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Yes, will plan on a custom tune, but the good tuners are around 3 hrs away from me so hopefully the stock ecu will run it fine to get there.
I just got a line on some used TFS 170 heads. $1700CAN. That’s about $1300 US. Assuming I’d still have to spend money getting them checked over I’m not sure it’s a great deal. At least new heads would be a direct bolt on without added machine shop cost. Was hoping to find some used GT40x aluminum heads, but no luck so far.
Yes that is steep. I would buy them new. For the few hundred saving its not worth the hassle. The TFS 170 11r heads give you slightly better gas flow behavior due to the rotated valve position. Not much in it when compared to AFR ..but it helps. Also helps slightly with piston to valve clearance with higher lift cams.
Just get them new....that way all springs and seals and surfaces will be perfect. Just make sure you pour lots of oil over the valves before sealing with the valve cover. I even use a syringe to make sure the valve stem seals are properly soaked before I seal them up.
You will have a good experience with new heads, used heads can be warped, have a bad seal etc.
Well, all the reading I've been doing over the last couple days leads me to locking in the AFR 165 58cc heads. https://www.jegs.com/i/AFR-Airflow-R.../1399/10002/-1
They are ready to bolt on right out of the box. If I buy used heads I'd need them checked over and who knows what expense to make them as new.
With a ported Cobra lower and the heads chosen I think I have all the info I need to contact Ed Curtis about a cam, though it looks like the Comp Cam XE's are a good off the shelf choice.
Well, all the reading I've been doing over the last couple days leads me to locking in the AFR 165 58cc heads. https://www.jegs.com/i/AFR-Airflow-R.../1399/10002/-1
They are ready to bolt on right out of the box. If I buy used heads I'd need them checked over and who knows what expense to make them as new.
With a ported Cobra lower and the heads chosen I think I have all the info I need to contact Ed Curtis about a cam, though it looks like the Comp Cam XE's are a good off the shelf choice.
Excellent. That sounds like a much better plan than the one in Post 1
Yes the new AFR 165 heads will be perfect and Ed's cam will give you a solid 20 hp over the XE cams, I have simulated the XE cams against Ed's cams with Dynomation for years and Ed wins every time and by a good margin. Just make sure you get a billet Steel cam from ED AND you double check that you have a steel gear distributor.
Looks like you are set Brad It will be good for around 340-350 FWHP.
How about I throw another curve ball.
Since I freshened up this engine with new rings and gaskets only about 10k miles ago, and it runs strong minus using some oil- I’m thinking of bolting the new heads and intake on the existing motor....for now.
I’ll maybe do a compression test and see if I can’t determine the reason for the disappearing oil, but if I can run this setup for this year, it’ll give me time to research and build up (or buy) a shortblock maybe next year.
Car is away till spring so I could change my mind 1000 times before then. In the meantime I’ll keep stockpiling the upgrade goodies.
Your oil consumption if small could be from the following areas:
1) Excessive piston bore clearance
2) Rings (excessive end gap, installed upside down or gaps out of correct rotational alignment)
3) Bad valve stem seals
4) Bad cross hatch in bore
1) The Piston to bore clearance should be around 1 thou for cast piston and 2.2-3 thou for forged. Larger clearances will increase of oil slipping through. It will be slow though. In your case if you did not buy new pistons and or machine the block then this could be where your oil consumption is coming from.
2) Rings need to be installed with the right end gap as checked in the bore. For these engines the top ring should be around 18 thou and the lower ring around 20-22 thou. The ring MUST be installed with the pip or dot facing UP. This is easy to miss if you are rushing, working late at night or were never shown how. Even now I always triple check my work here. Same goes for the oil rings, the expander rail must be installed correctly so as not overlap the ends so the oil rings sitting correctly. The end gap alignment for all rings needs to be correct as well. The oil rings need to be aligned as follows with 12 o clock on the piston being the FRONT of the piston that points forward:
Bottom oil ring at 11 o clock
Expander at 2 o clock
Top oil ring at 7 o clock
Second compression ring at 9 o clock
Top compression ring at 3 o clock
3) Stem seals are a very common area for oil consumption, the seals allow oil to creep past at slow engine speeds like idle. If it smells oily at idle then chances are its these things. Sometimes if you don't lubricate them if new at assembly they burn up fast due to running dry for a little on first start up until the oil comes up (that's why we always need to pre prime an engine's oil pump and lubrication system prior to first start) . This makes them wear abnormally fast. The valve stem seals always come up a lot for oil consumption issues....if it smokes or smells at idle, but full power looks clean (i.e. not smoky) then it is probably the valve stem seals. The valve stem guides are also an area of oil seep, many people do not replace the guides when they rebuild the heads (mainly due to cost), this can lead to slow but steady oil consumption...again mainly at idle. Replacing the valve guides is costly and it is much better value to just buy new heads.
4) If you just do a re ring (i.e. no bore machining) then there is a chance that the rings don't fully seal 100%, due to the bore being too smooth with no cross hatch. A compression test will reveal this quickly though.
In your case all of the above need considerable effort to investigate and or rectify. My advice is that you will remove the top end, valve stem seal and guides issues with the new aluminium heads...and if you have time on your hands and or funds, a new shortblock (rebuild yours or buy new) will fix the others...you can then sell the existing engine to cover some of the costs. That way you will get the best result.
Do it once and well is my philosophy...especially in these cars where the packaging is tight and the effort to get to things is higher.
Well, my plan is underway.
I bought some cheap Flotek heads back in the spring, had them checked over and ready to go. Bought an Explorer intake manifold and sent to TMoss for porting. Also got a 65mm TB and EGR spacer and E cam.
I pulled the motor last week and dropped off to the machine shop on Monday. They’ll get back to me this week with what needs done. Took tranny to the guy who built it for a quick checkup, and brought all my pretty parts to the powdercoater.
I was surprised the amount of carbon on the tops of the pistons when I pulled the heads. I got good compression readings but obviously had a lot of blowby. Happy to finally get this done.
Another perk: I really lucked out finding this powdercoater. He does great work for very reasonable cost and is also a master fabricator. Anything to do with metal, he can do it.
Edited to add:
Machine shop called me this aft. They’re boring the block .30 and decking it. They’ll have it done next week sometime. I have a busy week and won’t be able to finish assembly till the following week. Not that there’s a rush....I won’t be able to get it back on the road till spring.
Well, my plan is underway.
I bought some cheap Flotek heads back in the spring, had them checked over and ready to go. Bought an Explorer intake manifold and sent to TMoss for porting. Also got a 65mm TB and EGR spacer and E cam.
I pulled the motor last week and dropped off to the machine shop on Monday. They’ll get back to me this week with what needs done. Took tranny to the guy who built it for a quick checkup, and brought all my pretty parts to the powdercoater.
I was surprised the amount of carbon on the tops of the pistons when I pulled the heads. I got good compression readings but obviously had a lot of blowby. Happy to finally get this done.
Another perk: I really lucked out finding this powdercoater. He does great work for very reasonable cost and is also a master fabricator. Anything to do with metal, he can do it.
Edited to add:
Machine shop called me this aft. They’re boring the block .30 and decking it. They’ll have it done next week sometime. I have a busy week and won’t be able to finish assembly till the following week. Not that there’s a rush....I won’t be able to get it back on the road till spring.
Hi Brad,
Great work getting it started!!. Things are looking good...
I would only suggest that you consider a better cam. There are likely much better options out there. I am not sure which Flotek heads you have but there is a bit more flow to be had when the lift goes over 0.5 in, you B3030 cam does not even lift 0.5in. If you have your heart set on the B303, then use 1.7 ratio rocker arms to get a bit more lift and therefore torque.
Also a 70mm TB would a better proposition too..but 65mm is OK.
Looking forward to you putting it all back together again and reporting back
Great work getting it started!!. Things are looking good...
I would only suggest that you consider a better cam. There are likely much better options out there. I am not sure which Flotek heads you have but there is a bit more flow to be had when the lift goes over 0.5 in, you B3030 cam does not even lift 0.5in. If you have your heart set on the B303, then use 1.7 ratio rocker arms to get a bit more lift and therefore torque.
Also a 70mm TB would a better proposition too..but 65mm is OK.
Looking forward to you putting it all back together again and reporting back
cheers
Yes, that was a decision based purely on economics. I talked to Ed Curtis about a cam, and his price was decent...about the same as an off the shelf Comp Cam, but the springs on these heads will only support up to .550 lift. His upgraded spring package cost more than his cam. I got the E cam basically for free so it was an easy decision to do that for now, and save up for a custom cam and springs for next year. At least I know I’ll have a good bottom end to build on. The 65mm TB was a deal I couldn’t pass up. Though not optimum, it should still be a pretty well matched combo.
We start assembly tonight.
I am rebuilding my 302 this winter and I've been collecting parts like gt40 heads I plan to Port and polish, a tunnel ram and 1 5/8 headers.
Matching flow rates makes total sense.
Where do you get the flow numbers for the intakes and heads, do you have your own flowmeter you use for measuring?
I'm curious how I would measure the improved flow after my port and polish.I know how I can do a single port with a vacuum and a mercury gauge, to measure relative improvement.
But I don't know how I would flow the whole head (or intake) and get an absolute number.
Thanks for all the super helpful replies engineer!
PS, my build is for a track car more than street car. So low rpm torque and grunt matter less than smooth high rpm operation and peak hp.
Last edited by walkingspanish; 12-20-2019 at 12:54 PM.
I am rebuilding my 302 this winter and I've been collecting parts like gt40 heads I plan to Port and polish, a tunnel ram and 1 5/8 headers.
Matching flow rates makes total sense.
Where do you get the flow numbers for the intakes and heads, do you have your own flowmeter you use for measuring?
I'm curious how I would measure the improved flow after my port and polish.I know how I can do a single port with a vacuum and a mercury gauge, to measure relative improvement.
But I don't know how I would flow the whole head (or intake) and get an absolute number.
Thanks for all the super helpful replies engineer!
PS, my build is for a track car more than street car. So low rpm torque and grunt matter less than smooth high rpm operation and peak hp.
Hi Walkingspanish,
Firstly your questions answered…
1) I get my flow numbers from the internet I mainly use the manufacturers flow rates..but occasionally some head tuners and magazines online publish some great data, here is a slightly older article from Fordmuscle but it is still a great resource of info for small block ford head flow rates...
2) Measuring your port and polish improvement at home is not difficult as you can indeed make your own flow bench..its a bit tedious but can be done..see this article if you are keen to go down this road Flow Bench
Now if you wanted my input...for whatever its worth
1) if you want to make a more race orientated engine then you MUST get rid of the GT40 heads. They barely flow 200cfm in stock form. Secondly even after porting polishing etc you can only expect them to hit 220cfm...no way near enough o make any power for a racing style of engine.
2) Save yourself the head ache and hassle and save up for a set of AFR or TFS 185 or 190cc aluminium heads. They flow 300cfm out of the box...bolt on. Well worth the money. Its a massive difference and it will make you much more power. You need to have a min of 250 cfm intake flow to make any real horsepower.
3) You need a comparably high flowing intake to match up to the flow rate, Your tunnel ram may do it...I am unsure what brand or type it is. Just make sure it can flow 300cfm per runner too. Or again save up and look at an Edelbrock Victor Jr or super victor they flow close to 300 cfm. Some of the Performer range can get close to 250 cfm. Up to you how far you want to go...but needs to be as strong as the head flow in cfm.
4) Carburation look at Edelbrock AVS2 650 cfm (great carb, air valve secondary, jet changes without taking carb apart etc...its very tuneable if you know them and will make just as much power as anything else under 550 HP if properly tuned. If going above this power level you need something more specialised). I have used them for many many years (way back in the 80's Carter Days) and they are super great for driveability and throttle crispness. They will deliver more than enough grunt for your 302...and it will start every day But if you must go holley look for a Quick Fuel Technology Holley with 650 cfm
5) Cam...look at a billet steel custom cam. off the shelf cams are always a compromise. Its mildly more expensive but worth every cent as you get every last bit of power out of the engine. Shoot for 228-235 deg of duration @ 50 thou lift AND go for an overall valve lift that matches your head flow's potential..i.e. if your head flows 300 cfm at 0.6in then get the cam to lift that much too...most off the shelf cams stay under about 0.57 in lift...leaving power on the table. The 228-235 @ 50 cam will be driveable but will have a lumpy idle...but not bad enough where its a pest to drive. There are larger cams that can give more power....say around 245 deg of duration @ 50...but the driveability is not great...better to undercam slightly and have it be driveable, so you can use the car when not racing it.
6) keep compression around 10-10.5:1 - with cranking pressure around 185-195 psi
7) Invest in good rockers and valve springs to handle the lift (around 150-155 lbs on the valve seat...PAC dual spring setup )...if you get the AFR or TFS heads the springs are already done for you.
8) Good roller rockers...shaft design is better (more stable) that stud mount for high rpm (5000-7000 rpm) but costs a bit more...stud design is OK,..just get the thicker rocker studs option if you go studs.
9) Rear end Gearing will need to be about 3.7 - 4.1
10) Use a Tremec TKO 500 or 600 transmission..Tremec/Ford Racing T5z...may be OK for street but if racing it...it will be very marginal
Above should net you a solid 400hp at 6600-7000 rpm with a good mid range torque band...and be driveable on a sunday
2) For the GT40 heads, ouch! I thought with porting and polishing I would be able to bring them to 250 cfm range. I've managed to keep the whole build really cheap so far, so I think I can splurge for the heads.
3) I found an old Weiand Tunnel Ram, I believe it's a 1988 (https://www.summitracing.com/parts/wnd-1988), it only has the single carb upper intake though. I figured that was fine.
4) I am running a Holley 1850 right now. I figured that will probably get me going for now, but I'd prefer mechanical secondaries for track usage. I'll look at the Edelbrock!
5) Any recommendation for custom cam makers? How much am I looking at for a custom cam?
6) Is 10.5 the max I should go, or is that pretty much the max for pump gas?
7 + 8) Yeah roller rockers for sure. Any recommendations? I was going to get the thicker studs and cam stud girdles. Are shafts that much better?
9) Yeah, I need to decide on the wheel / tire sizes so I can finalize what gearing want to run.
10) I have a BW T5 I picked up fro $140, so that's what I'm going to initially use. I figured it would let me easily swap to the TKO500 in the future.
Do you think I'll be able to get 400 ish hp? I've been checking out dyno charts and I notice getting over 300 from a 302 seems to be a challenge!
2) For the GT40 heads, ouch! I thought with porting and polishing I would be able to bring them to 250 cfm range. I've managed to keep the whole build really cheap so far, so I think I can splurge for the heads.
3) I found an old Weiand Tunnel Ram, I believe it's a 1988 (https://www.summitracing.com/parts/wnd-1988), it only has the single carb upper intake though. I figured that was fine.
4) I am running a Holley 1850 right now. I figured that will probably get me going for now, but I'd prefer mechanical secondaries for track usage. I'll look at the Edelbrock!
5) Any recommendation for custom cam makers? How much am I looking at for a custom cam?
6) Is 10.5 the max I should go, or is that pretty much the max for pump gas?
7 + 8) Yeah roller rockers for sure. Any recommendations? I was going to get the thicker studs and cam stud girdles. Are shafts that much better?
9) Yeah, I need to decide on the wheel / tire sizes so I can finalize what gearing want to run.
10) I have a BW T5 I picked up fro $140, so that's what I'm going to initially use. I figured it would let me easily swap to the TKO500 in the future.
Do you think I'll be able to get 400 ish hp? I've been checking out dyno charts and I notice getting over 300 from a 302 seems to be a challenge!
Thanks so much for all of the help!
OK sweet..,my answers below...
2) Great...glad you are going for the head upgrade. You wont regret getting better heads...that is where all the power is..
3) Tunnel ram should be OK...I will look at the flow figures if I can find any..
4) The Holley 1850 is OK. However mechanical secondaries will always give a better "feel". The Edelbrock AVS 2...is actually the best of both worlds...it has mechanical secondaries BUT they are fed by an adjustable air valve. Which means the air valve wil open when the engine air speed demand is high enough to allow the flap to open. It will bring a smoother transition from part throttle to fullpower….and its super tuneable too..as you can adjust the both the mechanical secondaries AND the air valve for precise secondary actuation. Also the Edelbrock AVS 2 has annular discharge boosters too for superior fuel atomisation. PLUS you can change the step up spring (power valve), metering rods (jetting) all without taking the carb apart.. try getting all of that functionality from your holley
5) Ed Curtis at Flow Tech Induction does the best custom cams for Fords. Cost is around $400 USD...worth every cent...just make sure you get a billet steel cam core. The Austempered cores are cheaper but they are NOT as robust as the steel cores. So chances of rounding the cam lobes is higher...been there done that...Billet Steel only now for me
6) 10.5 is about right for street/strip duties with an aluminium head and a mild to medium duration cam (220-230 deg @ 50). With iron heads the compression ratio value is less by about 0.75 points. So for example a 10.5:1 aluminium head engine can tolerate the same fuel as say a 9.75:1 iron head engine. If your cam gets larger with longer duration you can go higher on the compression with either heads. Aluminium heads give you a much better capability for increasing compression. Keep it between 10-10.5:1 on aluminium heads and 9.5-10:1 on iron heads with a 220-230 @ 50 deg cam. The Aluminium headed engine will run better though with everything else being equal due to increased compression...it will feel perkier on the throttle...less soggy.
7) Are Shaft rockers better ? Yes, by far if you are running constant high RPM in a racing engine...for short burst racing or the street then the studs are fine...with girdles even better. Check out the Jesel shaft rockers here Jesel Pro Series Rockers - SBF TFS TW11R - FlowTech Induction. For roller rockers I use the trickflow branded ones which are made by scorpion, but other brands are also very good i.e Yella Terra). Shafts are indeed better but they are double the price, if you are circuit racing for long periods of time or you need a bullet proof setup...then get shaft rockers..otherwise studs are OK.
8-10) The T5 wil be Ok for a while in a miata...but when it goes get a TKO..its a much stronger unit than the T5.
Yes it is not super easy to get 400hp from a 302 and have it be useable on the street, however if you provide a chunky custom cam (about 230+ deg of duration and 0.6 in lift), rev it to 6800-7000 rpm and have a great flowing 300cfm induction setup (heads and intake and carby) it will get there...or very very close to it.
As an example Trickflow rate their SBF top end package at 350 hp on a 302 with 250cfm of intake flow from the 170 11R head and the track heat manifold and a 220 @ 50 cam. So with an extra 20% of intake flow and more cam you will easily get the extra 50 hp you need to hit 400 hp...
OR you can go stroker...that is an extra 30-40 hp straight off the bat with the extra capacity...not to mention the torque..
I would take the stroker any day (331 is my choice) ....torque is soooo much better...
I want something that likes to rev, and I was concerned about the stroker kit adding too much vibration. Is that true?
Also, why 331 and not 347?
Another thing, is it worth reconditioning my block or should I make my life easier by starting with a DSS or even a short block and going from there?
And when should I give up and buy an LS? :-)
OK...
1) strokers can add more vibration....however if the engine is balanced properly it will be negligible. This is most important, many shops think close enough for balance is OK. However strokers need to be balanced a little better than close enough o ensure that they are smooth running and rev nicely.
2) Your rev limit goals need to be realistic. The ford small block is not a rev monster. Most street based (i.e. not race dedicated) strokers stop giving power at around 6600-6800 rpm. There is little point pushing them past this for more power. I like to cap the rev limit to 6000-6250 when using a stock block and around 6600-6800 rpm with an aftermarket block. Engine speeds greater than say 7000 rpm will start to reduce the life of the engine. An engine with a rev limit of 6500 rpm will last a very long time if built properly, plus the extra 500 rpm will likely only yield a few HP more anyway...not worth stressing the engine for another say 10 hp.
3) Why a 331 ? Well for me the piston has a larger skirt than the 347 and as a result will be able to support it a lot better. The 347 piston is very short on the skirt so it rocks around a bit more. Secondly the piston ring intersects the gudgeon pin and I don't like that personally for a long life engine. It will also use more oil and can be smellly as well on the exhaust as it will burn a little more oil. Also the 331 requires no block clearancing which is handy. Plus the rod to stroke ratio is more favourable for the 331. However when using an aftermarket block to make a 347 things change. Pistons are larger but stroke is same as 331 at 3.25in, so rod to stroke ratio is the same AND the piston is the same skirt height as the 331. AND the oil ring situation is gone.
So if you have an aftermarket block then its 347 all the way with a 3.25 in stroke...
4) Up to you if you wan to use your block or not...HOWEVER if you are serious about racing the engine and giving it a hard time ALL the time, then I would strongly advise that you use an aftermarket block for the build. The stock block is ok for the odd burst of anger but sustained load under race conditions (i.e. circuit or long distance edurance racing) will push its limits. Plus its not much more these days for the aftermarket blocks. They are better in every respect...except 1. They are heavier by a fair few lbs.. I would buy a stroker short block with aftermarket block (Dart or Ford Performance)forged pistons ( I like Mahle) and forged crank (Scat is fine) again if you are really going to race it hard and go from there. DSS, CoastHigh, Fordstrokers and even ford performance (507hp 363!!) have good short and long blocks for you to pick from.
Engine is finished, in the car and driving.
To recap, I have a '94 block that has been decked and bored .030 over. New pistons, polished stock crank, E303 cam, TMoss ported explorer lower, explorer upper, Flotek 180 heads, PRW roller tip 1.6 rockers, 65mm TB and functioning EGR spacer. Stock MAF 19 lb injectors. Stock EECIV FI system, 3G alt.
Good news is that my bubbling coolant issue I was having pre rebuild, is gone. Also, I have NO leaks whatsoever. I've been putting some break-in miles on it over the last couple days. Sounds like I may have to go back and redo my rocker adjustment, getting a bit of sewing machine type clatter. I've been pushing the RPM's up gradually. I have about 300 miles on it now and it seems to pull hard, but I have a few issues that I'm certain are electrical in nature. I have the dreaded low speed bucking and even at cruising speed when you let off the gas it feels like a harsh transition. Kinda like you're full on or full off the gas....no easy cruising in between. That translates to it being a handful in stop and go traffic.
I've done a TON of reading on this, as it was doing the same thing pre rebuild.
I have checked all the usual stuff:
Pulled codes- only the air pump delete codes come up, cylinder balance tests good
Vacuum leaks- none, pulling about -13- -14hg at idle but steady
TPS
all other sensors are new except MAF (but I get no codes)
Varied timing from 8* to 14*
Adjusted throttle stop ad nauseam
Unrelated, my T5 is making some strange clicking noises at speed. I'll see what the rebuilder thinks. Otherwise I am on track to have a pretty nice car if I can just get this damn bucking solved.
I suppose I'm going to need a tune.
Just added: just went out to start it again and it would stumble and stall. Could not get it to stay running until I unhooked and reconnected the battery.
You need a tune, I had the same thing with mine running trick flow stg 2 cam. Tuner was able to work it out for the most part, car was no fun before it was tuned.
Curious what that cost, and what issue(s) if any he wasn't able to tune out.
I'm almost considering going Megasquirt. Not sure if that would be over my head though.
It was $600 including cost of chip. The gas mileage is much better, pills much harder, and the surging is pretty much gone. He does street tuning, and the day he had the car it was raining, so I have to take it back in the spring when the weather clears for some WOT tuning. There is still a slight surge below 2,000 rpm, has to do with cam. He’s going to try to work on it a bit more. Also has to fix a cold start issue where it stalls first attempt when cold, is fine second attempt. I had a MS in this car when it had turbo 4, I hated it. This runs way better than I ever had that MS running. That’s just my opinion, I’m not a trained tuner. I had original MSPNP, felt it did not have enough tables to get a smooth tune.
Just added: just went out to start it again and it would stumble and stall. Could not get it to stay running until I unhooked and reconnected the battery.
Your engine compartment looks awesome! It could be a factory car that just rolled off the assembly line.
When you unhooked and reconnected the battery you wiped out the "learning" memory of the ECU and restored it to factory "default." The fact your car runs better on a default tune than after it has been "learning" based on sensor inputs under real world conditions suggests "bad info" is being fed to the ECU, resulting in A/F ratios/timing adjustments that are contrary to actual engine needs.
Double check that your wires to the left and right oxygen sensors are not switched. That could create the behavior you suggest.
If it isn't that look for something else giving the ECU errant info and causing it to adjust A/F in the wrong direction.
01-15-2019, 03:54 PM
