Cheap performance engine

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Graupe1
Posts: 5
Joined: Wed Jun 26, 2024 12:00 pm

Cheap performance engine

Post by Graupe1 »

hello i wantet to build an cheap performance engine so i went and bought some performance parts but realized i probably should have started with a plan i kinda dont know what compression ratio i should go with, and if the original vw heads even have enough flow so i am going to list the parts i have and i hope someone can tell me if that engine is even going to run this is my first performance engine build so i defenitly went to fast with too little planning i wantet to keep

camshaft slr xr310 (06 206)
other camshaft weber 294°
lightweight lifters
rocker arm 1:1.25 (i think not sure how to determine this)
92mm piston aa performance
pushrods chrome moley
double valve springs

crankshaft currently stock (i search for an counterweight if i dont find a cheap one i am going to balance this one)
heads are original dual port orignal valve (thought i might port them and cut some bigger valves)
gasoline i want to use super 95 roz witch should be moz 85
I know I probably sound stupid because I'm new to this hobby, but I have to start somewhere.

thanks alot for your help and time
Bruce.m
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Joined: Sun Aug 11, 2013 1:44 pm

Re: Cheap performance engine

Post by Bruce.m »

Stock crankshaft is max 5k. It bends above that and beats the crankcase. So no point using a camshaft that moves the rpm range beyond that.

Stock heads can be ported to some extent but the valve size is the ultimate limit. Replacement Autolina heads, actually have a better port shape especially the exhaust but still benefit from light port work & a good 3 angle valve job.

What crankcase do you have? If an old period case, what state is the bores because it’s highly likely to need machining unless it’s had low miles use & a couple of decades sitting in a shed.
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oprn
Posts: 214
Joined: Sun Apr 09, 2017 8:21 pm

Re: Cheap performance engine

Post by oprn »

The cheapest performance engine possible is a bone stock, all original German parts 1600 SP or DP with a properly sized turbo (crossover 2300 - 2500 RPM) limited to 8 psi boost and 5000 RPM. A draw through carb simplifies the fuel delivery issues, a few degrees spark retard under boost and Bob's your Uncle!

It will not make huge dyno numbers but you will be running with the N/A guys that have spent 3 to 4 times the money and if you can weld a few exhaust pipes together the whole thing can be done pretty darn reasonably. I did my boosted 1600 for the cost of the turbo, a few "U" bends, a used side draught carb and lots of tinker time. It had enough torque to smoke the stock clutch on a hard shift.

Or you can take it up a few notches like Clonebug did and clean house on all comers except the top 3% that have unlimited toy car funds.
Bruce.m
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Joined: Sun Aug 11, 2013 1:44 pm

Re: Cheap performance engine

Post by Bruce.m »

All very true :)
Graupe1
Posts: 5
Joined: Wed Jun 26, 2024 12:00 pm

Re: Cheap performance engine

Post by Graupe1 »

@bruce.m
Can I cut in some larger valves in the stock heads of the AS21 engine case that I want to use? I also have an AS41, but I've heard that the 21 is superior. I'm stuck looking for used heads because there aren't really any for sale where I live. Crankshafts occasionally turn up, but heads never do.
Graupe1
Posts: 5
Joined: Wed Jun 26, 2024 12:00 pm

Re: Cheap performance engine

Post by Graupe1 »

oprn wrote: Thu Jun 27, 2024 4:33 am The cheapest performance engine possible is a bone stock, all original German parts 1600 SP or DP with a properly sized turbo (crossover 2300 - 2500 RPM) limited to 8 psi boost and 5000 RPM. A draw through carb simplifies the fuel delivery issues, a few degrees spark retard under boost and Bob's your Uncle!

It will not make huge dyno numbers but you will be running with the N/A guys that have spent 3 to 4 times the money and if you can weld a few exhaust pipes together the whole thing can be done pretty darn reasonably. I did my boosted 1600 for the cost of the turbo, a few "U" bends, a used side draught carb and lots of tinker time. It had enough torque to smoke the stock clutch on a hard shift.

Or you can take it up a few notches like Clonebug did and clean house on all comers except the top 3% that have unlimited toy car funds.
that sounds very fun but i live in germany a turbo will not be legal in any way would like to do this tho sounds verys fun
Bruce.m
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Joined: Sun Aug 11, 2013 1:44 pm

Re: Cheap performance engine

Post by Bruce.m »

There are a few Europeans on here from time to time. Hopefully they can advise on TUV approval options.

I’d suggest plenty of background reading on your options. Also worth watching the Jugan Linse videos on YouTube (you won’t need the subtitles!) as they are very in depth on a 1600 build & also a strong 1800 build.

One point. You mention dual valve springs, which are only really needed for high rpm & big (heavy) valves. There is little point in using them with a stock crankshaft because you can’t get the rpm high enough to make those necessary.

Choosing a well matched set of parts is important to get good performance, reliability & value-for-money.

I built a mild 1641cc engine that cost me very little. As an example. I had a core engine that had sat unused for 20 years, so although it was worn & needed a full rebuild the crankcase was within spec. I was gifted some autolina heads which I hand ported / 3 angle valve job. I bought the pistons / barrels & full set of bearings. I used stock camshaft, stock new lifters, shortened stock pushrods, stock crankshaft, stock flywheel. With custom motorbike throttle bodies, forged 1.4:1 high lift rockers (ordered direct from the USA) & old used stainless sport exhaust. This makes about 83bhp which is fine for the cheap cost.
Graupe1
Posts: 5
Joined: Wed Jun 26, 2024 12:00 pm

Re: Cheap performance engine

Post by Graupe1 »

Bruce.m wrote: Thu Jun 27, 2024 9:26 am There are a few Europeans on here from time to time. Hopefully they can advise on TUV approval options.

I’d suggest plenty of background reading on your options. Also worth watching the Jugan Linse videos on YouTube (you won’t need the subtitles!) as they are very in depth on a 1600 build & also a strong 1800 build.

One point. You mention dual valve springs, which are only really needed for high rpm & big (heavy) valves. There is little point in using them with a stock crankshaft because you can’t get the rpm high enough to make those necessary.

Choosing a well matched set of parts is important to get good performance, reliability & value-for-money.

I built a mild 1641cc engine that cost me very little. As an example. I had a core engine that had sat unused for 20 years, so although it was worn & needed a full rebuild the crankcase was within spec. I was gifted some autolina heads which I hand ported / 3 angle valve job. I bought the pistons / barrels & full set of bearings. I used stock camshaft, stock new lifters, shortened stock pushrods, stock crankshaft, stock flywheel. With custom motorbike throttle bodies, forged 1.4:1 high lift rockers (ordered direct from the USA) & old used stainless sport exhaust. This makes about 83bhp which is fine for the cheap cost.
Yes, Jürgen Linse is fantastic. I asked him once in a forum, and he attempted to assist, but he became impatient with me and my lack of experience.
do you guys over sea sell some used parts i could buy ? i am currently 300€ into this and an crankshaft would double that heads would tripple that
Graupe1
Posts: 5
Joined: Wed Jun 26, 2024 12:00 pm

Re: Cheap performance engine

Post by Graupe1 »

Bruce.m wrote: Thu Jun 27, 2024 9:26 am There are a few Europeans on here from time to time. Hopefully they can advise on TUV approval options.

I’d suggest plenty of background reading on your options. Also worth watching the Jugan Linse videos on YouTube (you won’t need the subtitles!) as they are very in depth on a 1600 build & also a strong 1800 build.

One point. You mention dual valve springs, which are only really needed for high rpm & big (heavy) valves. There is little point in using them with a stock crankshaft because you can’t get the rpm high enough to make those necessary.

Choosing a well matched set of parts is important to get good performance, reliability & value-for-money.

I built a mild 1641cc engine that cost me very little. As an example. I had a core engine that had sat unused for 20 years, so although it was worn & needed a full rebuild the crankcase was within spec. I was gifted some autolina heads which I hand ported / 3 angle valve job. I bought the pistons / barrels & full set of bearings. I used stock camshaft, stock new lifters, shortened stock pushrods, stock crankshaft, stock flywheel. With custom motorbike throttle bodies, forged 1.4:1 high lift rockers (ordered direct from the USA) & old used stainless sport exhaust. This makes about 83bhp which is fine for the cheap cost.
but you saw the parts that i have what parts should i buy to complete this engine ?
Bruce.m
Posts: 913
Joined: Sun Aug 11, 2013 1:44 pm

Re: Cheap performance engine

Post by Bruce.m »

Decide on your crankshaft.

If it’s stock, sell the camshafts, springs, pushrods & possibly the lifters because they aren’t a good match to a 5k max rpm.

Jurgan has figured out engine specs that work together. Enough to know what carb jets to fit without tuning because he knows them well. The idea of putting together a mismatched set of unknown parts makes no sense to him because his engines need to work well & not break down.
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BugUgly
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Re: Cheap performance engine

Post by BugUgly »

Bruce.m, thanks for the tip about Jürgen Linse. I wasn't aware of him, and it will combine my goofing around, watching car vids on youtube, with something good for my brain...improving my 30-years-stale high-school Deutsche.
Bruce.m
Posts: 913
Joined: Sun Aug 11, 2013 1:44 pm

Re: Cheap performance engine

Post by Bruce.m »

Yes. Interesting watch. Another guy published the block of videos rebuilding a 1600 & an 1800 stroker.

One snippet. He cuts a grove in the case half sealing face (!) from the area where the flywheel shims live across to the inside of the case. This is to drain that area. VW drilled the drain hole so a puddle of oil remains there keeping the shims wet. However the VW puddle is above the real main seal lip. Modern synth oils can creep past the rear main seal very slowly over a winter rest period until the puddle drains below the seal lip. He doesn’t like an risk of leaks
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