I have a 96 dohc engine that i am rebuilding and have about $2000 left for the engine. 85k Motor originally came from a 96 lincoln and already have the upper and lower intakes for it. I would like to make 450 - 500 hp on what is considered a smog legal daily driver in nj.
I can get the heads ported for about 700-$800
I can get forged internals with close to stock compression (ie forced induction later) for $1000
or
a forged stroker kit for close to $1800.
cams are another $600-$700
(slightly over budget any way you cut it but hey)
I was wondering how much of a benefit porting the heads would be - actually if it would be worth it. If I get the heads ported and the low compression forged internals, I could a a s/c down the road (does anybody make a twin screw or even a roots s/c or is a novi pretty much it?) How much benefit would porting be with forced induction... or with NO2... or with a stroker even? I belive the combustion chamber is enlarged and modified slightly during porting, so that would drop the compression a bit, but I am presuming the increased flow would make up for it.
Does anybody have any experience with porting DOHC heads and power gains?
Stock CR is 9.8:1 (on the B head cobra motor anyways), so you may want to bring that down a bit for FI. I would definetly go with forged internals for the power levels your anticipating. The stock rods and pistons wouldn't hold up very long under those power levels. The port and polish should work pretty good with FI, I wouldn't bother doing the stroker kit. Kenne Bell makes a non-IC 6 psi kit for the 96-98 cobra, although I'm not sure that will give you the power levels your seeking. It might be worth trying to find some 99-01 tumble port heads, or even 03-04 cobra heads if you want to go with a roots or twin screw blower.
Port them while you can. But you should try to decide what route you want to go, NA, blown or the bottle. The 3 has different things to be done to maximize the output. It'd be easier to do this now than down the road.
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yea, i was looking for some tumble port head, but the cost is the limiting factor for me. If I upgraded the heads, I would also need the intake - or sc which is more $$. Are the newer heads noticably improved over the 96-98 heads - like the PI vs non PI?. (Form what I understand, the major difference on the lincoln and cobra heads are the springs - cams appear to be the same)
If the newer heads are significantly better, the $$ i would spend on the porting could go to the newer heads, and then the s/c. I'll run the heads as they are now, then upgrade later?
Do the newer heads just bolt right onto the 96 teskid block?
I know its gotta be a PITA job for new heads with the motor in the car, and am just getting lazy thinking about what a job to pull the motor back out down the road and be mustang-less for a bit.
I have a 96 dohc engine that i am rebuilding and have about $2000 left for the engine. 85k Motor originally came from a 96 lincoln and already have the upper and lower intakes for it. I would like to make 450 - 500 hp on what is considered a smog legal daily driver in nj.
I can get the heads ported for about 700-$800
I can get forged internals with close to stock compression (ie forced induction later) for $1000
or
a forged stroker kit for close to $1800.
cams are another $600-$700
(slightly over budget any way you cut it but hey)
I was wondering how much of a benefit porting the heads would be - actually if it would be worth it. If I get the heads ported and the low compression forged internals, I could a a s/c down the road (does anybody make a twin screw or even a roots s/c or is a novi pretty much it?) How much benefit would porting be with forced induction... or with NO2... or with a stroker even? I belive the combustion chamber is enlarged and modified slightly during porting, so that would drop the compression a bit, but I am presuming the increased flow would make up for it.
Does anybody have any experience with porting DOHC heads and power gains?
Thanks everyone
What up Somerville, NJ
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do both or just do cams and port. it will be more worth it.
it also kinda depends on what direction you want to go as far as modifications... if you are keeping it N/A... i wouldnt say do a stroker kit because you will make most of your power on the low end... cams and port will give you massive amounts of top end.
There's no way I'd do a stroker mod motor. If you want more displacement, go for a big bore block. I'd say do a little port matching and smoothing on the heads at home with a dremel tool and save that $700 bucks for an intercooled blower. Get that forged rotating assembly, make sure it's got pistons that will drop the compression ratio a bit if you're sure you want to do a power adder.
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I have a 96 dohc engine that i am rebuilding and have about $2000 left for the engine. 85k Motor originally came from a 96 lincoln and already have the upper and lower intakes for it. I would like to make 450 - 500 hp on what is considered a smog legal daily driver in nj.
I can get the heads ported for about 700-$800
I can get forged internals with close to stock compression (ie forced induction later) for $1000
or
a forged stroker kit for close to $1800.
cams are another $600-$700
(slightly over budget any way you cut it but hey)
I was wondering how much of a benefit porting the heads would be - actually if it would be worth it. If I get the heads ported and the low compression forged internals, I could a a s/c down the road (does anybody make a twin screw or even a roots s/c or is a novi pretty much it?) How much benefit would porting be with forced induction... or with NO2... or with a stroker even? I belive the combustion chamber is enlarged and modified slightly during porting, so that would drop the compression a bit, but I am presuming the increased flow would make up for it.
Does anybody have any experience with porting DOHC heads and power gains?
Thanks everyone
Your pricing figures are completely inaccurate. First off, the port work on the heads will cost 700-1200 depending on how much work is done, etc. However, you have to add in an addition $300 for a valve job (an absolute must), $300 for bronze valve guides (another MUST), and $400-500 for good valves (not the sh!t stock ones).
Secondly, you will not find cams for a 4V motor for that cheap, unless they are regrinds. If that is the case, I suggest you find a VERY compotent builder who knows how to "tip the valves" and set lash on every valve. Regrinds are notorious for extensive valvetrain setup, and only a few people know how set them up accurately.
Unless you plan to build the shortblock yourself, you might as well factor in another $600 to assemble the shortblock, $600 to time/degree the cams, and another $300 on billet oil pump gears.
The 4V heads can make 700rwhp without any work. The stock B heads can do it, but require a little more boost to do so. A good valve job on those old B heads will do wonders. A swap to a tumble port heads is a worthwhile investment.
the price the machine shop gave me for porting the heads was $700-$800. As far as the valve job - for some reason I didn't even think of it. The cams are regrinds - and I was going to do the assembly mostly myself.
"A swap to the tumble port is a worthwhile investment" - will the good valve job on the older heads be comprable to the tumble ports at stock? Are there any issues with the tumbleport heads - I do not know too much about them. I am presuming they will also need a valve job w/ guides and valves?
Valves and cams - w/springs, retainers, cam followers... $1400-$1500.
from what I see, the part numbers are the same for 96-98 and for 99-04, so I am presuming I can buy and install on the older heads and remove and install on the tumble ports when I get them, or bite the bullet and get the new heads now. another $1400 for unloaded heads - but are presumably already "high flow" - I am not sure if they have a valve angle job or not.
Mark is right about the cost of the engine work. I've been suffering sticker shock from the prices of engine work on a 4.6. i can get one for nearly nothing $250 but the head work and block work is nearly triple the cost of a 5.0. The hole price for stages (stage1, stage2, stage3) on head work really ticks me off too! In fact i was wondering what the HP difference is to having the CNC head work as opposed to just doing some gasket matching/mild machine work myself.
sullivan performance claims that tumble port heads were also on the Lincoln Continental but i would verify before i buy. I know that the block on the lincoln Continental is useless as it is FWD. i think it is from 95-03 but again verify before you buy.
the price the machine shop gave me for porting the heads was $700-$800. As far as the valve job - for some reason I didn't even think of it. The cams are regrinds - and I was going to do the assembly mostly myself.
"A swap to the tumble port is a worthwhile investment" - will the good valve job on the older heads be comprable to the tumble ports at stock? Are there any issues with the tumbleport heads - I do not know too much about them. I am presuming they will also need a valve job w/ guides and valves?
Valves and cams - w/springs, retainers, cam followers... $1400-$1500.
from what I see, the part numbers are the same for 96-98 and for 99-04, so I am presuming I can buy and install on the older heads and remove and install on the tumble ports when I get them, or bite the bullet and get the new heads now. another $1400 for unloaded heads - but are presumably already "high flow" - I am not sure if they have a valve angle job or not.
Thanks guys
There are no issues with tumbleport heads. No, a valve job on the B heads will not compare to stock tumbleport heads. The TP heads are better suited for street cars, as they help improve low rpm/mid range power over the twin port B heads. If you have the money, I'd highly suggest switching to them.
Do you know how to assemble a mod motor, let alone a 4V? Not being a d!ck, but I know many people that think they can, but fail.
I'm also going to suggest NOT using regrinds. I've had way too many problems with them in my day, and the extra money spent for billet cores is highly worth it.
yea, im ging to stay away from the reground cams... the set for $1500, to my knowledge, has new cams.
As for my ability to assemble everything....
You never know until you try. I have taken apart and assembled close to a dozen chevy 350 and 305 - older ones as they may be. And just replaced a head gasket on a 94 4.6 out of a tbird. Granted, the heads remained assembled - and they were only 2 valve at that.
I know you're not being a "d!ck"... I completly respect your experince, intelligence, and your opinion/input. You're an engineer - I'm still in school. You probably rip apart these mod motors on something close to a daily basis. I just don't want to be a pu$$y and wimp out building my own engine until i KNOW I am really clueless. Don't get me wrong, I am not calling people who buy built engines, or pay people to build their engines a pu$$y - I may end up being one of them. Its just my preference to do it myself... or try to anyways. I have a ford factory manual book that should help me thru it, or is it a major PITA that someone who did it before should do?
yea, im ging to stay away from the reground cams... the set for $1500, to my knowledge, has new cams.
As for my ability to assemble everything....
You never know until you try. I have taken apart and assembled close to a dozen chevy 350 and 305 - older ones as they may be. And just replaced a head gasket on a 94 4.6 out of a tbird. Granted, the heads remained assembled - and they were only 2 valve at that.
I know you're not being a "d!ck"... I completly respect your experince, intelligence, and your opinion/input. You're an engineer - I'm still in school. You probably rip apart these mod motors on something close to a daily basis. I just don't want to be a pu$$y and wimp out building my own engine until i KNOW I am really clueless. Don't get me wrong, I am not calling people who buy built engines, or pay people to build their engines a pu$$y - I may end up being one of them. Its just my preference to do it myself... or try to anyways. I have a ford factory manual book that should help me thru it, or is it a major PITA that someone who did it before should do?
Thanks again
Its a lincoln mark VIII, not a continental
An engine is an engine, but there are a few differences you'll have to learn between a SBC and a Mod Motor. The mod motors are very, very tempermental to clearances, unlike a SBC which you can build with your eyes closed. Also, understanding how to degree cams on a 4V OHC engine is much more of a task than an OHV engine. It's not all that hard, but I can gurantee the first couple times you attempt it, you'll scratch your head.
The Ford factory manual will be good to give you insight on the "how to" and torque specs.
If you need help with the build, I can help out, just make a post or PM me. I've got pictures and can surely give you all the specs you'll need to build it yourself.
If you do assemble the engine yourself, you're going to need the following tools (An ABSOLUTE MUST!):
Vernier Calipers
Micrometers
Rod bolt stretch gauge (do not just torque the bolts, you MUST find the proper preload)
An accurate torque wrench
FRPP 4V Cam timing tools (OTC makes these)
Degree Wheel
Ring Filer
I greatly appreciate the help. I am almost certain I will be in need of your assistance.
As for the "scratchin my head" bit, yea, the first time I took off the valve cover on an OHC engine I was amazed by the completly new configuration. I can imagine the trouble\fun i can get into with a dohc.
I have plenty of calipers, micrometers, dial gauges, and tourque wrenches, gauge blocks, feeler gauges. From what it looks like, the cam positioning tool is just a device that clamps onto the cam and prevents it from rotating and moving during assebly - please correct me if I'm wrong. As for the bolt stetch gauge, is that pretty much a modified dial gauge on a base?
dohc port and polish? or spend $$ elswhere? 
