Today I bought a completely stock '98 Cobra convertible with 118,000 miles and a rod knock. I'll get it delivered by Thursday or Friday. I've been mostly a 2V guy and I've had one 5.0L. I think I remember the weak points being the rods and pistons on these engines. I'll probably replace the bottom end with forged internals when I yank the engine. What are some good kits? I don't have a lot of leftover money for engine work because I'd like to upgrade the exhaust. Anything I should do to the heads besides valve seals, possibly upgraded bronze valve guides, lash adjusters, and the timing chain set? I don't know how much I'll have to put into her. I'll know more when I see the condition of the block and crankshaft. Anyone know of any C heads or performance parts for sale on the cheap? I can't wait to get working on a Mustang again! Thanks, fellas...
New Cobra Owner
- Thread starter 96GT226410
- Start date
You can look at mmr for the rotating assemble..or go with some manley forged rods and pistons.
If your gonna stay n/a then I wouldn't upgrade.
I wouldn't worry about the exhaust until you get the engine fixed. You could probably get away with reusing the chains. I round replace the chain guides for sure. You can have the heads gone through by any competent machine shop. They can pressure test them to see how the valves are sealing and if possible rebuild would be good. You can replace the valve stem seals so it doesn't smoke. I wouldn't waste my time with a c head swap since you said your low on funds. Then you'll need a different intake manifold so it will cost more money.
If your gonna stay n/a then I wouldn't upgrade.
I wouldn't worry about the exhaust until you get the engine fixed. You could probably get away with reusing the chains. I round replace the chain guides for sure. You can have the heads gone through by any competent machine shop. They can pressure test them to see how the valves are sealing and if possible rebuild would be good. You can replace the valve stem seals so it doesn't smoke. I wouldn't waste my time with a c head swap since you said your low on funds. Then you'll need a different intake manifold so it will cost more money.
If the rod is knocking depending on how bad it is its possible to regrind the crank but that all depends on the extent of the damage. The crank is a forged unit.
I don't have any plans for FI right now, but since I'm rebuilding my block I might as well go for a forged rotating assembly. I'm looking around for some deals, I have an engine budget of $2,000 - $2,500. I'd really like to keep it under $2,000 so I have money leftover to do other mods (exhaust, gears, shifter, tune, and suspension).
Can I run an '03 Cobra crankshaft, rods, and heads in my '98 Cobra? I can get the heads (9,000 miles on them) for $800 locally fully assembled (although I'm told I might be better off using my '98 cams even though they have 118,500 miles on them). Any idea on which pistons? I might have to get my block bored so I imagine I'll be looking for a set of .0030 forged pistons, but I'd like to keep the CR around 9:1 because I hope to be running a blower one day. Would I be better off with '99/'01 heads? What intake manifolds would fit the 03 heads? My ultimate goal is a fun street car that's putting down 450 - 500 RWHP.
Or $250 for a complete set of '02 Continental heads with 65,000 miles on them?
Changing to 99+ heads means swapping the intake too. If your budget is tight, just have the heads rebuilt.
I get that is need a new intake for the C heads. Which intake should I use for the '02 Continental heads? Which intake should I use for the' 03 Cobra heads? Any difference between the valvetrains in those heads?
pipelinejohnny
New Member
The continental heads are c heads like what's in 99/01 cobras. 03/04 cobra heads have the same intake ports as far as bolting up a manifold but they are a different casting and will make a little more power. Not worth the extra money for what the power difference is.
You can use 99/01 cobra 03/04 Mach and marauder intakes if you want to stay n/a or go turbo, no2, centrifugal
Or you can use 03/04 cobra supercharger manifold if you want to go that route which is extremely expensive compared to other forced inductions that are much more efficient per dollar.
As long as your 98 cams don't have serious wear use them, they are very good oem cams. You only need the intake cams. The exhaust cams are the same throughout 96-04 4v.
Sent from my iPhone using the svtperformance.com mobile app
You can use 99/01 cobra 03/04 Mach and marauder intakes if you want to stay n/a or go turbo, no2, centrifugal
Or you can use 03/04 cobra supercharger manifold if you want to go that route which is extremely expensive compared to other forced inductions that are much more efficient per dollar.
As long as your 98 cams don't have serious wear use them, they are very good oem cams. You only need the intake cams. The exhaust cams are the same throughout 96-04 4v.
Sent from my iPhone using the svtperformance.com mobile app
Like stated by op.
I wouldn't swap to c heads if your on a tight budget. You have heads already..so now your buying heads and they could have possible issues costing you more money. Plus you have to swap the intake to a newer style 99-04 cobra
I wouldn't swap to c heads if your on a tight budget. You have heads already..so now your buying heads and they could have possible issues costing you more money. Plus you have to swap the intake to a newer style 99-04 cobra
I guess this all depends on how my factory crankshaft and block are. Any idea how much I should expect to pay to get my block cleaned up. 020 and a rotating assembly balanced?
Just got off the phone with L&m Engines is PA. They said that it'll be $2,500 - $3,500 for me to do my block off to them (along with that used '03 Cobra crank, used '03 Cobra rods, and whatever pistons I go with) and have them bore and hone the block, balance, and build. I think that'll put me out of reach for the C head swap. Does that sound reasonable?
Pricing is a regional thing. For a baseline, you can look at the Livernois site.
https://www.livernoismotorsports.com/machine-shop-services
They have a LOT of experience and the right machinery to deal with aluminum blocks. Which brings me to a critical point. Make SURE that whatever machine shop you hire has plenty of experience working aluminum blocks. For example, if the shop tells you the block can be bored without a torque plate, RUN AWAY.
Pistons 500-800
Connecting rods 300-500
Timing chain set 400 ish (i use the ford racing set)
Replace 32 lash adjusters 300 ish (some machine shops can get rebuilds)
It adds up quick.
Specs for an aluminum engine are tighter than Iron. For example, ring gap depends on what you will be running: NA, Turbo, etc all have different ring gap requirements. If you start NA then plan for boost then plan the gap for boost.
How do I know this? My first 96 engine was built by a shop that did mostly iron and machined it like an iron block. OOPS! That one had problems right out of the gate. My next engine was built by a shop that did mostly Chevy and Ford aluminum racing engines. It is one tight motor and not a lick of trouble after 3 years.
https://www.livernoismotorsports.com/machine-shop-services
They have a LOT of experience and the right machinery to deal with aluminum blocks. Which brings me to a critical point. Make SURE that whatever machine shop you hire has plenty of experience working aluminum blocks. For example, if the shop tells you the block can be bored without a torque plate, RUN AWAY.
Pistons 500-800
Connecting rods 300-500
Timing chain set 400 ish (i use the ford racing set)
Replace 32 lash adjusters 300 ish (some machine shops can get rebuilds)
It adds up quick.
Specs for an aluminum engine are tighter than Iron. For example, ring gap depends on what you will be running: NA, Turbo, etc all have different ring gap requirements. If you start NA then plan for boost then plan the gap for boost.
How do I know this? My first 96 engine was built by a shop that did mostly iron and machined it like an iron block. OOPS! That one had problems right out of the gate. My next engine was built by a shop that did mostly Chevy and Ford aluminum racing engines. It is one tight motor and not a lick of trouble after 3 years.
There are a couple of low cost things you can do while the engine is apart. Think about adding some or all these to your list too:
Rebuild IMRCs. The o-rings you have are dried and leaking. cost about $20.
Have injectors cleaned and flow matched. Cost about $100
Replace dried hoses - especially from evaporative canister - cheap cheap
New fuel pump, fuel filter, gas tank inlet gasket - $200 ish
TPS and EGR valve replacement - check rockauto.com for prices
Clutch, throw out bearing, resurface flywheel - Not too bad
Rebuild IMRCs. The o-rings you have are dried and leaking. cost about $20.
Have injectors cleaned and flow matched. Cost about $100
Replace dried hoses - especially from evaporative canister - cheap cheap
New fuel pump, fuel filter, gas tank inlet gasket - $200 ish
TPS and EGR valve replacement - check rockauto.com for prices
Clutch, throw out bearing, resurface flywheel - Not too bad
Plans changed. For right now I'm leaning towards getting a Teskid block hot tanked, honed and .020" bored with torque plates, and rebuilt with a Termi crank and rods and TBD pistons. I'm going to call MMR about pistons, gaskets, head rebuilding kit, and bearings. We'll see if they talk me into anything else while I'm on the phone with them. Keeping my stock B heads for now and applying the funds to other mods.
I called MMR and they said that forged pistons with pins and rings, rod bearings, and main bearings would be $1,108.86 shipped to me. Does that sound expensive? I could get a full forged rotating assembly for $1,850 with a FRPP oil pump from MMR.
That price is not out of line for new parts.
Really? A $700 difference for no rods and no crank? The rest of the kit is the same. That seems strange to me.
If that's normal I guess I'll just go with the $1,850 kit. At least this way I'll have a forged stroker rotating assembly.
I don't get why you want to buy a different crank. The stock unit is forged. A head swap won't get you anything, unless you go hog wild on NA mods. You talked about going ung forced induction some day. The B heads work just fine with a centri or turbo.
Why don't you get the car, pull the engine, tear it apart and find out what is wrong first.
Why don't you get the car, pull the engine, tear it apart and find out what is wrong first.
Users who are viewing this thread
