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Thread: budget build questions for the advanced tuners 6825 ecm $0d bin

  1. #1
    Fuel Injected! jim_in_dorris's Avatar
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    budget build questions for the advanced tuners 6825 ecm $0d bin

    Ok, I know I am going to catch a lot of flack for this, but the budget is really tight right now. I have a low milage 283 that I can replace the cam in (the current cam is waaay to large) bolt on my rebuilt 193 heads (I hand lapped the valves) and drop it in my truck for around $200. My questions center around 2 things;

    1. if I am using the 8625 ecm, should I use the 350 knock sensor or will the 305 knock sensor work better?

    2. In the bin, I have changed the displacement to reflect the correct value, and I will be using the 61# 350 injectors (I estimate HP at around 289hp at 5000 rpm) do I need to change anything else in the bin? I know that the fuel and timing will need to be changed to get it right, just need it up and running soon, I can make data logs and change my tables once it is running.

    <edit> I realized my title got the ecm incorrect, it is an 8625 that I have a $0d bin in.
    Last edited by jim_in_dorris; 03-16-2017 at 12:26 AM.
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  2. #2
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    283 was a nice engine and very fuel efficient although it doesn't produce a ton of torque.

    Knock sensor should match bore diameter as close as possible. A 3.8 / 3800 Buick engine is probably closest at 3.800" bore. If I had to pick a smallblock sensor I would use the 350 version.

    Cranking fueling and acceleration tables are often MS pulse width and are not affected by injector constant. They could be very rich for your engine. Maybe someone who knows this mask better could address that?

  3. #3
    Super Moderator dave w's Avatar
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    The 8625 PCM requires using a 4K resistance Knock Sensor. I agree with 1project2many, a knock sensor with a near identical bore, as long as the knock sensor measures 4K +/- a very small %.

    dave w

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    Fuel Injected! jim_in_dorris's Avatar
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    Thanks guys, that's the response I was hoping for. The block has been bored 30 over so the bore is 3.9, half way between the 3.8 and 5.7 bores.
    I think the $0D mask uses injector sizing. I know the fuel will be way off, and I am fairly certain the timing will also need work, but that is okay, it isn't my daily driver.
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  5. #5
    Fuel Injected! jim_in_dorris's Avatar
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    Any thoughts on using a comp cams 12-230-2 cam. 250/260 adv. duration. 110 lsa. 432/444 lift with 1.5s, 461/474 in 1.6s. Will it be able to run at all on a stock $0D bin?
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    Comp's online cam selector doesn't show this cam for an EFI application but I think you'll be ok. It looks fairly mild. It's got less lift and duration than the Speed Pro cam in my '57 although the lobes are a little tighter. 35 deg overlap vs 64 on the Speed Pro.

    Is this something you have already, or is one for sale at a good price?

    Edit: I just started looking at cams for SBC and nearly fell off my chair! $250 for flat tappet cams??? Ouch!!
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    Fuel Injected! jim_in_dorris's Avatar
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    It's not an efi application cam, that is why I asked. It is fairly mild, with the 1.6 rockers I am at the limits of lift for the heads. I really can't afford to do to much work at the machine shop, so I limited myself to that cam. I found it at AutoZone for a really good price, but I am waiting until the first of the month to buy it. I have run a bunch of cams through Desktop dyno, and this cam seems like it produces the best numbers for the money I can afford. I am willing to look at other cams, but none of them seem to be very effective with this small a displacement and the 193 heads. I also try to get my torque in as early as possible, so a bigger overlap and looser lobs doesn't seem to work as well for a pickup.
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    I have a 350 hp 327 copy cam in my truck and that's definitely not an EFI cam. It wasn't as easy to use with the original 1983 Camaro ecm but the 7427 was easy to tune. I wonder if the EFI friendly qualities that were developed in the '80s when no one had access to tuning are still being applied to some of the cams.

    Crane makes a couple of low rpm peak cams as well. 114102 is 500 to 4000 rpm while 113971 is 800 - 4600 rpm. I've used the 114102 with excellent results under a carb in a 350 with swirl port heads. The truck had 2.73 axles and a manual trans. The combination was very strong on the highway.
    http://www.cranecams.com/uploads/cat...%20Catalog.pdf

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    Quote Originally Posted by 1project2many View Post
    I have a 350 hp 327 copy cam in my truck and that's definitely not an EFI cam. It wasn't as easy to use with the original 1983 Camaro ecm but the 7427 was easy to tune. I wonder if the EFI friendly qualities that were developed in the '80s when no one had access to tuning are still being applied to some of the cams.

    Crane makes a couple of low rpm peak cams as well. 114102 is 500 to 4000 rpm while 113971 is 800 - 4600 rpm. I've used the 114102 with excellent results under a carb in a 350 with swirl port heads. The truck had 2.73 axles and a manual trans. The combination was very strong on the highway.
    http://www.cranecams.com/uploads/cat...%20Catalog.pdf
    I have run the Stock 305 HO grind in several TBI and TPI setups. Has a smooth idle with plenty of vacuum and makes good mid-top range TQ and HP.

    Its like 202/207@ .050, .415/.430" lift cut on a 114 LSA and 114 ICL.

    I have also used several of the 204/214 @ .050 grinds in them. With .423/.446" lift it would be a stretch to run a 1.6:1 rocker with stock TBI springs. Woth its 112 LSA and 4 built-in advamce it builds more low RPM torque but falls off on the top end more quickly.

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    I am a little off on the lift of the HO cam. The specs I have are for the roller version used in the 87+ LB9/L98/9C1 engines.

    https://m.summitracing.com/parts/mel-ccs-37

    https://m.summitracing.com/parts/mel-cl-mtc-1

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    Fuel Injected! jim_in_dorris's Avatar
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    That second melling cam makes a lot of ponies on small displacement. I wish the torque was stronger. I really appreciate the responses. I have checked out about 10 cams so far, all of which are not bad cams, but for the $ i have to spend, the comp cam still looks good for what I want. I need to go buy a set of small bore split ball gauges and measure my valve guides, I think I may have to spring for some more machine work. All of the valve stems I have measured (both intake and exhaust from 2 different 350's) are .334-.335 diameter, which is smaller than what I thought they were supposed to be, but having identical sizes between the two heads from different motors makes me wonder if the stock valves were just that size. I have 1 head in the shop right now getting surfaced, it was a little low between the 2 middle cylinders. My son and I took the 882 heads off the 283 Sunday, and the motor looks clean, still has some of the cross-hatch from when it was built. Going to redo the front and rear main seals, and maybe peek at a bearing before I start putting it back together.
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    Just go turbo. Even a mild cam makes power with forced induction.

  13. #13
    Super Moderator dave w's Avatar
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    Back in the late 80's I helped build a budget / non-fuel injected 283. For heads, we used early 80's 305 heads with 1.84" intake and 1.50" exhaust valves. The 283 had 1.72" intake valves and 1.50" exhaust valves. The 305 heads were ready for unleaded fuel, which saved money not having to install harden exhaust valve seats into the 283 heads. The early 80's 305 heads with 1.84" intake valves had a similar combustion chamber cc size similar to the original 283 heads (about 58cc's if I'm remembering correctly). We used the factory 4 barrel intake and quadrajet carburetor from the early 80's 305. The camshaft was a re-ground "Clone" of the Competition Cam 252 torque cam of the late 80's. We also upgraded the ignition system to the early 80's 305 4 Pin HEI distributor. The overall outcome was surprisingly good, the 305 modernized 283 able to hold it's own up against an Impala 327 of the mid 1960's.

    dave w

  14. #14
    Fuel Injected! jim_in_dorris's Avatar
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    That's nice to know, I am only building this to last until I can get back in the black. Starting next month, I will have more work and that should ease the budget somewhat. Fixing my wife's Blazer last summer and fall kind of wiped out my budget for fixing my truck, so this is just stop gap. I bought a set of small bore gauges tonight, so I can check the guides. I hope that I don't have to spring for too much work on the heads, it will delay getting it back together. Oh well, so goes life in the country.
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    Fuel Injected! jim_in_dorris's Avatar
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    Well, I just can't seem to win. Took the better of the 2 193 heads in to get milled. Turns out it is cracked, no wonder the truck ran crappy. Now I just went over budget again. Do I just put the good set of low compression 882 heads on that I already own, and find an intake manifold? How hard is it to slot the center bolt holes on the stock tbi manifold to use the 882 heads? I will disassemble the 882 heads, and put new valve seals on, hand lap the valves and call it good. Will the 882 heads allow the .474 exhaust lift?
    Square body stepsides forever!!!

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