gumby's '79 X-1/9

The hi-comp pistons from the second engine are similar to others I have seen. My guess would be 12:1 compression. Clearly, somebody put some time and effort into building the engine. A balanced crankshaft and high compression, forged pistons would tell me there is likely an upgraded camshaft as well. Have the ports been worked?
Big valves in the head, but ports appear untouched. I still see casting lines and the stem bosses have not been shaped or smoothed. No cam box on this engine as delivered, but I have the 35/75 from the broken engine to carry over.

12:1 sounds fun :cool:
 
Yeah, should have noted the BV head. Odd that somebody went to the trouble to convert the valves but not port. Some port work would help the BV head breath. Without porting the velocity dynamics will suck. The air will stall at the valve head. I would suggest some competent port work. I really like the 35/75 cams. Good choice.
 
On a bit of a sidetrack while waiting for engine stuff. Spent a little bit of time hunting my electrical issues today.
The left front turn signal was inop, missing ground. Wiggle test shows I need to clean and address the ground point in that corner. Right headlight dim, same wiggle test, same result, weak grounding.
Rear lights had intermittent issues; different each time I checked. When the 4" LED trailer lights would work, I could tell they were intended to show brake/turn/park with both lights on each side. Looking at pics of other X's I see the turn signal is separate from the stop/park lamps. This made me think there had to be something going on in the wiring as the turn signal needs to cancel the brake input for this arrangement and that is not how the X was originally wired.
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Sure enough, I popped both tail panels out and found this gem! These are used to convert separate signals into a single output for trailers. They are also notoriously JUNK.
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I checked the wiring before the converter and found all the signals are present. I bench tested the tails lights and the right side are missing multiple LEDs within each light. Left side OK. I will grab a couple more 4" LEDs and rewire this as a separated signal format to eliminate the converter.


On the engine side of things, I compared parts between each engine relative to setting up the cam, and sorted all the shims I have on hand. The cam box from the broken engine has been shaved. The BVH has not been shaved at the cam box face(at least not as much as the head from the broken engine). The valve stems in the BVH have been ground on and it was wearing a thick cam box gasket as delivered. These indicators lead me to believe the stems may be taller than standard. Setting this cam up in a shaved cam box on an unshaved head with unknown stem lengths could get interesting! I have several bucket shims and a couple of Volvo T5 heads that also use 33mm shims which I have not broken down yet. I have a couple unshaved cam boxes as well that I could swap the 35/75 cam into if needed.
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Back to thinking about engine gaskets. I have looked at a couple vendors but am not sure who has the best quality gaskets; head gasket especially. The full kits from Vick's only indicate two options in the menu, and I am uncertain how they would know if my 1500 is 10bolt or 14bolt without me calling them. Do these guys need phone call follow up or are they on the ball with online orders? MWB on the other hand, shows several options for their complete gasket kits which gives me warm fuzzy feelings about getting the right parts the first time. Is it worth the extra money, is the quality better? I am looking for experienced recommendations from you guys who have used products from these vendors, please.
 
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This may not offer a full answer, but when a reground cam (or even some new aftermarket cams) with a smaller than stock base circle is installed, the extra gap can be made-up be either thicker shims or by shaving the cam box down. The second option is often chosen, but its common to intentionally 'over-shave' the cam box more than required. This results in thinner than stock shims being required. Grinding down the shims or the valve stems may have been done to accommodate this.

If all of that seems odd to you, well it is in my opinion. The theory is to intentionally do this so the shims can be made "lighter" by grinding them down, in the hopes of making the valve train 'higher performance'.

You will have to take a lot of measurements with an unknown cam box (could be shaved a lot, or a little, or not at all), and possibly unknown valve stem lengths. Then determine the correct shim thickness.

Regarding head gaskets, there seems to have been a lot of problems recently with new head gaskets blowing shortly after installation. You might want to read through some of those threads to make your own opinion as to the reason for this.
 
I did get some tail light bits ironed out.

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Ran out of connectors, so only one side is done but it feels good to actually be putting something back together on this car.


I moved the slicks off the turbines last week and got the street tires mounted up

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Gonna need some flares if I wanna mount up the autoX wheels from the truck
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but it feels good to actually be putting something back together on this car.
Looks like you are making progress. These cars can test your patience at times.
Ha, that last picture reminds me of a drag race X1/9 I've seen online:
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Finally, finally, back on the engine part of this project. I ordered gaskets and tools from MWB, Vick, and Aircraft Spruce. All three packages showed up today!
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I headed out to the shop with my new parts, pushed the pistons out of the bores, and decided I should paint the block real quick. 2hrs later...
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Then I started deburring pistons.
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Not knowing who built this engine, and having never been run, I felt that I needed to treat it as though I had just bought a bunch of parts and was assembling fresh. I pulled the rings off the pistons and found the end gap was way too tight when fitted in the bores. 0.006-0.007" on all top and second rings. Time to phone a friend. He brought over his ring filer and we got end gaps set. We also popped a couple valves out of the BVH, inspected the pockets where the larger seats were cut in(needs work), and checked valve spring pressures.

There will be a lot of grinding/sanding going on this weekend and next week to blend everything in nice. Then lots of cleaning before assembly. I will check lower bearing tolerances after everything is cleaned up and ready to go back together.
 
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When a chassis guy wants to play engine builder, it is nice to have a friend with a serious motor program. No 'making due' with screwdrivers and hammers this time

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Moving along, I spent a few hours blending the pockets behind the valves into the larger seats and general smoothing in the combustion chamber area. Nothing too crazy, but there was some ugly that needed eradication. Apparently I don't have a before pic...I am calling this good enough

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While messing with the head, I got to thinking about the goofy half bolted, half studded connection to the block. I am not a fan of mixing hardware like this for a headgasket clamping situation; doubly so when they are different lengths. There is a documented ARP solution that involves a 4g63 stud kit and a little machine work. I figured if I would have to do machine work either way, why not use the studs from both my engines and fix up my own solution? The ARP studs need about ¼" taken out of the tall bosses on the head. The factory studs are shorter than the ARPs, and I would need to remove a bit more material. Looking at the casting, I could see where my plan might hit water but I decided to send it anyhow.

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So, yeah, there's that. Welded up the boo-boos, re-machined those locations, and ended up with this

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Gathered up ten 12mm hardened washers to replace the powdered metal parts, and should be good to go. Fingers crossed, I should be final cleaning parts and hope to begin reassembly tomorrow.
 
Come a long way!

Just noticed this engine under the bench: You also a Volvo guy? Looks like a WhiteBlock to me :D

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