mat in tn Posted August 6 Share Posted August 6 When I got the truck there was a camshaft in a new box in the back. I cant tell if it was the old original one, or the one he wanted to put in. How can I determine what cam shaft is in the engine now? mystery camshafts can be a real pain to discern. measuring the cam in the box might help at least answer some questions. like what is supposed to be in the box. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted August 6 Share Posted August 6 When I got the truck there was a camshaft in a new box in the back. I cant tell if it was the old original one, or the one he wanted to put in. How can I determine what cam shaft is in the engine now? If it was the one that came in the truck it would be burnished on the entirety of the lobes, and look used.... Link to comment Share on other sites More sharing options...
mat in tn Posted August 7 Share Posted August 7 If it was the one that came in the truck it would be burnished on the entirety of the lobes, and look used.... absolutely. but measure it to know Link to comment Share on other sites More sharing options...
asdfghjkllkjhgfdsa Posted August 7 Author Share Posted August 7 Okay Im starting to piece together what the previous owner did/wanted. He locked out the distributor because he put a large cam in and was looking to make a track vehicle. Thats why when I set timing to something the engine is happy with it idles at 1000+ rpm, and has nearly 36 degrees of advance. Plus i need the idle set screws almost 5-6 turns out to idle without stalling. My question is, I need a work truck, something reliable at low speeds with good torque and reliable start. If he put a large cam in it, can I ever get back that good low end power and reliable start? I dont have a way to remove the engine and replace the cam, so it would all have to be done in my front driveway, whatever that is. Some people have mentioned an MSD system to retard the timing during start. Can a MSD system like this be hooked up to a DUI HEI distributor? The other option was modding some type of pin control in the distributor. And then am I only ever going to have power at 3000rpm and up? I really love the truck, and love the idea of a no computer, simple reliable, 300 I6, but if I need a shop to make it so then I probably just need to sell it and get something else. Link to comment Share on other sites More sharing options...
mat in tn Posted August 7 Share Posted August 7 Okay Im starting to piece together what the previous owner did/wanted. He locked out the distributor because he put a large cam in and was looking to make a track vehicle. Thats why when I set timing to something the engine is happy with it idles at 1000+ rpm, and has nearly 36 degrees of advance. Plus i need the idle set screws almost 5-6 turns out to idle without stalling. My question is, I need a work truck, something reliable at low speeds with good torque and reliable start. If he put a large cam in it, can I ever get back that good low end power and reliable start? I dont have a way to remove the engine and replace the cam, so it would all have to be done in my front driveway, whatever that is. Some people have mentioned an MSD system to retard the timing during start. Can a MSD system like this be hooked up to a DUI HEI distributor? The other option was modding some type of pin control in the distributor. And then am I only ever going to have power at 3000rpm and up? I really love the truck, and love the idea of a no computer, simple reliable, 300 I6, but if I need a shop to make it so then I probably just need to sell it and get something else. it's also very possible that the previous owner did not get the results expected and gave up on it. what carburetor is on it? I'm wondering if you might not just need another carb or a rebuild. you say that you have a cam in a box, is it possible that the info is still in or on the box saying what the cam is? that may help . Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted August 7 Share Posted August 7 Okay Im starting to piece together what the previous owner did/wanted. He locked out the distributor because he put a large cam in and was looking to make a track vehicle. Thats why when I set timing to something the engine is happy with it idles at 1000+ rpm, and has nearly 36 degrees of advance. Plus i need the idle set screws almost 5-6 turns out to idle without stalling. My question is, I need a work truck, something reliable at low speeds with good torque and reliable start. If he put a large cam in it, can I ever get back that good low end power and reliable start? I dont have a way to remove the engine and replace the cam, so it would all have to be done in my front driveway, whatever that is. Some people have mentioned an MSD system to retard the timing during start. Can a MSD system like this be hooked up to a DUI HEI distributor? The other option was modding some type of pin control in the distributor. And then am I only ever going to have power at 3000rpm and up? I really love the truck, and love the idea of a no computer, simple reliable, 300 I6, but if I need a shop to make it so then I probably just need to sell it and get something else. In the 3rd post I suggested that you get a 5 pin GM module and wire H through a relay to ground and have it triggered by the (I) post on the starter relay so it retards 10° while cranking If you have a cam with a load of overlap it's never going to pull from idle. You're going to have to wind it up to where there's enough dynamic compression to make power. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted August 7 Share Posted August 7 it's also very possible that the previous owner did not get the results expected and gave up on it. what carburetor is on it? I'm wondering if you might not just need another carb or a rebuild. you say that you have a cam in a box, is it possible that the info is still in or on the box saying what the cam is? that may help . Matt, He stated 2150 in the first paragraph of the thread. I asked which manifold, but still don't know. Link to comment Share on other sites More sharing options...
mat in tn Posted August 8 Share Posted August 8 Matt, He stated 2150 in the first paragraph of the thread. I asked which manifold, but still don't know. I find it rather odd that anyone dug deep enough to do a radical cam and still put a 2150 on top. I'm hoping to get cam specs if possible. my bigger concern is how it was rebuilt more than what with. Link to comment Share on other sites More sharing options...
asdfghjkllkjhgfdsa Posted August 8 Author Share Posted August 8 I find it rather odd that anyone dug deep enough to do a radical cam and still put a 2150 on top. I'm hoping to get cam specs if possible. my bigger concern is how it was rebuilt more than what with. The manifold is an Offenhauser dual port 240/300 cfm. I have a phenolic spacer/2-4 port adapter that is open, so the dual port thing shouldn't much matter. The box that has the cam in it says comp cam part# 66-248-4, grind# f66 268h-10, gross valve lift .456 duration at .006 tappet lift 268 valve timing open @.006 int 28, btdc 60 exh 68. (The cam looks new too me, so it might have never been installed, but it could be the old one too) The original carburetor was a Holley 4160. I replaced it with a Motocraft 2150. I have the same stumble off idle issue with both carburetors, which is what led me to thinking this is a timing issue. Ever since I cracked open the distributor and unstuck the centrifugal weights, I have not been able to get the timing back down under 32 degrees without killing the engine. It seems happy around 36-40 degrees and will idle @800rpm (dropping to 600 when in gear) and an idle vacuum of 20. Tried turning over the engine before kicking the start and that seems to help with the hard starting. Thanks for that tip! Anyways I took it out for another drive after setting it to sound decent and somewhat steady (still fluctuates a bit). Good acceleration, good feel for about 2 minutes (like always) and then it starts to stumble when coming off an idle. This stumble gets worse when you push the accelerator, and to keep from killing it you have to completely take your foot off. It also progressively gets worse doing this off idle stumble more and more over the course of minutes. Finally the stumble will get to the point it kills the engine entirely. You then have to wait a couple minutes to restart the engine. I also noticed that a small oil leak at what I think is the rear seal, seems to get worse after driving it like this. Maybe the engine oil pressure is going up above a threshold when its running poorly, because the leak doesn't seem to happen all the time. Link to comment Share on other sites More sharing options...
asdfghjkllkjhgfdsa Posted August 8 Author Share Posted August 8 This is the DUI HEI Distributor opened up. Looks fine to me, but I'm open to any input Link to comment Share on other sites More sharing options...
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