Trying to rebuild 2007 engine with reliability of stock engine?

[Alstrup]

Hello. the above comments about a tricky or bad combo is correct. As Glen states, there is a severe mismatch between the intake and exhaust side. heads like that are best suited for high rpm, - or turbo engines.
You state that you rarely rev past 3000 rpm (!) Then why on Earth did you get/build an engine with cam and heads that has its primary work area in the 3000 - 6500 rpm range??? - Well, my guess is that you got carried away, or the salesman gave you a good speach on whatever parts he had on the shelf. We´ve heard that one before. There is nothing wrong with the parts when we look at them isolated. When we look at it as a combo that changes.

OK. Back to the options. My question would be: What do you REALLY want?
You menthion stock like service. do you mean dropping duals and go single carburettor?
Reality check: Are you REALLY driving it like an old flathead V8? If that is the factual case, I suggest you think in lanes that will make the VW motor pull like a flat head V8 (with less numbers of course)
Are you ready to switch at least cam, heads, carbs and exhaust to get what you want?

Be specific. Then I/we can set you up with almost exactly the type of engine you like.

T

[brownnugen]

[Alstrup]

A flat head V8 is super lazy and forgiving, and wohnt rev much past 4000 rpm in stok form at least

We can set you up with a (modified) stock carbed 2007 that will pull from just over idle to about 5000 rpm and end of story. It will peak with about 100 - 105 hp at about 4300 and have lots of usable torque from about 1300 rpm. But you will have to loose at least the heads and cam. I can work my way around the exhaust if you really want to keep it.
- MAYBE - I could work my way around the heads too, but that would require that I know exactly how they behave (flow) port volumes etc. But i doubt it will be worth the effort.

This is a 1914 std plus that I built back in 2009 or 2010 I forget. Today`s version pulls the same hp but about 10 Nm better torque, and is actually cheaper to build.
This particular car is a ´69 with a 3,88 R/P transmission and 195/65 x 15 rears. It does 30 to 130 km/h in third gear in 28 seconds. Now that´s usable torque. i think it is something like this that you really want at the end of the day.
https://www.thesamba.com/vw/gallery/pix/1122049.jpg

[mark tucker]

are you sure about all the parts in the motor? as in the heads scat has a few diferent style heads. think the combo can be made to work, but......like I said I havent seen it and dont know that cam. with that said if you just want a 3000 rpm motor with lotsa power...build a big mild motor with about 9:1 cr. get it all skettered and see whats what...or sell it as it is and start over the right way.

[modok]

He's "WILLING" to ditch the dual carbs.
That's an odd statement. Usually that means the VW enthusiast is heading for ruin........but, not sure if that's the case here.

I think if you want to run a stock carb....do it! Sure, but you have to follow what Alstrup says. There are a lot of things that will work if done right, and won't work if done wrong, it's true of everything, old, new, dual, single, and so on.

[brownnugen]

Glenn, by saying that I am willing to ditch the dual carbs, I meant that if I can get my engine (whatever it turns out to be) to drive reliably and be less complicated with a single carb, then I would seriously consider swapping from dual to single carb. Even if there is a compromise on top end performance, I would consider it, as long as I can drive it safely at highway speeds and get decent mileage.

[PumaVW79]

[mark tucker]

Ive never run a single bbl carb on any thikng but my dirtbike's and my 4 wheeler and a 45 year old 2cyl Johnson (boat motor). duel idf's are the way to go.or duel 4bbls. I have many of those too.somuch eayzer and faster too.

[vugbug68]

It sounds like that engine was not built very well, sure the combo is a bit weird but it still should have been fun to drive. I've daily driven performance VW engines for years and I would drive my bug anywhere. Do your homework and rebuild the 2007cc, that is far from a radical race engine that needs constant attention.

78x90.5
5.5 rods, B pistons
engle 120 cam or similar
mild 40x35 ported heads, (the ones you have will probably work)
keep the 40 IDF's with 32-34 venturis
1.5" merged exhaust
9:1 compression
_________________
71 Super - Backroad Thrasher
66 Corvair - Weekend Cruiser
90 4 Runner - Muddin

[brownnugen]

Sorry for the delayed response/update as I was traveling.

I finally was able to bring my engine to my friend's house to try to figure out what could be wrong. The heads and cylinder checked out fine, except it looks like I was running rich. This may had been from when I used to have dual 44 IDFs that were probably not correctly jetted. I now have dual 40 IDFs that John jetted for the specs of this engine so I am thinking that should be ok.

One obvious thing we noticed was that I had 5/16 stock size pushrods instead the 3/8" cut to fit pushrods that I had ordered and listed on the build sheet. My friend was saying that I needed pushrods longer than stock size in order to get the valve train set up correctly. I think that could help explain why my engine was running so bad and hard to tune correctly. So I was planning to order some new pushrods; does the 3/8" ones in the 11.60 size as well as an adjustable pushrod measuring tool sound correct? I am still learning about valve train geometry.

I am glad we decided to the engine partially apart to diagnose this; I don't know how else anyone would have noticed it.

[Alstrup]

Stock length push rods sounds about right for such an engine, (Somewhat dependant of rod length) But stock ones are not strong enough for dual springs, so yes they need to be replaced.
If you want to try and fix the engine "as is" you should locate a set of pre 69 1200 rockers. (They are only 1-1 ratio) install these on the exhaust side alone. That will bring the I/E ratio down a bit and will make the engine much more tuneable.

T

[mark tucker]

pushrods usualy do not have anything to do with tuning. and the length is determined by setting the valve train geo. so.. you get the adjustable pushrod then determan the pushrod length and make the new ones that long.

[Howard 111]

I would change the cam, heads, and header size, and tune the carbs accordingly. And fix the compression reading differences. That lowest one has a problem somewhere. 8:1 CR.
_________________
1973 Karmann Ghia
Turbocharged, Fuel Injected
http://www.thesamba.com/vw/forum/viewtopic.php?t=531270

[nsracing]

The engine is at my garage-we already tore it down and the parts look okay. One or two lifters were chewed. Cam was good. Deck height was around 0.120" ... not including the head step another 0.035"

We trimmed the bottom of barels to tighten the deck to make this more crispy. I will take the bottom end apart and check the balance- why not my balancer is not doing anything right now.

He plans to post the build up. Maybe pics and vids- like that one balance work we did last time w/ Astroman's crankshaft.

So i will back off from reloading ammo to a VW engine next 2 weeks. Wish us luck.

[brownnugen]

Update:

here is what my engine bay looked like for the past 12 years. As stated earlier, the engine never idled well, was not responsive to the throttle and only got 10 mpg. No matter what VW shop I brought it to, they were not able to fix my issues. I knew I couldn't continue keep paying someone to try to fix it, only for it not to be truly fixed.

My first big decision was whether to just get rid of everything and go back to a stock motor (just for simplicity's sake) or fix what I have. After looking at my old list of parts and how much I had already invested in the old engine, I decided that I should at least take it apart to see if there was something obviously wrong with it. I had nothing to lose but some time.

I had never pulled an engine before, so I was really intimidated by having to remove the dual carbs, linkage and manifolds. After seeing how easy it was to get the carbs off, I figured that I might actually pull this off. I won't bore you with the details but the only collateral damage from the engine pull was I cracked my distributor cap.

I don't have a garage or a decent indoor work space so I brought my longblock down to some of my local VW friends. We wanted to see if there was anything obviously wrong with the engine. After helping me take off the header and heads, we couldn't see anything that was wrong, but noticed that I had an excessive amount of deck height (about .1") just from the top of the pistons to the top of the cylinders. One of my friends recommended just putting it back together as I may just have a tuning issue. I initially agreed and started to put it back together. All this time, I had been communicating with Alstrup and he provided me with a lot of great advice, one being that if I left my deck height as is, my car would continue to get crappy mileage and be difficult to tune. So, I was convince to at least fix my deck height problem.

Since I live in Northern Virginia, I was looking around for a local machine shop that could trim my cylinders so I would have a deck height between .04" and .06." After calling around so the local shops only to learned that they didn't want to work on my car, I remembered meeting and chatting with nsracing (Nick) about 5 or 6 years ago and asked if he would be able to help me out. Well, I am glad that he agreed to help me because if I had just brought my parts to a random machine shop and told the what I thought I wanted done (trim about 1 mm from the top of cylinders), it would have been all wrong and I would have wasted my money and trashed my parts. I wasn't planning on splitting my case either (because I had never done that before either and was not sure what I would find) but Nick convinced me to do so since I had already broke it down to the short block. I am glad I did because we found one damaged lifter. That one decision to split the case and discover the damaged lifter probably saved me from a lot of damaged parts down the road.

Nick showed me a lot of things on my engine that were either done wrong and/or sloppily put together; had I tried to put everything back together by myself, I think I would have done the same sloppy things or made some other rookie mistake that would have ruined my parts or made it run bad. So, at this time, I made an executive decision to work with Nick so I could actually learn what it takes to put together a stroker motor and make sure it was done correctly.

My priorities for this engine is reliability, driveability (from idle up to about 4-5K rpms), durability, and good mpg. Being a pretty tight budget, I wanted to rebuild this thing using as many of the existing parts that I had. If there are some things that need to be changed, I would do it.

Stay tuned for updates as I can capture them.

[brownnugen]

So, what I thought was a deck height of 0.1" actually turned out to be 0.120" ... not including the head step another 0.035"

Nick trimmed the cylinders so there would be a deck height of 0.045" as well as machined the heads to take out the step.

Since Nick had all of the equipment and knowledge to balance the engine, we decided if we are going to take the time to rebuild the engine, we might as well make it as durable and precise as possible. So after cleaning up all the parts, we weighed the pistons and connecting rods to establish a baseline to figure out how much weight would need to be removed.

As you can see, the pistons varied by 2 grams, 6 grams and 9 grams.

I am not sure how I was sold a set with this much of a discrepancy. The connecting rods were actually balanced within a 1/2 grams so we didn't need to do any work there. Here is Nick taking some weight off of a piston:

[brownnugen]

Here are a few pictures of the pistons after getting balanced.

The lightened (and previously balanced) flywheel and Berg Equalizer pulley were mounted on the balancing machine to check how balanced it was previously.
With everything rotating on the machine, it was apparent that the flywheel was about 12 grams heavy on one side. The pulley was also off.
Here is the balancing machine with just the crank on it.

Here is the machine with crank, pulley and flywheel mounted

Here is how much it was off on the left and right side

Because the flywheel was previously "balanced", you can see it drilled in several places. In order not to weaken areas of the flywheel, instead of taking weight off the heavy side, some metal was added to the lighter side.

This was the same for the pulley as well:

If I could figure out how to post a video, I can show you the final balancing.

[nsracing]

The pistons were heavy 2 grams, 6 grams, 9 grams. - balanced to 1/10th gram.

Ghe crank by itself was not too bad. The flywheel was drilled all over the place some drilling even went through. Not sure why it will take that many drillings to make unbalance corrections. But there were a lot of drillings. I welded the light side instead of putting anymore holes in the damn thing. Final spin of whole assemnly was around 0.34 oz inches.

Will update as we go on this build.

He got to grind the valves on the Sioux grinder. 😀😀

[Howard 111]

Something I've always wondered. Why doesn't everyone use the lightened wristpins? Those heavy stock pins were VW'S over-engineering everything. The lightweight pins are just the stock pins drilled out to take off lots of weight in a spot removing weight has a good effect.

I've run them in every motor I've built since I knew they existed.
_________________
1973 Karmann Ghia
Turbocharged, Fuel Injected
http://www.thesamba.com/vw/forum/viewtopic.php?t=531270

[modok]

Stock wrist pins are very thin-wall my modern standards.

The big bore ones are a little thicker, but not excessive. The light pins are almost as light as stock , and you can use them in most things as longas theres no turbos involved. The best way to make them lighter is use a slipper skirt piston that uses a shorter pin.

Good job fixing most of the problems! What as the CR before?

Are you going to get the 40 horse rockers to dial back the exhaust? Costs almost nothing, so do it.