Bastard 1641

[RUSS74GHIA]

I'm planning a spare race engine. For reasons i won't in into it's going to be 1641cc. It's going to be n/a and used for drag racing only. I've a few thoughts on spec, but wondered if anyone had any thoughts. Also, max valve sizes anyone?

[autohausdolby]

What's the maximum compression ratio anybody has run on a factory head casting engine?

[autohausdolby]

Or has run successfully for a small number of passes anyway 

[BeetleBug]

Or has run successfully for a small number of passes anyway 

What about 11`s from a 1600cc engine? Enjoy: http://cal-look.no/lounge/index.php/topic,3257.0.html

[jamiep_jamiep]

I remember seeing Microgiant running very quick numbers with a 1600 or a 1641 many years ago Russ, I know it had IDA's, but at the time I was into 'britlook' so didn't pay much attention.... maybe do a search for the spec on that car?

If it had spatter paint on the engine I may have paid more attention 

[Neil Davies]

I ran a 1584 into the 15.7's in VWDRC in the early to mid 2000's. I've posted on here a few times about it - basically a stock longblock with mildly ported heads, 1.25 rockers, 36DRLAs, 1 5/8" merged header, lightened flywheel biut nothing really that special. I used a Cogbox close-ratio gearbox (can't remember the ratios off hand but it was a 1.31 fourth gear and a 3.88 R&P - all four gears were non-stock ratios) with race axles and Ercos with 6" Phoenix slicks. Basically the same set up as for my low 12-second 2276! I'd launch at about 5000rpm and shift at 6k - I know that 4k is supposed to be the limit on a stock crank, but it was a short term motor! The car was weighed at 1639lbs ready to race with me in it.
Incidentally, that motor now sits in my street car with full cooling and a pair of 40DRLAs (the 36's siezed after the car was sat for 3 years with standoffs on the engine lid...)

For a budget 1641, go for nothing too wild. You're limited on valve sizes by the size of the cylinder, but you should look at getting fuel and air in and exhaust gasses out as efficiently as possible - I tried IDAs on it once but they were a bit much for it (flat spots and stumbles), although I didn't do much to the jetting and did leave the 40mm vents in them! What I did notice was that the engine revved higher so you could look into big carbs - maybe the same ones as your big engine but with a different set of jets/vents?

[RUSS74GHIA]

Thanks guys.

I'm thinking properly match-weighted & balanced bottom end, nothing too mad on the cam, but high CR. I think high RPM is the key and a silly cam will hurt lower down.

So what about W-110 cam with 1.25:1 , but say stock valves, 12:1CR with 40DRLA, 30vents?

[Zach Gomulka]

Once again... 

1600cc, 40x35.5 044's, 8.5:1, 110x1.25, 1 1/2" merge 44's w/ 36 vents ran a 14.87 @ 88mph in my light daily driver 67. 4.12 box with 1.48, 1.04. I think I could have cut a few tenths off with more seat time.

[volkskris]

http://www.keversite.nl/motoren/motor.php?id=58
sorry that it's in dutch, little translation here:
p&c's: mahle 87 mm
crankshaft: CB counterweight
rods: CB H-beam
Camshaft: W120. GB pushrods & lifters
heads: los banditos (ported)
comp: 9.5

[RUSS74GHIA]

Thanks for your input chaps.

[benssp]

I remember seeing Microgiant running very quick numbers with a 1600 or a 1641 many years ago Russ, I know it had IDA's, but at the time I was into 'britlook' so didn't pay much attention.... maybe do a search for the spec on that car?

If it had spatter paint on the engine I may have paid more attention 

Tonys motor was a 1600 with 48idfs, stock crank!! and big valves( it runs 90.5 barrels with a sleeve with reliefs to clear the valves, dry sump etc,10k plus revs. ran 13.01 in the prince of darkness, he's rebuilding the motor and said I can borrow it as long as I pump up the tyres, change every fuel & hydraulic line in the car....oh and store it as the barn it's in is falling down