Well I ported my exhaust manifolds to match my gasket. The manifolds have big holes so I decided by the way the port on the manifold was made it would be best to off set it to the right. I thought about how that would set the port on my cylinder head (cause i had not ported my heads yet) but figured it would be ok. So i ported one of my ports on the cylinder head to match the manifold but took a little to much off the side on the top part of the port. To correct this I had to take more off metal off of the side the port was already leaning to. I took pictures and now I am looking at the pics and see that the port is really leaning to one side will this cause a problem? I attached a file with the picture in it
oh by the way here is a pic of the manifold its hard to tell but the ports do lean to one side however I will now have to make them lean even more now so they match the cylinder head port any comments or thoughts?
I dont see any problem but I am no expert. It looks like you have lots of metal left to work with so I wouldnt worry to much about it. Since you are running the stock manifolds you should be in good shape, they are forgiving. Why not use headers? You will see more benefit from them than what you are doing, although they can be a pain they are worth it if you are looking for more performance. Looking good!
well i dont think headers are going to be as much of an advantage as everyone makes them out to be. Right now I am concerned about getting a strong bottom end, a good intake combination and some good heads to match. The problem I see with headers is the crearance, smog legality, extra underhood heat and for how much of a gain. Now I know as I port my heads, the manifold must not be smaller or turbulance will be created, which will cause a lack of scavanging from the cylinders. I also don't want to over scavange which is why i am going with the 1.55 exhaust valve and trying to keep the exhaust port size down. I also believe there are negative effects when a smaller port is dumping into a much bigger tube.
David; Ports do not seem to be to bad in the pics.Remember the most beneficial porting with a minimum of increasing the port volume is around the bowl area.And don't forget to remove(the bump). Herb
LOL you shouldnt have noticed the bumps cause they are not there. What you are seeing is the valve guide. I cut the bumps out but left the full valve guide because upon reading articles people found that removing them is little benefit. What do you guys think about leaving the guides.
I left my valve guides but cleaned up around them and smoothed them out a little. Havent run the engine yet so I have no idea how it will help....heck, probably wouldnt know even if the engine was running! I understand about the headers. I want every ounce of power I can get out of mine so I am going with headers. I won't get rid of my stock manifolds though...may need them later.
Ya the headers would be great and I may end up realizing that I actually do need them. Im learning. You are right that it is an advantage to have them, plus they make the engine look meaner. Just like the discussion I was having about the gears earlier on this board, I decided to go with them and see what happens. Then change them if needed.
David look at the difference between your stock iron manifold and shorty headers, there is no comparison. For good low end torque, a cam change would be in order using a cam known as an RV cam. These cams are less than $90 new and will do more with some supporting parts than your work with the stock setup will yield. If you don't have floor shift then your stuck with the iron headers but the cam will still give good results for the money and effort. Grinding the bumps out is fine but the gases are still being impedded by the stock iron headers so the results are less than they should be. Basicaly the stock exhaust is fine until you start using the engine at much higher rpm were the gas flow starts to become limited from flow restrictions. Under 2500 rpm, after market exhaust or other improvement won't be felt because the system is still large enough to handle it by original factory design. Just a different view of what your doing. Good luck.
I will say that headers do give the engine a much crisper throttle response, especially when combined with a high-flowing exhaust system.
Yes I know a cam change would be appropriate. That is why I have an '87 (e7te) roller block prepped. I also had my rods shot peened and reconditioned with arp bolts installed. The crank was ground so that it would fit in the '87 block ( i had to have the lip right before the rear main seal removed) I also had it turned .010. I am running the single pattern E303 roller cam ( 282 duration with a .498 valve lift with 1.6 rocker arms) with new lifters, pushrods, and of course a true double roller timing chain. Also I know for a fact the exhaust manifolds are fine for high rpm because the 289 hi performance motors still used the stock manifolds similar to the ones i have. Look at pictures that show the manifolds I have ( I can send u more pics) and the 289's. They actually called those block hugging cast iron headers in the '60s. Those motors peaked in hp at 6000 rpm. Plus look at what comes equiped on the 4.6 mustang cobras they're disgusting. Those motors peak at 5,800 rpm. Also I am not running those manifolds completely stock. I spent about a day opening them up. I agree headers will give an advantage in mainly torque with some hp, but how much? One thing to note is that those heads you are looking at are '75 351w. Now alot of literature will tell u that the 75s had the larger chambers and smaller ports. Thats not true. the '75s have the same size combustion chambers as the 70s 351w(we cced them and foud them to be close to 60.4) and the ports are the same size as the 70s heads. They are also much larger than the 302 and 289 ports. In these heads I am going to install 1.94/1.55 undercut ferrea valves. For an intake manifold I am using the performer series edelbrock manifold (ported to match the larger intake ports on the heads), topped off with a holley 4180c with the secondary jet kit from summit. The valve springs are the double valve springs crane cams recommends for this cam (crane actually makes the fms cams for ford). The rocker arms will be the roller tip folcron type, which is not the full roller. This motor is not a stock setup.
