engine rebuild

[herr_sparky]

Im rebuiling a 1.7 out of my '74 fastback, and I want to make a couple of changes. Im interested in hydraulic lifters specifically, and I want to be sure that I get everything matched up proper. what else besides the cam, lifters, and pushrods are needed? Is the expense worth it? Ive not yet had my case inspected professionally, but the obvious signs of wear are extreme. the old solid lifters have worn into a nearly prismatic shape on their sides, and the foot is so concave its mushroomed. If the lifter bores have worn beyond the limit is the whole case shot? The stock hyd. cam from a 2.0L suitable for a smaller displacement with stock FI and valve sizes? I would also like to install 93mm P&Cs, and while the heads are serviced, are there limitations to the valve sizes I can use with this kind of cam and the larger pistons? This is only my second rebuild, and I still want to keep things close to stock, and I dont know enough to be able to figure out what will work together right. If Im lucky on ebay Ill have a full set of 33mm Sodium filled exhaust valves to install, so that limits the valve sizing already. Ill probably end up going with the stock crank & rods, too. suggestions?

[ray greenwood]

Hello...The 33's are barely adequate for a 1.7. They were a major tuning restriction. I would go to 36mm exhaust. 41 or 42 for intake. What kind of injection? I am assuming that if its a 74..its most likely L-jet. If its an early 74...and possibly has D-jet...you cannot properly time the injection with hydraulics...and the resulting difference in valve opening points, so you cannot use it with D-jet. I would stay away from the stock cam...either solid or hydraulic. The surface hardening and angle on the lifters was flawed and is a source or early failure...and has not been corrected. Use a web cam and the matching lifters, solid or hydraulic. Have the lifter bores checked. A reputable shop can steel sleeve and hone them for you. Check on prices. It may be cheaper to get a new case...maybe not. It is an excellent solution. Havn't had it done in a few years...don't know who to reccommend. And yes, if you go hydraulics, you will need the pushrods. If you are boring heads to 93 and stick with the stock injection...and keeping stock valve sizes...go with fuel injected 1.7 heads. Better combustion chamber. I think all of the stock sizes of valves are too restrictive. Compression should be around 8.2-8.5:1. The combination of better valves and cam with the better compression really make the stock injection run so much better. Ray

[herr_sparky]

so the hydraulic lifter/cam setup wont work with D-jet? what system does it work with? would I have to use carbs?

[ray greenwood]

Hello, The hydraulic lifters will work with carbs or with L-jet. Yes, you can put them on D-jet...but heres the problem. With D-jet, your injection timing is taken from the distributor...which is timed from the cam. That in itself has some problems. The valves being timed to the cam leads to the valves having to be spot on. The type 4 has short steep ramps on the cam. The timing of D-jet is problematic enough on two of its cylinders. You will find that just being .001-.002 off..or different from cylinder to cylinder equals quite a bit of distributor/cam rotation in degrees. It results in more of the injection being at the wrong time in relation to the intake valve opening point. It causes rough running and poor sensitivity to fuel mixture adjustments. The manuals made note of this problem in type 3 and 4 with D-jet...but did not put enough emphasis on it. Its really important. If I can get my modified distributor cam worked out this month...it will become a whole lot less important...but thats in the works for now. I have found the best way to keep slop out of D-jet for best running, is to set the valves cold...to factory. Warm the car up very well...and adjust them hot. You will find them all different...because they grow at differnt rates. Set them all equal once they are hot. I have found that the hot setting (depending on pushrod material, seat material, valves etc...) to be between .0015 and .0025". All valve adjustments on D-jet MUST be done AFTER setting the timing and advance...dead on. This makes it run a whole lot better and smoother. Hydraulics, although they are self adjusting and can hold their tolerances very well...cannot be set as accurately....and I mean by that...with certainty. If you have D-jet...keep it. I like it better. More tunable than L-jet..and more dependable in my opinion. I would use the web cam #73 and the lifters they sell, with it. Ray

[MASSIVE TYPE IV]

Solid lift.....Hydro has absolutely zero benefit in my opinion, all they do is promote neglect!
"To place a hydraulic valvetrain into that aircooled engine is like installing a hand grenade in the valve cover!"

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Jake Raby
Raby's Aircooled Technology
www.aircooledtechnology.com

[richard411412]

Hello, I went the route you are considering: rebuild with hydraulic lifters & cam and increase in piston size on my '72 411 with D-jet. The car was never very 'peppy' to start with, and after the rebuild it is even less so. I switched to the hydraulics because I thought it would protect me from another broken valve, which led to the rebuild in the first place. I used my left over cam and lifters (and some of the pistons) to rebuild my '74 412 with D-jet on the extreme cheap. I know it is wrong to reuse lifters, but I kept them matched to their original bores. Compared to the 411, the 412 with solid lifters and less displacement is much more energetic. I wish I had known about the Weber cam and lifters, I would have gone that direction. I wonder if you can use a hyd. cam with solid lifters of the correct length? Perhaps Ray would know.

[ray greenwood]

Hello...no you cannot use the hydro lifters with the solid cam or vice versa. They have a difernt curve to the lifter lobe. Also you cannot use the hydraulic with D-jet. It is also unnecessary...and will net you Zero HP with either D or L jet. The 1.7 L 411 and 412 engine were identical with D-jet. 8.2:1 compr....same cam...domed pistons. This changed when L-jet started in 74 with the 1.7 and then the 1.8. The D-jet 1.7 had the best HP of all of them...except the 2.0 914. It had 82 stock. The problem sounds more like the common weak ignition and proper tuning of the fuel mix. Check your compression...adjust the valves...first cold...then re-check when hot...making sure they are in the .002" rangwew when hot. The ignition needs to be replaced with some thing like a pertronix. The stock was very weak. Most of your problems will be in fuel mixture tuning. Let me know if I can help. By the way...teh problemswith the valves in the original 411...on 1.7's..had to do with a weak connection at the stem and head. Just replacing the valves in the 1.7 will cure this from happening again. It had nothing to do with the lifters. Ray

[richard411412]

Thanks for the info! It has answered a five year old question for me: why did I get LESS power with more displacement when I rebuilt the 411. Here is another old question for you, why do the electronic ignition folks, like pertronix, say 'not for use with fuel injection' in their ads? I've wanted to get one, but that line has kept me away from it. Another real basic question, in the books it says to adjust the valves with hydraulic lifters, by turning the adjusting screw 'two full turns' after it just touches the valve. I have assumed this meant 360 plus 360 degrees, or 720 degrees. Is this correct? Also, is there a more accurate way to do it cold? I am going to try the hot adjustment that you suggested. And one other question, is there any adjustment to fuel pressure or to the pressure sensor that would help with the air/fuel mixture since the displacement, and presumably the amount of air going into the cylinder, has been increased? I don't have an exhuaust gas analyzer, but I do have a fuel gauge. Is the compression ratio measured with a compression tester reading divided by the CC's? Thanks!