I have this engine in my 84. Looking forward to testing this summer. Going to find out how strong these motors are....or are not. Should be fun. Cheers
Yeah, that looks really clean.....So what tranny are you hooking that obvious torque monster to????? I am assuming an automatic but I'm sure there are plenty of manuals that would be fun to blow up...... I had just put a supercharger on a rear rotary set-up (you know, they don't make much torque right?) to a heavily modified VW tranny with all the best of the best in it. First good launch..... tranny held fine but smoked the clutch, twisted an axle and broke 2 HD race prepped CV joints. Superchargers just change everything.......
I assume your alternator is the tension adjustment, so that bracket might need reworking, but this would be a much better belt path for this setup. Even then, I would make sure the idler pulley isn't just bolted to the aluminum bracket off the backside of the water pump as the torque needed to pull the supercharger load would likely snap it off.
Never had any belt slip. Supercharger has more wrap then the set up it uses for the SBC. Idler pulley isn't bolted to the water pump. Goes through and bolts to a bracket that is bolted to the head. If I have any slip at the track I'll let you know.
Car is a 84 Fiero. Transmission is a rebuilt 4T60 with shift kit and 2800 stall converter with 3.73 gears.
[This message has been edited by Johns 4.9 (edited 04-05-2019).]
fieroguru, After looking at that idler bracket again, I agree with you about it being too weak. I think a steal bracket is a much better idea, good call. I think I will fab one up before I hit the track. As far as the belt path, looks good but it would hit the front of the water pump housing. Yeah, I tried at least a dozen variety of paths and brackets and the front of the water pump housing always gets in the way! Very frustrating. So I agree its not ideal but it is with in the physical limitations of the water pump housing. So as "much wrap as possible" is limited by the configuration of the water pump housing in this situation. There is still a lot of trial and error with this set-up. If it becomes a problem I will address it them. Thanks, man! Cheers
[This message has been edited by Johns 4.9 (edited 04-05-2019).]
While the 4.9L has been boosted and has performed well (12 sec 1/4 mile times) ; I don't believe that its the best engine for adding boost. The cylinder sleeves are held in place only by the heads. Adding boost puts even more stress on this design anomaly. I cannot say that supercharging won't work as you are using a smaller blower ; I'd just be concerned with the long term reliability. This is of course is just a opinion and the long term result may prove me wrong. Very nice job on the installation.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
I would not be concerned about the sleeves as diesel engines have sleeves that are held down in place by the heads
My comments are based on actual case histories of those that modified this engine. Many of them were reported here. One guy on this forum guy used a 75 hp shot of nitrous and ended up with water in the oil. It may be that a stronger copper head gasket was needed. Again I cannot say that boosting will not work but it may depend on how much boost is applied and how hard the engine is pushed. I guess that we will see, but my opinion is that this engine isn't the best platform to modify for more power. .
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
i just look at it different and i see that as a fastener problem of not clamping the head down tight enough as the fasteners are not strong enough or not enough head bolts but these engine use a wet sleeve design like a diesel from what i remember but no matter what every engine has its limits on what they can and can not take
I am going to have to agree with "engine man" in this case. I am more concern with head bolts and head gaskets then I am with the sleeves causing a problem. But failure is part of the process and I am expecting some type of failure so I cam build the next motor stronger. I just rebuilt his motor. Its a 89 4.5 short block with 92 4.9 heads. This yields 8 to 1 compression. The 4.9 heads have the bigger valves and ports.
[This message has been edited by Johns 4.9 (edited 04-05-2019).]
how much boost are you shooting for as i would think 6 to 8 pounds would be about max with stock pistons as i think those are just cast pistons and not hypereutectic pistons
fieroguru, After looking at that idler bracket again, I agree with you about it being too weak. I think a steal bracket is a much better idea, good call. I think I will fab one up before I hit the track. As far as the belt path, looks good but it would hit the front of the water pump housing. Yeah, I tried at least a dozen variety of paths and brackets and the front of the water pump housing always gets in the way! Very frustrating. So I agree its not ideal but it is with in the physical limitations of the water pump housing. So as "much wrap as possible" is limited by the configuration of the water pump housing in this situation. There is still a lot of trial and error with this set-up. If it becomes a problem I will address it them. Thanks, man! Cheers
I broke one in a N/A application, which is why it is suspect for booster application. On one swap I made a new steel bracket, on another one I reinforced the back side as part of my alternator bracket.
Here is another belt path that might work. It takes a little trimming around the timing tab and scope tube, but I used a similar belt path on another 4.9 swap:
Engineman, Yeah, 8 lbs is what it set up to run. I already have a new set of hypereutectic pistons for the next engine. I don't think nitros is a good idea with cast pistons for this engine.
No, no particular package. I based my measurements on the depth of the bolt holes in the block and the length of the bolts. Then I figured out what size stud would work. Steel is grade 10.9 or stronger. I need the main cap stud kit for the stud girdle that is going in with this engine.
No, no particular package. I based my measurements on the depth of the bolt holes in the block and the length of the bolts. Then I figured out what size stud would work. Steel is grade 10.9 or stronger. I need the main cap stud kit for the stud girdle that is going in with this engine.
Got to give you credit for addressing the possible head sealing issues with studs. I am inclined to believe that it will work. As for the main caps I believe that you should be OK with those stock. There was a guy on this forum (PBJ -IIRC) that turbocharged an EFI 4.9L and ran mid 12's in the 1/4 mile. The crank held. This seemed to prove that boosting helped overcome the restrictive ports in the head that gives the horsepower curve a low redline. Since it looks like you are going with an old school distributor and carb; IMO the biggest challenge might be the tuning. In the early days I've handled timing on a supercharged V8 by restricting the total advance by limiting the travel of the weights. This does little to tailor the timing curve to all running conditions. It can limit the total advance which is probably OK for the strip. I'd give some thought to EFI. You've done some really fine work on your engine and showed some real skills. Many of us will be following this post with enthusiasm. Hope that it meets your expectation.
------------------ " THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite. "THE COLUSSUS" 87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H " ON THE LOOSE WITHOUT THE JUICE "
Dennis, Thank you for the kind words about my build. The reason I am installing main cap studs is so I can add a stud girdle. This is the AutoCAD drawing of it. Just need to get it cut out now. I have given a lot of thought about the timing. I have a vacuum advance set up on the distributor that retards the timing under wide open throttle and full boost. Detonation can be a big problem for cast pistons! Still working out the final details on that but the vacuum canister is adjustable.
As far as the belt wrap goes, it hits the water pump! I appreciate the enthusiasm but there is only one way the belt can go up to the supercharger. On the left hand side of the pump. Its hard to tell from the pics. Like I said I tried over a dozen ways and this way is a compromise for all the variables. Not ideal but still no belt slip. Thank you for your efforts!
[This message has been edited by Johns 4.9 (edited 04-11-2019).]
I have this engine in my 84. Looking forward to testing this summer. Going to find out how strong these motors are....or are not. Should be fun. Cheers
To that bolt just above your steel waterpump cover and just outside the belt (Your pic doesn't show at work, I'll make one calling out the bolt when I get home).
Ernie, I have been pretty busy working, but that car is getting new headers and dual exhaust right now. I have new fuel injection now on my 4.9 Fiero. Cheers
ould be fun.
