pi head swap cam or not
- Thread starter Ryan441
- Start date
make sure that the guy has experience porting 2v heads. If he doesnt, I wouldnt let them port them unless you gives you exact details on what he is going to do.
As far as numbers, 265-285 is normal with headers and a tune. My times and numbers are in my sig, but that is untuned and with stock exhaust manifolds. Its a good time to do the cams whiles the heads are off, but its not necessary. Eitherway, it will be fun.
As far as numbers, 265-285 is normal with headers and a tune. My times and numbers are in my sig, but that is untuned and with stock exhaust manifolds. Its a good time to do the cams whiles the heads are off, but its not necessary. Eitherway, it will be fun.
You can find PI cams cheap. I'd go ahead and do the whole thing to get the full benefit. You can also find aftermarket cams used if you want to go that route. I paid 325 for a set of Comp 262's with 6000 miles on them. I've added another 60K since install with zero issues.
blackfang
Founding Member
If you port them, you might as well go aftermarket cams. The PI cams and PI Intake make up the majority of the hp gains with the heads roughly 5-10. You can also port the NPI heads you can make more power than a PI headswap. If you port the PI heads, you would be better off doing aftermarket cams.
blackfang
Founding Member
Ported PI Heads vs. Ported Non-PI heads is hardly a difference to brag about
The heads are not a restriction as much as you people make them out to be. The Cams and Intake are. After porting, the NPI's are as equal, if not better N/A than PI's. With a little work and reshaping of the intake ports, they will flow much better than the PI counterparts, since the PI's don’t have as much meat in them to port. The exhaust ports on the PI heads is much better stock than the NPI's, but with dilligent work, NPI’s can flow almost as well as ported PI's. the NPi's have a quench pad that allow for a faster and hotter burn in the chambers, which we all know is key to N/A power success.
Port the PI heads w/PI cams= chances are you may have to go with after market cams being you won't make as good results with the stock PI cams.
not true. Many of the old school guys ran ported PI head cars with stock cams before aftermarket cams were available, and many were in the mid to low 12's na with higher trap speeds than just PI swapped cars. Porting the heads does not require you to use aftermarket cams, to see gains over stock pi heads, but it does help
blackfang
Founding Member
I can also counter that. Many were running low 12's with NPI heads as well. I never said you had to use after market cams. However, I believe I said you may not make as good results with a PI Cam than an after market. To take advantage of the increase ability to push air and get the most hp and best results it would be wise to use after market cams over PI ones.
There are several ported NPI engines making just as much if not more power with PI cams and PI Intake. Some have gotten 250-260 rwhp with them. I am simply stating that you can get away with just the PI Cams and PI Intake and port the NPI heads and still make more HP than if you just went with a PI headswap.
I agree with most of what you are saying but you fail to mention the power gained by going from 8.5 c/r to about 10.5:1 with the PI head swap. I have to run 91-93 octane and I know a higher compression means more power.
I used to have a Excel spreadsheet with about 25 headswapped cars from StangNet & Corral. I had the mods listed and HP & TQ dyno results. From what I saw, when you port PI heads vs. not porting them on a headswap car using the PI cams does not result in any measurable power gains. My heads were P&P and I was not getting much more than similar headswaps with no P&P.
I agree with ya on that. I just thought you meant you needed to run aftermarket cams if you had the heads ported
blackfang
Founding Member
I wouldn't pay 300+ for 5-10 hp just all for a bump in c/r. I rather spend that money I saved and port the heads and get twice as much hp.
Na
You need to reread what I posted. I have been there and done that with the heads. Set them side by side and had a look. Did a couple PI Headswaps myself.
I am talking about both being ported, there is hardly a difference in flow.
blackfang
Founding Member
Im definetly not saying that. The PI heads will give you increased compression, and you get the PI cams and intake. Porting 2v heads run anywhere from 400-800 bucks, even with a good hook up. Then, you will need PI cams, or aftermarket cams with the ported NPI heads, because the 96-98 NPI cams suck and wont work well with the ported heads. More money. Then you will need new valvesprings, etc if you go with aftermarket cams, and you wont have the increased compression, which means less power.
Many of the 96-98 cars that just do the PI cam/intake swap see great gains, which I think thats what blackfang was saying. But when you start to factor in the labor/porting cost of NPI heads, its not worth it to me. Personally, Ive done 2 headswaps on my own vehicles, so I know from personal experience its great. If your not doing the labor, you might as well just go with the complete PI swap with used heads and get all the benefits. Why spend the more money on porting NPI heads(bc you have to pay for the labor of taking them off and putting them back on, and having the month or so downtown on your car while the heads are ported?)The labor for the headswap is only a couple hundred more than the just the cam and intake swap, but then you havet the benefit of increased compression and better heads, plus you dont have to buy new cams for the NPI heads
Basically what Im saying is going with just a PI cam/intake swap IS worth it, but when you start paying for labor/porting to take the stock NPI heads off and having them ported, it doesnt make smart financial sense bc then you need new cams. Its cheaper just to do the PI head swap
After this post you guys who have done swaps just post up your route and numbers. Did you do a full PI swap or cam only or a port and polish on NPI's/PI's? Whatever your process.
I have Comp 262's with the PI intake swap with stock NPI heads. My tune is a bit conservative due to the miles on my engine but I put down 230HP and 273TQ on a Mustang Dyno. The Dynojet numbers would be a bit higher. At the track I knocked off 7/10ths and added 6MPH. Before the cams/intake I ran 14.7's at 94. After the intake swap and cams (tuned) I was at 14.0 at 100...my best numbers were 13.8 at 103 with DR's. If I would get some more seat time and drop my 60 foot I could probably drop my ET by a 10th or 2.
If you have an NPI car my opinion, and only my opinion, is the complete headswap is a waste if you can find a good aftermarket cam for a good price. My numbers are only 5-7 HP off a full headswap (Dynojet numbers) and I spent $700-800 less just on parts.
Also if you are thinking a complete swap the expense may outweigh the HP gain if you take it to a shop. Instead of a HS on an NPI car or even P&P heads and cams on a PI car I'd slap a blower on way before I even thought about a headswaps, P&P's or cams.
I have Comp 262's with the PI intake swap with stock NPI heads. My tune is a bit conservative due to the miles on my engine but I put down 230HP and 273TQ on a Mustang Dyno. The Dynojet numbers would be a bit higher. At the track I knocked off 7/10ths and added 6MPH. Before the cams/intake I ran 14.7's at 94. After the intake swap and cams (tuned) I was at 14.0 at 100...my best numbers were 13.8 at 103 with DR's. If I would get some more seat time and drop my 60 foot I could probably drop my ET by a 10th or 2.
If you have an NPI car my opinion, and only my opinion, is the complete headswap is a waste if you can find a good aftermarket cam for a good price. My numbers are only 5-7 HP off a full headswap (Dynojet numbers) and I spent $700-800 less just on parts.
Also if you are thinking a complete swap the expense may outweigh the HP gain if you take it to a shop. Instead of a HS on an NPI car or even P&P heads and cams on a PI car I'd slap a blower on way before I even thought about a headswaps, P&P's or cams.
depends how much power you want. Its just cost effective to do it while the car is apart, that way you dont have to spend money again to do the cams later. Also, make sure you throw a set of LT headers on the car while the heads are off.
Like stated earlier, the parts run around 500 bucks if you buy smart. If your going to spend the money on labor to instal the cams, intake, you might as well go ahead and have better heads, and increased compression and do the whole swap.
Like stated earlier, the parts run around 500 bucks if you buy smart. If your going to spend the money on labor to instal the cams, intake, you might as well go ahead and have better heads, and increased compression and do the whole swap.
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