1911 build from 1.7 which budget parts from AA, Hold my hand like a child Options

[nditiz1]

So I'm debating doing the top end on my 1.7 I recently dropped a valve on.

Looks like I can buy all items from AA performance. Can I just buy the 1.7/1.8 96mm P&C and the 1.8 AMC heads and call it a day? I'm getting confused on what I read about opening to 105mm bore on the 1.7 heads for 96mm Pistons. The AA website talks about modifying heads to 103mm bore. I guess I could also just use 2.0 heads, but my tin wouldn't match.

Sorry for being dumb...

[porschetub]

So I'm debating doing the top end on my 1.7 I recently dropped a valve on.

Looks like I can buy all items from AA performance. Can I just buy the 1.7/1.8 96mm P&C and the 1.8 AMC heads and call it a day? I'm getting confused on what I read about opening to 105mm bore on the 1.7 heads for 96mm Pistons. The AA website talks about modifying heads to 103mm bore. I guess I could also just use 2.0 heads, but my tin wouldn't match.

Sorry for being dumb...

IMO stick with the 96mm combo ,easy really ,cheers.

[Superhawk996]

Plan on opening the heads.

The NPR 96’s have too thin of cylinder walls and a very thin sealing surface between the top of cylinder and the heads. This was not a good combo for reliability. NLA but occasionally pop up on eBay and the like. AA performance 96 won’t have this issue.

Discussion of how much the heads are to be opened should be based on parts in hand. I wouldn’t tell a shop what to open them up to based on internet posts.

In my opinion putting 2.0L heads on just causes all sorts of drama. Either build a simple 1911 or go whole hog using the better 2.0L heads, 2.0L crank, rods, to build a 2056. Just my opinion.

My original 1.7L was my very first engine rebuild (other than lawnmowers, go karts, and cycles) back in 88’. Built to 1911, opened 1.7L heads and was reliable to the tune of 100k miles and was a nice bump in torque over the stock 1.7L.

Note: if you dropped a valve and are reusing heads - pop for larger valves if they are doing seat work anyway. Or as you say, buy 1.8L heads.

But. . . man . . . If I’m buying heads - why not buy 2.0L? . . I get it $$$. 2019 or so I sold a 2.0L core crank (regrindable) for like $45. 2.0l reman rods are pretty cheap from EMW. See where this leads (IMG:style_emoticons/default/headbang.gif) yeah, I’m probably building a 2056 if I’m buying heads.

As you correctly stated, tin is the crux of it. Can modify tin but PITA and new tin pricey and not yet available new last post I saw from whomever was supposed to be making repop.

[nditiz1]

So the original plan was to rebuild the 1.7 heads. I talked with a local shop and they said after valve job and opening the heads for bigger p&c I'd be at the cost of brand new AA heads.

Without going to a 2.0, I'm only semi invested and a top end is quick work vs opening the case. Bearings look good to me (IMG:style_emoticons/default/biggrin.gif)

So why again do I need to involve a machine shop for the 1.8 heads? Are the stock 1.8 opened up to 94? Does AA sell heads that are bolt on for 96?

[Superhawk996]

Friends don’t let friends play with 1.8L’s.

I have zero hands on experience with 1.8L’s. And some of them even had this funky thing called L-jet?

Regardless. 1.8L is a 93mm bore - not 94mm like stock 2.0L. So I THINK that sets up the OD of the cylinder such that you still have to open the head to get to 96mm cylinders. This is probably the 2mm discrepancy between openings 103 vs 105?

I do have a set of 96mm AA cylinders in storage if you need a measurement. Likewise, I’m sure AA Perfoemance should be able to clear up with a phone call with absolute certainty . . . Or a 1.8l guy will chastise me. Rightly so. (IMG:style_emoticons/default/happy11.gif)

[mate914]

So the original plan was to rebuild the 1.7 heads. I talked with a local shop and they said after valve job and opening the heads for bigger p&c I'd be at the cost of brand new AA heads.

Without going to a 2.0, I'm only semi invested and a top end is quick work vs opening the case. Bearings look good to me (IMG:style_emoticons/default/biggrin.gif)

So why again do I need to involve a machine shop for the 1.8 heads? Are the stock 1.8 opened up to 94? Does AA sell heads that are bolt on for 96?

I think both heads will bolt up to 96mm jugs. I can look tomorrow in shop. You would be building a 1911cc, next best thing to a 2056cc..
I hope to see you at Carlisle.

Matt

[Superhawk996]

Just going to post this - take as one man’s opinion

I wouldn’t not open the bottom end and do bearings etc after a dropped valve. If it is truly all well and good it can be put back together with those good bearings (IMG:style_emoticons/default/poke.gif)

The dropped valve is symptomatic of an abused engine. To put money in new heads and not redo the bottom end . . . I couldn’t bring myself to do that. Engine is out, had a hard life, probably other issues not far down the road.

But that’s just me and in my opinion explains why we see so many stories on here of dropped valves, rod knocks, and T4 engines that just don’t seem to last.

I won’t hold it against you if you don’t but felt compelled to to offer that perspective.

[914sgofast2]

The quick and dirty thing to do would be to buy a new set of the 1.8 liter heads, since they won't need to be fly cut for the outside diameter of the 1911cc P&C kit's cylinders. Then remove your connecting rods and take them to a machine shop so they can straighten the rods and install new piston pin bushings. (You also have to buy new piston pin bushings, but they are relatively cheap).

If you are on a tight budget, you could then just reinstall the connecting rods with the old connecting rod bearing shells, but I would never recommend it unless the old bearings were perfect. It is better if you also install new connecting rod bearing shells when you put the rebuilt connecting rods and new pistons back into the engine.

Many "internet keyboard mechanics" are now writing that the Silverline brand of connecting rod bearings should be avoided because they are poorly made. (I have no opinion or experience with using Silverline brand bearings, so I will not opine on their claims) However, I suggest you start looking for a set of connecting rod bearing shells made by Mahle, Kolbenschmit, or Glyco -- and preferably made in Germany (the gold standard) or in Brazil. Avoid Chinese made engine bearings at all costs.

At all costs avoid the temptation to put a bigger than 96mm sized set of P&Cs in your engine. If you are still running the Djet FI system, the engine will never run correctly. If you are running carbs, then you will spend many hours and lots of money trying to tune the carbs and find the right jet sizes to work with the larger displacement. In addition, going bigger than 96mm piston sizes creates engine air cooling issues and oil cooling issues.

[nditiz1]

What is the need for rebuilding the rods?

This would be a budget build top end. Is it merely the fact that I'm already so close what is a few extra dollars to make sure they are good? Also, who do you recommend i send them too?

[euro911]

I have all my machine work done by European Motor Works out here in CA, but they're really close by. I'd think any reputable machine shop who works on VWs near you would do just fine.

[Superhawk996]

What is the need for rebuilding the rods?

When valves and/or seats drop and smash around that is never good for the rods.

At a bare minimum not good on road small end bushings. The harder the hit the more it may damage rod bearing.

Dropped seat usually to a lesser degree. They (the seat or the cockeyed valve) still usually hit piston but just don’t have bigger parts thrashing around like a complete valve drop. Since you were at least potentially considering reuse / repair of the 1.7L heads I assumed you have dropped valve seat not a valve as opening post suggests. (IMG:style_emoticons/default/confused24.gif)

At worst bent rod.

[dr914@autoatlanta.com]

we do 1911 96mm and new 1.8 heads

So I'm debating doing the top end on my 1.7 I recently dropped a valve on.

Looks like I can buy all items from AA performance. Can I just buy the 1.7/1.8 96mm P&C and the 1.8 AMC heads and call it a day? I'm getting confused on what I read about opening to 105mm bore on the 1.7 heads for 96mm Pistons. The AA website talks about modifying heads to 103mm bore. I guess I could also just use 2.0 heads, but my tin wouldn't match.

Sorry for being dumb...

[nditiz1]

The spark plug end was destroyed. Bore scope shows the top part of the valve in the chamber, which is preventing the engine from fully turning over. I'm actually surprised it was still running for 15 seconds before dying, which probably didn't help the matter lol.

Ok rod rebuild into the mix.

[mepstein]

What is the need for rebuilding the rods?

This would be a budget build top end. Is it merely the fact that I'm already so close what is a few extra dollars to make sure they are good? Also, who do you recommend i send them too?

I would send them to Billy/Performance Auto Works.

We use new Pauter rods 95% of the time but if we are reusing rods, they always get rebuilt.

[Robarabian]

I did this. 1.8 heads work fine. It all fits. Use the AA piston kit. Runs like a champ on stock FI with stock cam. Adjust MPS a bit and it’s amazing.

[JamesM]

So the original plan was to rebuild the 1.7 heads. I talked with a local shop and they said after valve job and opening the heads for bigger p&c I'd be at the cost of brand new AA heads.

Without going to a 2.0, I'm only semi invested and a top end is quick work vs opening the case. Bearings look good to me (IMG:style_emoticons/default/biggrin.gif)

So why again do I need to involve a machine shop for the 1.8 heads? Are the stock 1.8 opened up to 94? Does AA sell heads that are bolt on for 96?

PMB sells EMPI heads with Manly valves now. 2.0 plug location though. They will be bolt on for the 96s

Out of the box the valves on the AMC 1.8 heads are not great.

https://pmbperformance.com/products/empi-su...807e7&_ss=r

[rfinegan]

Jake Raby put a paper together on upgrading a type 4 motor and the parts that can be reused...let me see if I can find it...

http://www.914world.com/bbs2/lofiversion/i...hp?t141448.html

[Superhawk996]

Jake Raby put a paper together on upgrading a type 4 motor and the parts that can be reused...let me see if I can find it...

http://www.914world.com/bbs2/lofiversion/i...hp?t141448.html

(IMG:style_emoticons/default/smilie_pokal.gif)

[930cabman]

The spark plug end was destroyed. Bore scope shows the top part of the valve in the chamber, which is preventing the engine from fully turning over. I'm actually surprised it was still running for 15 seconds before dying, which probably didn't help the matter lol.

Ok rod rebuild into the mix.

100% teardown, inspect all parts, add new parts as needed.

After a catastrophic failure, a complete teardown is in order

(IMG:style_emoticons/default/sawzall-smiley.gif)