All motor 8v.

[4RingsRuleALL]

Ok, I've been reading and reading, here goes.

1.8 RV block

ABA X-Flow head with extensive P&P done by me on my own flowbench.

312degree or possibly higher Camshaft depending on price from TT.

Stronger Valvesprings

CV carbs from a motorcycle.

Custom intake manifold made by me.

4-2-1 factory 8v manifold with TT race downpipe.

MSD-6AL Ignition.

What Im going for here is a mix of high revving power and relatively low cost. Im shooting for 130+WHP and thats conservative. Ive seen a similar combo on a rally car making 160whp and one with a counterflow head making 178whp. Im a machinist, so I have access to the right tools for the job and have some talented welders as friends. Whats everyone's constructive opinion on this setup? It will be mated to a 4K O2O trans so I will be utilizing my high rev range. Wont be daily driven.

Itd be nice to build an 8v that can strike fear in the hearts of chipped 1.8t mk4 kids.

[B4S]

All that work...and a factory dual downpipe? I'd go with one of the higher-end 8v headers, like from techtonics.

[superl8]

why not use the 2L bottom end as well? I had a 2L ABA with a counterflow head using a tri-y header - It cracked (my fault due to wrap and moisture) so I switched to the dual outlet with the TT race downpipe. By my reckoning it lost a bit o jam. The header was a craigslist find with smaller primary and secondary tubing than the TT. Just my experience.

I also took nearly the entire bell off the flywheel into a close ratio tranny - a 280 deg duration cam and port and polish.

Usual 8v stuff. Obviously still not a powerhouse but it was ridiculous fun to drive. Constantly spinning wheels. Felt and sounded the biz

Whatever you do I'm sure you'll have a blast.

[4RingsRuleALL]

Ok, fair enough, If I'm going through that much time and effort I may as well have a proper escape route for the exhaust.

The reason I do not want a ABA block is because in my experience, the 1.8 motors like to rev more than the 2.0 Maybe its less rotating mass, maybe is the bore vs stroke. Unless all my previous engine building knowledge is completely useless in the VW world, Short stroke and big bore is going to generally make more power up top at the cost of low end TQ.


BUT thats ok. I want this to rev. Im kinda thinking about going ITB but then Id be kind of getting away from my goal of low budget.

I also want to keep the RV block because its in there now and then I wont have to worry about block height.

[ps2375]

The ABA has a good rod length/stroke ratio as does the RV. It gets worse on the 2L motors w/ 144mm rods.

To make any of them rev nicely, a balancing of the rotating mass (including the FW & PP) and turning of the IM shaft are a must.

[4RingsRuleALL]

The ABA has a good rod length/stroke ratio as does the RV. It gets worse on the 2L motors w/ 144mm rods.

To make any of them rev nicely, a balancing of the rotating mass (including the FW & PP) and turning of the IM shaft are a must.

Have any links on the IM shaft turning?

I guess I need to price out some of the finer stuff. Its going to be a raw motor unless I drop some coin, the point of the build is to build a relatively inexpensive 8v that can run with hopped up 16vs and stock vr6s .

I know I could a decent amount more power if I went with ITBs, bigger vales, High CR pistons, etc. I may as well just start a 20v NA build.

I want to pp the crap out of it, throw a big cam on, bike carbs then spend my time tuning it on a dyno.

[ps2375]

The RV head has the larger stock valves, so unless you spring for oversize valve, those will do. As for turning the IM shaft, just put it on a lathe and turn the section between the bearing surfaces until it is straight (it already has the centers drilled in the ends). Just be sure to radius the inside corners. And the stock pieces, balanced, should be good for decent NA power.

[ziddey]

ABA IM shafts

If you're really not thinking about going ABA, you'll find a lobe on your IM shaft that I believe is a vestigial feature from the days of carb mechanical pumps? Or maybe diesel?

[4RingsRuleALL]

Nice! Thank you. Got a rough number on the OD? I'm assuming that this mod is based on the idea of less rotating mass.

[ps2375]

More based on the fact that they are not straight and will reduce vibrations. Stick one between centers and rotate it, you'll see exactly what the mod is based upon.

[ny_fam]

How is this build going?

Whats the value of the MSD-6AL Ignition? Vs stock distributor ignition?

[4RingsRuleALL]

Started collecting parts then I was laid off due to lack of work in my area. So unemployment doesnt pay enough for my toys lol suppose Ill just slowly keep gathering parts.

[Glegor]

Ok, fair enough, If I'm going through that much time and effort I may as well have a proper escape route for the exhaust.

The reason I do not want a ABA block is because in my experience, the 1.8 motors like to rev more than the 2.0 Maybe its less rotating mass, maybe is the bore vs stroke. Unless all my previous engine building knowledge is completely useless in the VW world, Short stroke and big bore is going to generally make more power up top at the cost of low end TQ.


BUT thats ok. I want this to rev. Im kinda thinking about going ITB but then Id be kind of getting away from my goal of low budget.

I also want to keep the RV block because its in there now and then I wont have to worry about block height.

why do you have to worry about block height? even with the stock intake manifold, and full crossflow head, the ABA fits in mk1, and mk2 cars NO PROBLEMS..

the ABA is capable of basically the same revs as the 1.8.. ive heard that either bottom end is good till 7500 or soo revs.. the valve train is going to be the limiting factor i feel..

and based on that, i would use the 2.0L engine, just because its bigger, and will make more power with the same mods as a 1.8L engine..