be similar to what im currently running so advertised 287 degree duration. The engine i have is great maybe i just need to be happy with what i have, i just wasnt overly interested in the numbers at the time of when i built it ie compression ratios and valve sizes, port sizes etc and now i am.

[classicdat]

So why not build a good head for what you have?

Well firstly i reckon it goes amazingly like really good but always want more power haha,

You can spend a lot of $$$ and in reality get no return - if it already feels amazing. In my mind enjoyment is the biggest return.

[2 doors]

So why not build a good head for what you have?

Well firstly i reckon it goes amazingly like really good but always want more power haha,

You can spend a lot of $$$ and in reality get no return - if it already feels amazing. In my mind enjoyment is the biggest return.

This is really good advice, between the head and the cam, this is where your power comes from, many gains can be made here, and you can still enjoy your car while the head work is being done, its an easy upgrade that wont require the engine to come out either, just make sure the cam and the head are both modified to work together, and re-tune the carbs to suit, the 1600 is a very good motor and responds well to good port work.

[Monsta01]

Can anyone help me? When my car was on dyno it did this a few times once it got hot and we couldnt explain it, fuel pressure and flow good, air flow good im stuck for ideas, when it didnt do it i ran 65 kw when it did it spikes to about 80kw help!

[2 doors]

could it be a dyno problem ? like maybe its loading up or something, how did the car itself behave? any backfiring or anything.

[DJZ]

That's a weird looking dyno chart! It does start to go lean around the 88kph mark, then richens up slightly between 105 & 110 then goes lean again after that. I would think that if it was a spark problem there would be rich spikes, I'd guess a carb problem maybe? Would be interesting to see a plot of the RPM vs. road speed.

[2 doors]

I know bugger all about dyno charts etc, but are the circle things on the charts indicative of gear changes?

[DJZ]

Yeah I thought that too but the number of bumps would mean he's changing up 5 times so would have to have 6 gears (I think) due to road speed starting at 70ks. I think the first two bumps before 75ks would be gear changes. Clutch slippage maybe?