Need Engine rebuilding advice, 1.7 top end bad, need some options |
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Need Engine rebuilding advice, 1.7 top end bad, need some options |
brandomc |
Aug 4 2009, 12:53 PM
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#1
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Member Group: Members Posts: 113 Joined: 14-May 09 From: los angeles california Member No.: 10,363 Region Association: Southern California |
Hi Everyone, I am needing some advice for what i should do with my engine. I have a 72 1.7 Fi motor with 80k on it at least. The previous owner said that he put all new seals in it and ignition components, but as far as i can tell he did nothing. He also said that it just needed a valve job on the passenger side cylinder head. Also a big lie. when i tested compresson on the engine "after buying it" i found 0 compression on Cyl # 4. I decided to let a volkswalgon mechanic i know work on it since i thought all it needed was a valve seat or something like that replaced. Oh yeah, the engine did run, but not well. Anyways, the mechanic calls me over and shows me the carnige of my top end.
It isnt too bad i guess, but the head, piston and cylinder are shot on #4. The mechanic says that he will pull the pistons and cylinders and use his extensive knowlege of the engines to determine if the bottom end is good or not without disasembling. He did that and told me that the bottom end seems solid and he couldn't see anything wrong with it. He then said that he could get all the new parts for my top end for 1500+ 2000 for labor. I feel that it is worth it to do the labor myself and i know im quite capable, i just need to know the best option for parts, or if i should just start from scratch and build a "biger" engine. Does Raby have any top end kits for something like this? Any advice is appreciated. |
HAM Inc |
Aug 5 2009, 08:14 AM
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#2
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Senior Member Group: Members Posts: 846 Joined: 24-July 06 From: Watkinsville,GA Member No.: 6,499 Region Association: None |
I'd rather have the 1.7 heads for a 1911. Regardless of which heads you use, they will have to be rebuilt with new seats, guides, valves, springs, retainers, exhaust studs, etc. The 1.8 heads are WAAAY more likely to be cracked than the 1.7's, which means more time spent on repairs. The 1.7 heads have smaller intake ports than the 1.8's and really lend themselves toward a great low-end, torquey engine with good MPG. My personal choice for any street engine under 2.0 liters (I really like low-end grunt!) is hands down a pair of 1.7Q heads.
The damage to the head in the photo appears minimal. The seats all have to be removed anyway when rebuilding. That's just one less to pull out!LOL. You will need to go into the bottom end. The shock of the valve and piston collision and subsequent quench into the head will have damaged bearings at a minimum, and could have damaged the rod and crank, and possibly even the case. On top of all that you'll want to install a new cam and lifters anyway. Save yourselve head aches and see if you can get Jake to pull together what you need in a kit form. Combined with his build video you can do it yourself. |
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