I have a Purvis Eureka Kit Car Built on a 1968 Chassis with a 1500cc motor currently being rebuilt. I'm not that experienced with Vw's & i was wondering what i could do that would make it a little bit quicker around town? I dont want to build a 1900cc+ engine or anyhting just make the 1500 a bit more powerful. Engine currently has 1-1/2" Dual exhaust, aftermarket oil cooler, air filter & thats pretty much all i know off the top of my head. So any ideas?
Ok thanks guys. The car has front disk brakes & is 780kg so a tiny bit lighter than a stock bug. everything else on the car is ready it just needs that tiny bit more go from the 43hp engine. Do you think 60-65hp from the 1500 is possible?
yeah bigger carby would be good
other wise 1600 counterwieht crank every that moves balanced
65 at the wheel with a 1500 sp would cost as much as a 1600
http://www.aircooled.net/gnrlsite/resource/articles/mods.htm
If you are currently rebuilding it seriously consider boring the case for 90.5s or 94's and putting new dual port heads to suit. Then add a mild cam.
Dont worry about a counter weighted crank - just get it all balanced
With that combo you can still run a 34Pict.
This will give you a good 40% over the stock 1500 and not cost a real lot.
Futue te ipsum!!!
BizarreModeratorThe artist formerly known as blue74l
heres some of my tuning tips that worked on my 1500sp,t3 carbs 1 inch spacer between manifold and carb same jetting each carb t3 (l and r r diffrent)12inch long pvc ram tubes(plumbing section at bunnings)recurved vacume dissy more initial less total advance,the rocker set up was a set of those old sig erson 1.4 rockers but looking back 1.4 on the intake and a set of 40 horse rockers 1.0 on exhaust(exhaust ratio makes the intake to exhaust ratio better if that makes sense)rockers set to a nice tight 4 thou intake and exhaust(adjusted really often 750-1000k`s .A nice cheap merged header(i had a 13/8in bug pack)if you want to use all of the 5400rpm potential,scat econnos would b my next choice and 3rd choice stock with no baffel tips monzas etc have no place on a vw plus they sound shit.30weight monograde oil in engine and 12 gearbox oil and 12auto transmission oil in box.good wheel alignment.And a good shifter or a quick shift kit.In my 60 beetle 3up it repeatedly ran around to over 90mph on the speedo lauchlan still laughs when i remind him.hope thats some help and rember if u see 3 purvis urekas in 1 weekday ie monday to friday u must kill your self.
Craig Torrens6 times Australian, 7 times State Hillclimb Class Champion
phantomeureka wrote:i was thinking 65 @ the flywheel not at the wheels. Might drop in 85.5mm Pistons later on for that 1585cc.
Drop in a 1640cc kit, then replace the heads with twinport heads, 8.5:1 compression, extractors, and Kadrons.................All this can be done without pulling the motor apart and you will be happy with the increase.
OK - asking cause i dont grasp what is being said here.
87s go in the same hole as 85.5
88's go in the same hole as 85.5
They must have thinner walls than 85.5??
92s go in the same hole as 90.5s
They are tinner than 90.5s
there are 94's that go in 90.5 holes but they are stepped. Different scenario.
"Slip in piston and cylinder sets are available in 'size upgrade' of 87mm and 88mm, but we do NOT recommend them EVER, PERIOD. There are NO special cases or exceptions to this recommendation. Aircooled.Net doesn't sell or support applications that use the 'size upgrade' slip in sets on 1300/1500/1600 cc engines. When slip ins are made, the cylinder walls are thinned so that the larger piston will fit"
What dont i understand??
Now - i am NOT saying 1640's are not good.
I do not have first hand experience of them warping
I do know people that are very happy with 1640's
BUT...........................
I just dont understand the comment that 1640 kits are not thin walled
Bizarre wrote:OK - asking cause i dont grasp what is being said here.
87s go in the same hole as 85.5
88's go in the same hole as 85.5
They must have thinner walls than 85.5??
92s go in the same hole as 90.5s
They are tinner than 90.5s
there are 94's that go in 90.5 holes but they are stepped. Different scenario.
"Slip in piston and cylinder sets are available in 'size upgrade' of 87mm and 88mm, but we do NOT recommend them EVER, PERIOD. There are NO special cases or exceptions to this recommendation. Aircooled.Net doesn't sell or support applications that use the 'size upgrade' slip in sets on 1300/1500/1600 cc engines. When slip ins are made, the cylinder walls are thinned so that the larger piston will fit"
What dont i understand??
Now - i am NOT saying 1640's are not good.
I do not have first hand experience of them warping
I do know people that are very happy with 1640's
BUT...........................
I just dont understand the comment that 1640 kits are not thin walled
The working area of the barrel on the 1640 kit is not thin..the part of the barrel that inserts into the case is thinner with the 1640 kits. Other larger kits (88's/92's for example) are thinner walled on the working area of the cylinder as well as where it receses into the case.The 94's require a much larger case hole to fit but the working surface thickness of the barrel is not "thin". 1640 kits are a good upgrade option for extra displacement if the old pistons and barrels require replacement or more go for little $$ is sought. I've never come across reliability issues with them....and it gets hot up here!!❗
tssnq.com.au
BizarreModeratorThe artist formerly known as blue74l
*scratching head*
if an 87 fits in the same hole as an 85.5 in the case (ie outside diameter the same)
and fits in the same hole as an 85.5 in the head (ie outside diameter the same)
yet it has an 87 piston in it
How can it not be anything other than a thinner wall??
Bizarre wrote:*scratching head*
if an 87 fits in the same hole as an 85.5 in the case (ie outside diameter the same)
and fits in the same hole as an 85.5 in the head (ie outside diameter the same)
yet it has an 87 piston in it
How can it not be anything other than a thinner wall??
I am obviously missing something 🙁
HeHe....the outside diameter of the barrel is larger than a stock barrel.The part of the barrel that goes into the case is "thinner",as is the other end.The working surface of the barrel (between the top and bottom) is thicker,just like a standard barrel.....I s'pose you could say it was stepped..😵💫
Soo.......Dual Port heads,87mm pistons, Dual Carbs, CR8.5:1 should give me a nice increase? also i have a chance to buy a "Lumpy" camshaft from a mate but not 100% if it will fit a 1500(or 1641 i guess). It was in a 1883cc previously. What hp should that bring it up to?
