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Engine questions (sorry for the long post)

Hi RAMVA! It's been a while since my last post, and I've been buiding my new engine, so questions about it have been acumulating.

I put in the spare engine 1300SP into the bug and dissasembled the old engine for inspection. I already contacted a machine shop (not familiar with VW's, so I have to tell them exactly what do I want to be done) to do the work and decided to check every part from the old engine, even the parts I'm not reusing.

The connecting rods look in good condition, but the rod bearings are all yellow and worn. Since I will be balancing the new rods once I get them, I set up the balance (ohaus triple beam 0.1 gram accuracy) and practiced with the old ones. There's a difference of 15.6, 10.8 and 0.8 grams beetween the heavier ones and the lightest. Maybe the PO replaced one or more (# 3 is the heaviest). I know the PO had the engine overhauled about 2 years (and 7,000 miles) ago. And replaced the block with a (new?) mexican AS41. Do you think the unbalanced rods may have caused any considerable wear on the case? I don't have any means to measure the out of roundness, but the main bearings seem to fit well and tight.

When he rebuilt the engine, he used the old camshaft (it is worn), and lifters (all worn). Don't know about the cam bearings but they are worn also. I already bought new cam bearings and they fit right (Again, I just tried them by hand and they seem to fit well). I also found a Norris 402S cam that was used just for 30 minutes on a test stand. It looks new and I'd like to use it. What lifters can I get for it? can I use hydraulic lifters? what kind of machine work needs to be done to accomplish that?

The crank looks in good condition, maybe he replaced it then. It is a stock 69mm, but I'm not using it, I'll just store it just in case I need one in the future.

I removed every part of the case and cleaned everything up really well (lots of silicone gasket maker there). Managed to get the oil pressure relief bolts, springs and plugers out. Now I'm wondering? how do I check if the springs have the proper size and tension?

Right now this engine rebuild is been really fun, I'm learning a lot. I'll try to post pictures of the process in a few days. Please feel free to post your opinions on all these questions. If the case is unusable or it needs to be align bored, I also have a brazilian AS21 that can be used. Is this case good for a stroker engine? I know it is a different alloy, but that's about all I know. Which one is better?

TIA, Karls

Reply to
Karls
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Major alarm bells are going off. First off, a machine shop that is not familiar with aircooled cases is a bad gamble. I would scour any local VW sources to find out where they farm out their work.

Both cases could be fine or junk regardless of the mileage. Strip them down, bolt them together with the 6 large nuts, torque them to spec in the proper sequence. Hold them up to the light and see if you can see any sliver of light where the center webs connect just above and below where the bearing would be. Any light = scrap heap. Any globs of silicone rubber inside the case = idiot. If you find the case to pass this test, consider getting a plug kit, pull the factory plugs, and clean up the passages. There are lots of posts on various forums describing this procedure and considering what you've told us, I would consider this a neccessity. If you are unsure as to the shape and proper relief springs, Berg sells a kit that has everything for when people buy new cases. Wasn't that much if I recall and it was a genuine VW kit.

Rods are way out. Look for a rebushed set from a reputable supplier. That means Aircooled.net, Berg, etc. Not one of the local pipelines to China.

The crank might make a good core or have a shop inspect it first to see what it needs. Standard or .010" under are what you want. Consider upgrading to a CW crank if you plan on high RPM.

Cam selection must be carefully considered along with what heads, carbs, exhaust, displacement, your budget, driving habits and what machine you are putting this engine into. A mild or stock engine? Stock cam is good, very good!

You can't assemble a decent engine on blind faith and enthusiasm. Mind you, many parts stores count on that to line their pockets.

RT

Reply to
Raymond T. Lowe

Thanks for your reply Raymond. Unfortunately, there are no VW-only machine shops on this island. There are some (including the one that I chose) that have worked with aircooleds in the past (years ago) but they are not "specialized" on ACVW's. So, I'll have to gamble on this. I spoke to some old VW racers to find out where do they do their work. One of them told me he tries to get the cases already bored and clearanced so he doesn't have to do all that here. Another one told me he usualy goes to the machine shop I was talking about and does the work himself (they let him use their equipment).

I did the flashlight test on both cases and they seem fine. My main concern is uneven wear around the bearings. The plugs are going to be removed anyways, since I'll bore and clearance the case for a 78mm crank. Also, a full flow oil system seems like way to go. I remember reading a post from Bob Hoover saying that I need to bore some oil passages in order to convert the case to hydraulic lifters. Isn't there another way? I know the machine shop can bore the spigot bores and clearance the case for a stroker crank. But I'd like to keep things simple for them so there's less chance to mess up things. If I have to bore the passages I'll just use non hydraulic lifters.

Rods are not going back to the engine. Is a 15.6 gram difference too much to adjust by gringing material off the rods? The new engine will have new (maybe H-Beam) rods. ACN has them for good (not great) price. But I'd like to practice and learn from the old ones. then I can save them for a spare engine.

How can I inspect the crank? Just like the rods, I'll use a new one, but I'd like to make sure this one is ok and save it for the other engine.

The cam was selected for the price (really cheep), so maybe everything else will have to be adjusted to this cam. Heads? new ones, don't know yet, probably from ACN. Carbs? Dual dellortos DRLA's (40 or 44, I can get professionally rebuilt ones for a fair price), Exhaust? Don't know yet, Displacement? 78mm x 90.5mm(2007cc, maybe 2110 if someone convinces me it will not affect the durability), budget? there's none. I know I'll spend a lot more than planed anyways. I'm not lead footed, but I like to go fast on the highway sometimes. It will go into a 70 bug. I'd like to get more power but not heat. (everyone's dream).

Thanks a lot for your help, Karls

Reply to
Karls

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