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Fair enough. I never had a stand nor would I ever own a carburetor if you gave me one so I'd have to hook up the EFI.
Ran nothing but carbs for years when we raced. My '85 was actually my introduction to fuel injection. After an initial (and still ongoing) learning curve, I would have to agree: no more carbs for me. I would love to setup my run stand with an ECM and harness, but that probably isn't going to happen.
Another question... a friend of mine who fancies himself an engine builder said I am going to have low vacuum issues with this engine. Huh ? He didn't elaborate. It is 10:1 compression and I plan on running the Mini Ram. Personally, I think he is full of it. Any thoughts on this issue ??????
Another question... a friend of mine who fancies himself an engine builder said I am going to have low vacuum issues with this engine. Huh ? He didn't elaborate. It is 10:1 compression and I plan on running the Mini Ram. Personally, I think he is full of it. Any thoughts on this issue ??????
Well the vacuum will be lower then stock at idle but I do not think it will be an issue that will cause problems. I believe you will still have enough vacuum to run the power brakes as expected. Other then that the vacuum will not be an issue. (If you do have power brake issues you can always add in an extra vacuum canister.) (I am assuming the cam is the XE274H)
Another question... a friend of mine who fancies himself an engine builder said I am going to have low vacuum issues with this engine. Huh ? He didn't elaborate. It is 10:1 compression and I plan on running the Mini Ram. Personally, I think he is full of it. Any thoughts on this issue ??????
This is going to more driven by the cam you're going to use, specifically the degree of overlap, and lobe seperation. Given a cam that will have lots of overlap and lope you will encounter some vacuum issues, but running a mild cam, you shouldnt have any problems.
Well the vacuum will be lower then stock at idle but I do not think it will be an issue that will cause problems. I believe you will still have enough vacuum to run the power brakes as expected. Other then that the vacuum will not be an issue. (If you do have power brake issues you can always add in an extra vacuum canister.) (I am assuming the cam is the XE274H)
That's the one ! Side question, any thoughts on crankcase evacuation ? I have a billet filtered catch can somewhere in my parts.
That's the one ! Side question, any thoughts on crankcase evacuation ? I have a billet filtered catch can somewhere in my parts.
I would still run a PCV valve and breather to the air cleaner. It keeps the engine much cleaner by since it pulls away blowby from the rings and keeps the extra pressure from forcing oil out through the gaskets.
I have attached a dyno chart that I found from Comp cams on a 355, what is interesting is the idle vacuum at 800 RPM is 11", you will be fine with your vacuum on a 383.
I have attached a dyno chart that I found from Comp cams on a 355, what is interesting is the idle vacuum at 800 RPM is 11", you will be fine with your vacuum on a 383.
Thanks, I can scratch that off my list !
I appreciate the info and help. I may not be able to wait until winter to swap this thing in ! Still need to save the coin for the Mini Ram and new converter.
I would still run a PCV valve and breather to the air cleaner. It keeps the engine much cleaner by
since it pulls away blowby from the rings and keeps the extra pressure from forcing oil out through the gaskets.
True but what of the inside? Out of sight, out of mind maybe? Where do you think the gunk in the IAC area comes from? What was coating the Air Intake Sensor in my intake? The oil mist will coat sensors. On my Powerstroke, taking that out of the equation did save a lot of oil being introduced into the intake and intercooler track.
If you have that much pressure, is the engine still staying together much longer? Once I had that kind of pressure, the thing was on the way out most of the time.
True but what of the inside? Out of sight, out of mind maybe? Where do you think the gunk in the IAC area comes from? What was coating the Air Intake Sensor in my intake? The oil mist will coat sensors. On my Powerstroke, taking that out of the equation did save a lot of oil being introduced into the intake and intercooler track.
If you have that much pressure, is the engine still staying together much longer? Once I had that kind of pressure, the thing was on the way out most of the time.
What I am suggesting is what is has been done from the factory since the 1960's. Sure if the engine is shot this will not fix anything, but as long as the engine is in good shape the PCV will help keep it clean with no negative consiquences. (The breather pulls the air from ahead of the throttle and the PCV dumps in behind the throttle. So you really only see oil vapors ahead of the throttle body (IAC) when you are at WOT and there is no engine vacuum to draw vapors through the PCV)
What I am suggesting is what is has been done from the factory since the 1960's. Sure if the engine is shot this will not fix anything, but as long as the engine is in good shape the PCV will help keep it clean with no negative consiquences. (The breather pulls the air from ahead of the throttle and the PCV dumps in behind the throttle. So you really only see oil vapors ahead of the throttle body (IAC) when you are at WOT and there is no engine vacuum to draw vapors through the PCV)
Tearing my IAC off and looking inside with a flashlight, I have seen that my temp sensor and inside the intake has a film of oil. Why would I prefer that to having it outside?
Tearing my IAC off and looking inside with a flashlight, I have seen that my temp sensor and inside the intake has a film of oil. Why would I prefer that to having it outside?
You can do whatever you want but if you do external breather (as mentioned in post 26) the crankcase pressure creates a slight positive pressure in the crank that allows oil vapors to slowly squeeze out through the gaskets and the engine eventually looks like an oily mess. (The breathers on the valve covers also make a mess) If you run a PCV this does not happen or happens at a much slower rate.
You can do whatever you want but if you do external breather (as mentioned in post 26) the crankcase pressure creates a slight positive pressure in the crank that allows oil vapors to slowly squeeze out through the gaskets and the engine eventually looks like an oily mess. (The breathers on the valve covers also make a mess) If you run a PCV this does not happen or happens at a much slower rate.
Agreed that it is a possibility for the catch can or whatever it is you put in line but venting to atmosphere might make it messy but can be washed off, I would think and keeps the inside cleaner. Beyond that, what other drawbacks that a degreaser won't fix?
Agreed that it is a possibility for the catch can or whatever it is you put in line but venting to atmosphere might make it messy but can be washed off, I would think and keeps the inside cleaner. Beyond that, what other drawbacks that a degreaser won't fix?
Seems to me that when I had my catch can system set up on a 350 years ago, I just plumbed it in line so vapors/oil went through the catch can and then back to the TB in this case. You can remove the filter on my catch can and cap it, so it becomes a closed system.
EDIT: i agree with keeping the TB & intake as clean as possible: I removed and cleaned the TB on that Trans AM I just picked up. The intake is beyond nasty from build up !!!!
Seems to me that when I had my catch can system set up on a 350 years ago, I just plumbed it in line so vapors/oil went through the catch can and then back to the TB in this case. You can remove the filter on my catch can and cap it, so it becomes a closed system.
EDIT: i agree with keeping the TB & intake as clean as possible: I removed and cleaned the TB on that Trans AM I just picked up. The intake is beyond nasty from build up !!!!
Kinda why I think that a can of brake cleaner on the valve covers goes a long way.
Ok, here's the deal. Number one I am NOT an engine builder and don't pretend to be, so I need the gurus opinion(s).
I picked up a 383 pretty cheap (I think) from a local guy, that I plan to eventually go into my 1985. I don't plan on racing it, just want a little more go on the street.
Finally tracked down the shop (reputable local builder) where most of the work was done and this is what I've got:
1987 block bored .30 over.
Comp Cam, gross valve lift .490, duration @ .050,230/236
Dart Iron Eagle SS heads,67cc combustion chambers
Eagle cast crank #103523750571
Scat forged rods
Speed Pro H860CP30 pistons
Hastings ring set
Comp Cam guides & springs
Melling Hi volume, Hi pressure pump
Engine Pro 1.5 roller rockers
Balanced
Came with an Edelbrock 7501 Air Gap intake and Quick Fuel SS780VS carb. My plans are to do the initial break in using the carbed setup on my run stand.
The builder estimated 425 hp at the crank and about 330 at the wheels. Does this sound about right or not ? It doesn't seem like a "wild" setup to me.
Obviously I will need a new tune so I am planning to upgrade the ECM and if funds allow, a Mini Ram setup.
Any thoughts/opinions are welcome !
You didn't say what the comp. ratio is for those pistons and heads,so I looked it up for you.With 67 cc heads it is 10-1.You wondered about the horsepower estimate being too little from the builder.I can tell you that I have almost the exact same set up in my 87 except for a bigger cam in mine.same cc heads,same cfm carb,similar comp. ratio, etc. All mine is balanced and heads flowed and matched with the intake and exhaust ports.You didn't say if it's balanced or heads ported and matched.Might be something to ask the builder.I'll assume that none of that has been done for now.Only way to really tell is to have it dynoed.Mine was dynoed at 461 to the wheels which translates to about 540 at the crank.Approx. 15% loss through the drivetrain.As for going to a F.I. setup you would be much better off to get a custom ecm made than getting a chip made for the stock ecm.It is only an educated guess at best even for the sharpest ecm chip maker in my opinion.And if you ever change anything like injectors,headers,timing,have head work done etc. you will have to have the chip re programed.A company called dynamic EFI can build you a custom ecm for a very reasonable price and then you can hook up a lap top to it and make any tuning changes you want at any time.It's going to be expensive to go to a good EFI set up and custom ECM.I stuck with a carb because of expense and ease of tuning.I'm an old school guy and am good with carbs,and in my (and in quite a few eng. builders) opinions you can make as much horsepower with a carb.EFI to many is easier to tune and yes it is more efficient to some extent which many will say translates to more H.P.The TPIS miniram is the best set up in my opinion for any steet strip car.If you keep the the carb you are going to have to put a hood scoop on because after putting on the air cleaner it's going to be too high.I went with the greenwood one.There is a guy in florida that bought the molds and is very helpful about installation questions.As for a converter I have a 3600 stall in mine,but I drag race the car also.If I were you I'd go with a 2600-3000,leaning towards the 3000 one.You will want to have wired in a toggle switch to be able to lock up your converter when in overdrive otherwise you will be over working the converter too hard and getting the fluid too hot.Very easy to do,just google it.Anything else you need to know feel free to respond directly to me.
I would still run a PCV valve and breather to the air cleaner. It keeps the engine much cleaner by since it pulls away blowby from the rings and keeps the extra pressure from forcing oil out through the gaskets.
As I previously stated I have a much bigger cam and ran into brake vacuum issues and had to put a vacuum storage canister on mine.You can test yours by revving it up in second gear to about 4000 rpm and jamming the brakes on hard.Please do it in an empty parking lot or somewhere with plenty of room in case you spin out or it doesn't stop.If your brake pedal gets hard and it feels like you loose power brakes that will tell you if the sudden drop in vacuum is going to be too much.Definitely go with wih a pcv or you will blow oil out the breather at higher rpm's,as I learned the hard way.You should also go with 1 3/4 inch headers so it can breathe along with 3 inch true duals with an x pipe.Don't cheap out on the headers,get a good brand ceramic coated set.Hookers are the best in my opinion,but not cheap.You can get a 3" true dual exhaust system with clamps included for $330 from melrose corvettes.You don't need 3" from the last pipe into the mufflers.By that time the exhaust is cooled down enough and scavenged through the x pipe to make max HP.I like the borla's for mufflers.They make the best sound and HP from what I've seen on dyno results.Hope this helps,good luck.
I'm a little late to the show. I didn't see if the cam is a hydraulic roller or a flat tappet. The lift seems a little underwhelming for a roller cam. If it is a flat tappet, consider going with a roller. You'll be gaining hp and torque. If it is a roller, get more lift. One last note, I am not a great fan of Comp Cams. They do a great job marketing, but there are better cam manufacturers out there.
You didn't say what the comp. ratio is for those pistons and heads,so I looked it up for you.With 67 cc heads it is 10-1.You wondered about the horsepower estimate being too little from the builder.I can tell you that I have almost the exact same set up in my 87 except for a bigger cam in mine.same cc heads,same cfm carb,similar comp. ratio, etc. All mine is balanced and heads flowed and matched with the intake and exhaust ports.You didn't say if it's balanced or heads ported and matched.Might be something to ask the builder.I'll assume that none of that has been done for now.Only way to really tell is to have it dynoed.Mine was dynoed at 461 to the wheels which translates to about 540 at the crank.Approx. 15% loss through the drivetrain.As for going to a F.I. setup you would be much better off to get a custom ecm made than getting a chip made for the stock ecm.It is only an educated guess at best even for the sharpest ecm chip maker in my opinion.And if you ever change anything like injectors,headers,timing,have head work done etc. you will have to have the chip re programed.A company called dynamic EFI can build you a custom ecm for a very reasonable price and then you can hook up a lap top to it and make any tuning changes you want at any time.It's going to be expensive to go to a good EFI set up and custom ECM.I stuck with a carb because of expense and ease of tuning.I'm an old school guy and am good with carbs,and in my (and in quite a few eng. builders) opinions you can make as much horsepower with a carb.EFI to many is easier to tune and yes it is more efficient to some extent which many will say translates to more H.P.The TPIS miniram is the best set up in my opinion for any steet strip car.If you keep the the carb you are going to have to put a hood scoop on because after putting on the air cleaner it's going to be too high.I went with the greenwood one.There is a guy in florida that bought the molds and is very helpful about installation questions.As for a converter I have a 3600 stall in mine,but I drag race the car also.If I were you I'd go with a 2600-3000,leaning towards the 3000 one.You will want to have wired in a toggle switch to be able to lock up your converter when in overdrive otherwise you will be over working the converter too hard and getting the fluid too hot.Very easy to do,just google it.Anything else you need to know feel free to respond directly to me.
Yeah, sorry, 10:1 compression. I do know that it was balanced, but I would have to ask about the other work. Thanks for the stall info. As for the ECM I thought about a later year computer with a custom tune. Damn, I hope you are right about the horsepower ! What are running for a tranny and rear end behind all those ponies ?
I'm a little late to the show. I didn't see if the cam is a hydraulic roller or a flat tappet. The lift seems a little underwhelming for a roller cam. If it is a flat tappet, consider going with a roller. You'll be gaining hp and torque. If it is a roller, get more lift. One last note, I am not a great fan of Comp Cams. They do a great job marketing, but there are better cam manufacturers out there.
Flat tappet cam. I bought the engine as is: still virgin, never been fired. I have heard all the horror stories about Comp: hope I am one of the luckier ones.
03-29-2017, 07:00 AM
What are running for a tranny and rear end behind all those ponies ?