I have a 1932 Ford roadster with a 327 Chevy engine. I believe the compression to be somewhere around 9 1/2 to 1 (flat pistons with 462 heads). The camshaft is a Comp Cam's nostalgia cam that supposedly mimics the 350 horse 327 from a '67 Corvette. I believe they changed a few things to get a little better performance out of it. The camshaft is very snappy once you have some RPM, but for off idle, it's a little hesitant/ sluggish. A buddy of mine suggested that a light car with that engine would like a lot of advance, quickly... I can't find anyone in my area with a distributor curving machine, so I'm going to buy the MSD spring kit and try the lightest ones to see what effect that has... Does that sound like a solid plan?
Before swapping out the weight springs... Make sure everything else is in order first. What do you have the initial timing set? If you are running a hotter cam, you should be running at least 12 deg. BTDC. Total timing if you are running a vacuum advance should be around 34 deg. (As a good start) Is the idle mixture set properly on the carb? Usually off the line hesitation is caused by a lean condition. You might need to richen the idle adjustment. Set the idle mixture with the highest manifold vacuum reading. If everything checks out, then recurving the distributor would help. Just be mindful that to light of a spring on the weights will cause the timing to stay advanced too long and the engine won't idle back down as soon as it should... causing a spark knock issue. You do not want that.
Put a vacuum guage on it and see what it tells you as you take off. A 327 in a light roadster should not have any low end problems.
Are you sure you don't mean total timing @ 34 degrees. What is your initial timing with the vacuum advance (if running one) disconnected and the vacuum port plugged? Does the engine crank ok once it is at running temp, or does it drag? Just wanting to make sure you've checked everything before modifying your mechanical advance in the distributor.
The 350 hp 327 had an 11.1:1 compression ratio; that's what the cam was designed for. You have somewhere around 9.5:1. I believe you are experincing what I did with an 8.5:1 compression LT1 engine. My long duration cam (Racer Brown 42R) killed the bottom end, but the engine would really scream on the top end. I ran the 42R with my 12:1 short blocks and had tons of bottom end. Switching to a shorter duration cam (Isky 505T)woke up the bottom end torque on the 8.5:1 engine. Lower compression engines do not make a lot of low end torque with a long duration cam.
Same with my 290hp crate motor. The cam in it is similar to the early 350 hp cam, but this engine is only 8.5 cr and runs fine on 87 octane. BUT, it is not a screamer off the line.
I'll dig up the specs on the cam, but I'm pretty sure it's a bottom end cam... When I talked to their tech on the phone about which cam to choose that was one of my criteria.
Whoops- yes... I think the initial timing is around 18°, but I could be mistaken. When the engine is hot, it cranks easily and fires right up.
that engine should easily take the 34 total, but just for grins before you get involved, try seeing just how much it will actually take before ping-some will go 36+ and run strong. Had one that took 36 total and that was its key. Just be sure you have all vac. sealed and disconnected when you get total. A dial back light is great for this. Yours might not take it, but its a cheap investment. BTW, do you know how much total is built into the distributor?
Recurving the mechanical advance has it's advantages. ( I've done several and had great results) But if you get the MSD kit, start conservatively with the middle springs. In any application I have had in the past, I have never used both light springs in a street application. Most of the cars I have worked on are heavier (Chevelles, Camaros, Tri Fives, Etc.) and your 32 shouldn't need the timing to come in to soon because of the weight of your roadster. If you have access to a slightly bigger carb ( 700-750cfm) it would help if you are running a L79 spec cam.
The way Ive always set up the distributor timing is to go from initial to full advance by 2100 to 2400 rpm. The old saying that 90 percent of carburetor problems are timing problems holds true. I would give it two degrees more at idle and see how it performs off file. If it smooths out there’s your answer. Then you can shorten the curve.
Found the cam card I remember now that I didn't go for the 350 horse 327 cam because the guy at comp cams said it was quite choppy
^^^^^^^ the right answer…. 5-6* advanced cam will light up the tires off idle with that cam in a 32…if your rear gear is near 3.00.
Dangit! I just installed my cam straight up and I almost advanced it 4 degrees because I have a double roller with a multi key way. Shoot!
It would have had a different feel if you did; jumps at the crack of the throttle. Many cam manufacturers put 2* degrees in when grinding street performance cams because it’s safe and gives the owners a slightly better performance. I like 6* on any 9-1 or slightly higher street build engine so I always check where it is out of the box. Before we had adjustable cam gears with removable windows on the timing cover and multiple crank gears I installed a lot of concentric buttons on the cam gears…
The goal is to destroy the tires off idle, which it already does if you goose the throttle and then step into it. My rear gear is 3.50 and I have 31" tires (TH350 automatic). I have a 2100 Comp Cams timing set which appears to have +4 and -4 option built in. I assembled it straight up and I'd have to have to pull the front apart to change it - think it's worth it? In the meantime, I think I'll mess with the MSD springs starting with the middle weight.
Looks that You are disappointed,, Your 327 is not that radical ,, You need to change parts, more then just a Distributor curve, Your Roadster light, Your combo is a late 60s nostalgic horsepower ,,, Like 290-320 hp, I would say 9 in 1/8 Close to 13 - 13.50s 1/4, Change gear or Change converter 3,000-3,5000 Or change compression 10-5.1 plus Then needs more cam, me in 327 .485 or & bigger , then head work , & or better flowing heads , Intake ( I can not remember witch one you used) Me If not running a Holley , I would use a Qjet . or a even Easier Fix No changes accept Add Spray ,100 hp touch of Button!!
That cam probably generates good cylinder pressures, but its a small cam with very low duration. sub-300 hp. If you need a recurve, look me up. I'm running about a week turn-around.
Correct me if I’m wrong, but that cam (including my own comp cam I just bought) has 4 degrees advance built into the cam. You find that out by subtracting the intake centerline from the lobe separation angle. your cam card says 108 Intake centerline and 112 LSA. That’s 4 degrees advanced already right?
Anyone comment on this? I'd love to have someone educated on this topic, confirm or deny. If this is the case, I'm certainly not taking the front of my engine off to add four more degrees
This is in fact the case. Now, any cam you install should really be checked when you install it to make sure of accuracy, but that Comp cam is indeed ground 4 deg advanced and should be that way when installed in straight up location on a timing set.
Got painful first and second hand experience with cam timing issues like OEM parts with keyways out of position, and even shops that "race motorcycles" totally fouling up assembly by timing marks.
Agreed. I always degreed the cams for my Cadillac powered race car. Usually within a couple degrees, but one was 12 degrees retarded. Now that would have been a sorry running deal. Redrilled the sprocket and made a new mark to get it in phase. Great cam though!
Okay, after some hacking and TIG welding, I finally have an operational timing tab on my 327 Chevy. I have the initial timing (with the vacuum advance unhooked and plugged) set at 8°. The engine definitely likes that better than 6. When I set my timing light to 32° and crank it up to 3,000 RPM, I am about 8° shy (24°). I have the stock springs in my MSD distributor and as I mentioned previously, I have a spring kit- anyone have any suggestions which ones to try first? The goal is to add 8° at 3,000 RPM.
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