83 Monte gets a stronger heartbeat.

B

bowtiebutler956

Not-quite-so-new-guy
Oct 10, 2017
47
18
Hello all. I bought my 83 Monte a little over a year ago, and have really enjoyed this car. I posted a thread here just after I purchased it. https://gbodyforum.com/threads/83-monte-carlo.65594/#post-587211
I have done a fair bit of work over the lat year including a complete suspension rebuild front, and rear including new stock height coil springs. I removed the ecm, computer quadrajet, and computer distributor. I packed them safely away in case I want to return to stock. It now has a Jet 35001 quadrajet, and a MSD street fire HEI. It also received a set of stainless steel headers, and a true dual exhaust which required the install of a Jegs double hump trans crossmember. While this did help the performance of the original 305, its still seriously lacking in the performance department, So, that is what is going to be addressed next.
Let me start by saying the car is a very rust free , almost all original looking old car, and I really like that look, so the new engine needs to follow that theme. This 383 will need to look like the old stock 305 (to all but the but the sharpest enthusiasts) in every way right down to the satin black paint. The 383 is one I picked up from a friend several months ago. It was professionally built by a place called Promotor out of Indiana. He ran it in his S10 for about a year, and loved it, but he decided to spray it with nitrous, which it wasn't set up for ( ring gaps to tight), so it lifted the ring lands out of several pistons. Rather than fixing it he went with an LS swap, and sold me the engine for $250. While the pistons were shot, the cylinders still looked pretty good, and after a quick hone they should do well. The crank, and rods are both Eagle 4340 forgings, and are overkill for what I'll be doing with them. The engine was balance by Promotor , but was using speedpro forged flat tops. The piston I'm using are dished to keep the compression down. They are a few grams lighter than the flat tops, which will thow the balance off a little, but should be fine for a low rpm street engine. The heads aren't anything special, just a pair of Engine Quest cast iron IMCA heads that I did some light clean up below the valve seats, and were cc'd at a rather small 62cc combustion chamber, and is the reason for dished pistons. I will add pics of those soon. The cam of choice will be a mild Lunati VooDoo 262/268 with 468/489 lift flat tappet which should make good vacuum, and perform well in my application. The intake is an old GM Bowtie off a ZZ4 that been hanging around the shop for years now. It has the EGR provision which will help with the stock appearance.
I'm not sure how well the qjet will perform with my cam choice, but if I have to it can be sent back to Jet to be custom taylored to this setup. Anyway, I've rambled on long enough. Here are a few pics, and I will post more as it progresses. Thanks
Matt
 

Attachments

Last edited:
565bbchevy

565bbchevy

Geezer
Aug 8, 2011
6,482
113
Michigan
I personally would have had the rotating assembly rebalanced just for piece of mind besides when you decide you want extra power later on and want to add a roller cam and some "black painted" aluminum heads you know it was going on a well built bottom end.
 
B

bowtiebutler956

Not-quite-so-new-guy
Oct 10, 2017
47
18
I personally would have had the rotating assembly rebalanced just for piece of mind besides when you decide you want extra power later on and want to add a roller cam and some "black painted" aluminum heads you know it was going on a well built bottom end.
I certainly can't argue with that, and you obviously know how these hobbies progress. :giggle: However, once I go to the machine shop, then I may as well take my still Virgin STD bore 4 bolt block there as well, so it can be be bored .030 so that I have perfect cylinders, then I'd want to have it parallel decked to a zero deck hieght, etc.. Before I know it the engine that was only costing me 100's is now costing 1000's.:giggle: Your still right, but I think I'll try the low buck approach first, and see how long I'll be happy with it.
Matt
 
565bbchevy

565bbchevy

Geezer
Aug 8, 2011
6,482
113
Michigan
  • Like
Reactions: bowtiebutler956
Clone TIE Pilot

Clone TIE Pilot

Royal Smart Person
Aug 14, 2011
1,988
113
Galaxy far far away
With your old 305, the stock CCC Qjet would likely offer better performance than the reman Jet carb that has been converted to a generic tune they call high performance. Qjets must be built to match the specs of your engine, not just generic tunes like most aftermarket carbs. Alot of places that "recalibrate" or "reman" Qjets just cobble together mis matching cores, plug the air bleeds, and install fatter jets to make them run rich and mask build issues. Running a little rich can hide a boatload of problems.
 
B

bowtiebutler956

Not-quite-so-new-guy
Oct 10, 2017
47
18
So are you saying you only have a 377 sbc? 4" bore with 3.75 stroke.
No, the block in the pics is a .030 over, but I have a STD bore 4 bolt block with the correct pass side dipstick that I had originally planned to use for this build, but after buying this engine from my friend, I realized I could build a decent 383 for very little money using mostly parts I had laying around. The only parts I really had to buy for this engine was a set of pistons, and a camshaft. Thanks
Matt
 
  • Like
Reactions: fleming442
B

bowtiebutler956

Not-quite-so-new-guy
Oct 10, 2017
47
18
With your old 305, the stock CCC Qjet would likely offer better performance than the reman Jet carb that has been converted to a generic tune they call high performance. Qjets must be built to match the specs of your engine, not just generic tunes like most aftermarket carbs. Alot of places that "recalibrate" or "reman" Qjets just cobble together mis matching cores, plug the air bleeds, and install fatter jets to make them run rich and mask build issues. Running a little rich can hide a boatload of problems.
I don't think the factory CCC carb would work very well with my cam choice. I agree with you, that my current Qjet may not like the engine I'm building either, but Jet isn't your average carburetor rebuilder, and I can send it back to them to be customized to this combo. I have also given thought to sending it to Sean Murphy who is a legend with Qjet tuning. Initially, I'll see how it runs, and will decide from there. Thanks
Matt
 
  • Like
Reactions: Griffin84ss
B

bracketchev1221

Master Mechanic
Jan 18, 2018
454
63
The balance will be fine. Being the crank was balanced for a heavier reciprocating weight, effectively by taking the weight out of the piston you have induced an "overbalance" in the crank. It is a common practice in high rpm race engines. As far as the cam, in an engine that size, it will be almost unnoticeable. I think the carb will be fine.
 
  • Like
Reactions: bowtiebutler956
B

bowtiebutler956

Not-quite-so-new-guy
Oct 10, 2017
47
18
The balance will be fine. Being the crank was balanced for a heavier reciprocating weight, effectively by taking the weight out of the piston you have induced an "overbalance" in the crank. It is a common practice in high rpm race engines. As far as the cam, in an engine that size, it will be almost unnoticeable. I think the carb will be fine.
Thanks for the info on the balance, and I'm hoping the carb works well.
Matt
 
B

bowtiebutler956

Not-quite-so-new-guy
Oct 10, 2017
47
18
Here are a few more pics of some of the part that will be going on the engine. None of them are pretty, as they're all used, but should work very nice for this budget build. The heads already have nice bronze valve guides, guide plates, and screw in studs. I only cleaned up the valve pockets below the seats. No other port work was done. I like that the ZZ4 intake has the firing order on it like an original intake. The balancer is a 6.75 Professional Products unit that came with my 383, but its already been cleaned, and painted. The rocker still need to be cleaned, but are in good shape. There is also a couple pics of my Qjet including the note on the box saying its not setup for a performance cam, but I'm still going to try it first. I do appreciate all the comments from you guys. Thanks

Matt
 

Attachments

  • Like
Reactions: fleming442

Please support GBodyForum Sponsors

Classic Truck ConsolesDixie Restoration DepotMike's MontesP-S-TSouthside Machine PerformanceUMI Performance

contact[email protected]for info on becoming a sponsor