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| didenpx |
Feb 10 2026, 12:35 PM
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#1
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Member ![]() ![]() Group: Members Posts: 121 Joined: 1-September 23 From: Usa Member No.: 27,556 Region Association: North East States
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Last year I bought a project car that came with multiple parts cars and a partially disassembled GA block engine that the guy I bought it from thought was just a stock 2.0 (he got it along with another parts horde years previous and never touched it).
It came with the 3-4 cylinders and head pulled and no valve train in the head. After examining it thoroughly with the help of an experienced air cooled engine builder friend we (mostly he, since this is my first go round) determined that it is a stock stroke engine and the 3-4 head was likely pulled because of a valve spring failure of #3 exhaust valve. That spring boss is peened so that a spring will no longer fit over it and the valve guide is worn loose in the bore. Pistons are JE SRPs and based on the fact that they have no laser etched batch markings were produced prior to 2004. Assume the build was done in the late 90s to early 00s. The heads have been heavily ported and polished and the combustion chambers have been opened up to about 64.5cc (was marked on bottom of heads and we confirmed my titration). We are not yet certain the 3-4 head can be saved but at this point we believe it can (machine shop visit upcoming). Neither head shows visible signs of cracking etc. Exhaust valves are 38mm and intakes are 44mm and stainless but will need replacing for peening of the retainer grooves. Lifters are pitted and require replacing. We split the case and it has not been previously bored and all bearing saddles look good. Connecting rod side clearance is well within specs (.008” to .011”). The crankshaft has welded counterweights (suspect maybe DPR). Camshaft has excessive end play and the lobes are unevenly worn. It also has excessive end play. I haven’t been able to positively identify it, but believe that based on markings on the timing gear it’s a Norton N3. At any rate it needs replacing. Deck clearance is .050” and it appears to have been built to about 8.4 : 1 compression. If I go forward with building it, would be going dual Weber route and putting it in my 1975 1.8 driver quality restoration. I’d be aiming for 9.0 - 9.5 CR and a Raby 9500 or CB 2202 cam (preliminarily). I’d also be replacing pistons and cylinders with JE/cast iron combination from AA Performance. Would also go with external oil cooler kit (probably Chris Foley’s) Given that this engine was essentially free to me and looks as if it can be resurrected at relatively modest cost (assumign 3-4 head is viable) what are the pros and cons of doing this, and what alternatives are there to make use of this case in a different build (smaller cylinders, same heads?)? I’ve done a lot of reading and understand that 100+mm cast iron cylinders will not give the longevity that Nickies would (simply not a cost option for me). But if I build the engine carefully, don’t race it, and put 5K miles a year on it could I realistically expect to get 10+ years enjoyment out of it? What other options would I have to make good use of this case, crank, and heads if 103mm is a bridge too far? |
| didenpx |
Feb 10 2026, 12:41 PM
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#2
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Member ![]() ![]() Group: Members Posts: 121 Joined: 1-September 23 From: Usa Member No.: 27,556 Region Association: North East States
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| Ninja |
Feb 10 2026, 02:05 PM
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#3
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Member ![]() ![]() Group: Members Posts: 127 Joined: 25-September 25 From: Granbury Texas Member No.: 29,004 Region Association: Southwest Region |
What is the bore/stroke combination? (never mind, did the math, 71mm stroke)
Both the case and the heads have been bored oversize to fit the 103s. A smaller bore is possible, but the jugs will need to match the OD of the jugs you have. This will be an issue if you want to back date to 96s. Now, I've seen Nickies with smaller bores and hugely think jug walls that might be the ticket. They are NOT budget friendly. I'd guess what you have will lock you into 101-103 bores. That case has the windage cut outs in it and is slightly less strong than a none windage case (earlier). Neat critter to come onto for free. All the issues being addressed in the other thread apply to this but... http://www.914world.com/bbs2/index.php?showtopic=377215 You're doing it right! Checked deck height during tear down, have a good handle on the cam. Proper planning. |
| VaccaRabite |
Feb 10 2026, 02:50 PM
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#4
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En Garde! ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Admin Posts: 13,840 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region
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IMO - is it possible? Sure.
Is it probable that you will build a 10 year engine with 103s and cast iron cylinders? No, its not probable. If it was an AX car that would never be driven past the point of heat soak, sure. Chances go up. But if you want a car that is going to be happy and fun to drive 100+ miles, 103s are going to be a complete bitch to keep cool. The heads will get too hot and fail, just like it did to the guy that sold you the car. Zach |
| mepstein |
Feb 10 2026, 04:09 PM
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#5
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914-6 GT in waiting ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 20,420 Joined: 19-September 09 From: Landenberg, PA/Wilmington, DE Member No.: 10,825 Region Association: MidAtlantic Region
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I would build the engine around the right parts, not the cheap parts. Especially if reliability is your goal. I think there's probably a good reason why the oversized cast iron jugs aren't popular anymore.
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| URY914 |
Feb 10 2026, 06:06 PM
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#6
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I built the lightest 914 in the history of mankind. ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() ![]() Group: Members Posts: 131,017 Joined: 3-February 03 From: Jacksonville, FL Member No.: 222 Region Association: None |
Call Jake Raby and ask him what to do.
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