I've been reading about engine modifications and upgrades. And I got a question about the 1641. Is it true that the thin cylinder walls of the 1641cc cause it to overheat and give all sorts of problems?
As for the 1776cc - is it suppose to be a better improvement over the 1641cc due to the fact that the crank case is bored out to make way for good sized cylinders?:beer
But still if the crank case is bored out - wouldn't that weaken it?
And so which is better? The 1776 or 1641cc? ie in terms of durability and reliability and heat tolerance?
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Owner of a 1964 VW Beetle, 1641cc engine, etc..
Hi there I have a 1641 in my Type 3 Square and I have no problems with it overheating. That all said and done thought this engine came with the car and as their is nothing rong with it its staying in there. But if i was to build a new motor for it Id build the biges one I could practically afford. Thes day you'd only realy start to have problems of weekness when you start using large bores & stroke combinations. Go the 1776 and make shore you use a balanced crank and youll be right.
Nige :thumb
BizarreModeratorThe artist formerly known as blue74l
Once again you are going to get every different opinion.
Here are mine
1641 - are 87's and are thinner than 85.5. That said they are better than slip in 88's
I wouldnt bother with 87's cause by JUST doing the Pand C change you aing going to notice much different.
When you go 90.5 you HAVE to split the case and for the little money required you can throw a nice can in and balance the crank. Probabally get a counterweighted one.
If you are doing that you may as well get 94's
The difference between 1585 and 1914 is 20% and cubes DO make a difference
But the difference between 1641 and 1585 is 3.5% - Stuff all
If you did a 1776 and ONLY changed P&C's i doubt you would notice much of a difference. It is all the other stuff - carbs cam compression ratio, light fly wheel, valves, head porting, matched manifolds etc etc
Overheating - it HAS to. It is thinner. How much is another question. A 1641 in a light bug in Tasmania is not as much of a problem as a 1641 in a 1973 Kombi in Darwin that regularly drives to Katherine with 9 people, 4 dogs, towing a trailor and a load of fire wood.
Personally i would build a hot 1585 and get the safety of the extra mm's in the walls.
One of the favourites of the old skool was machine in 88's. This gave 1679 but were thick as. A big favourite with busses
I should have added that I already installed the engine into the Beetle - a 1965 ex-1200cc model.
My mechanic in Thomastown - highly respected in the Melbourne circles - fitted it in for me.
The engine was also balanced, and we installed in quality parts like a Mahle 87.5mm PnC, Engle 110 camshaft, heavy duty springs etc..
All up the engine cost me about $3700. (I also put in a stronger transmission but that's another story.
The reason why I went for a 1641cc is because - hey I don't have any major mechanical experience - and I trust my mechanic. He's a good bloke and has helped me out in the past. I went to AVWPC and Volkspower before in the past but... anyhow that is another story.
:alien
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Owner of a 1964 VW Beetle, 1641cc engine, etc..
"But nonetheless if we do machine the case and increase the power to a 1776 or 1916 etc.. won't the engine heat increase exponiently too? "
Yes - ish. What the problem with the thinner (87, 88 slip in and 92's) is that the heat created warps the barrels and causes blow by. Rings dont seal properly. Stock cooling should be able to cope with the heat. It is how the steel copes with the heat
"And surely machined out the crank case to make way for the larger PnC will weaken the case, won't it? "
Not really but depends. This is where talk of case savers and 8 vs 10mm studs and dual pressure relief and decking comes in
94mm is the largest in stock cases.
Futue te ipsum!!!
Craig Torrens6 times Australian, 7 times State Hillclimb Class Champion
mate you did the right thing to go a 1641. they are a good strong motor for the money. my thumper has been thru hell and back but is still there.
but i gotta say i just got a 1776 twin kad and it has blown me away. this next step up was a biggin, and i am so happy i did. and im sure hte 1916 and so on is even better. but they would ev been too hot from all i spoke to for my bus. if you want to play safe go 1776. power for work is good. if wan t abit more and am very concious of what your motor is doing then the sky and wallet is hte limit.
would suggest that you have a pressure, temp guage set up, if you havent already.
twoguns wrote:would suggest that you have a pressure, temp guage set up, if you havent already.
I talked with many people over the internet over the merits of the 1641cc and 1776cc++ and 90% of them say that the way to go is to bore out the crank case to make way for bigger cylinders etc... But when I talk to the VW mechanics here - they support the 1641cc.
Anyhow its been interesting hearing the discussions.
But placing an oil temperature gauge would be great. Is there a DYI kit available?
I will be getting the hoodjacks to place into my Beetle lid in about two months time.
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Owner of a 1964 VW Beetle, 1641cc engine, etc..
Time =Money,maybe theres more profit in a quick build 1641 than a longer build time 1776,but hey i dont know,if yuv got a 1641 and its built right enjoy it,theres a million of them out there and there not all self destructing handgrenades.😉
