Crossflow tips!!

B

bookworm007

Well-known member
I just picked up a crossflow head the other day and drove 700 miles round trip to get a good US 250 motor to build up. While I am still in the part collection phase I hoping hoping to get some input on what parts to get. My goal is to get as close to 300 hp as possible and not hate driving it in town. The engine is going to have a t-5 manual tranny and I am shooting for around 9.3 to 1 compression because i would like to run on regular or plus if possible. Also this is all going into a 1965 coupe mustang which dont worry is getting matching suspension and brake upgrades. What i was wondering are these realistic goals? And if they are what type of work should i have done to the head and what cam should i be looking at importing? Thanks in advance as this engine is being design to beat my brothers 305 v8 equipped trans am. Even if i cant beat his horsepower his trans am is an 86' and weight almost 1000 lbs more :eek:
 
OK first any engine in a N/A ( normally aspirated ) that makes one or more than 1 HP per cube IS NOT an EVERYDAY ENGINE , at least not a old tech Carb combo , the 1 per cube is what I use as a standard for steetability and everyday usage , small cubes , being able to use 87 or low octane , will put a stop to that goal , But you can still build a Fun combo , figure .85 per cube perhaps a bit more thats still over 215-225 figure 3000lbs with driver and that is a high mid to 13 sec car IF its a matched combo I can tell you EXACTLY what ill will take if you( PM me ) too much to type good luck
 
From what I have seen on the forum here, the US block requires a lot of special modifications to allow the Crossflow head to even be bolted to it, so I would research what needs to be done to the block before you spend anymore money. Better yet, find a machine shop that can or will perform these tasks because if you cant get the block machined as needed, theres no sense in going any further with your project. Thats probably the reason many of the X-flow projects never get finished, they either cant find shops willing to do the work required to fit the heads, or it just isn't cost effective.
 
Why wouldnt you use the aussie block? It saves an awfull lot of work.
If you search on xrglen, you will find lotsa info, that power level has been done, but as one commentatory said it isnt really a street engine.
BTW the SOHC 4 litre engines are easier to get and will give more power.
A7M
 
as a viable street-able engine, no
as an expeirment to learn more and fool around, yes

I say that cause you will be in over your head, the price is high for so little return. it would be cheaper to turbo a log head and achive those numbers than it is to build a cros flow engine with a US block.

the fun aspect once it's going will be rewarding, but the power you want to make will be disapointing.

what's the trans am 305 HP rating?? I think it's much more possible if you went with the ALUM head, which is techinally a bolt on upgrade.
 
Well i have a good running 200 already in the car so this engine is being built more for fun than out of need. I have read the chronicals and believe understand most of the modifications that need to be made. My father used to be a plumber and made a living welding steel flanges to cast pipe so widening the deck should not be a problem. Also we have a well equiped shop so the only work that will be done by a machine shop is bottom end, and any machining the block needs.I do concede you guys know much more about these engines than I do. I also searched the forums for another crossflow build to follow and noticed not many got finished. I hope i dont fall into that hole. I know that holes in the block need to be made bigger, some filled in and other new ones made, are these things really difficult. From the crossflow how guide i sounded like a lot of it is just matching the head gasket to the block and modifying from there. I have toyed with the idea of a turbo but it adds a lot of complexity to the engine build and cost. And i have also seen a lot of turbo build that are still waiting for completion on the site. I figure going this route will require a lot of initial fabrication but when you get that out of the way its just a carbed engined with an aluminum head. I bought my 250 engine for $250 and got the head for another 300 didnt even have to ship it somebody local had one. Fella also said he could import any intake or exhaust system i wanted. And yes an aussie block would make the first part of this easier but it seems like other members have had difficulty getting all the parts needed to make a fully functional engine plus there aren't any in battle ground, wa that i know of. I could get my hands on the BA engine even know where a couple those are local, but frankly overhead cams scare me as I don't have experience tuning or working on them. Which is the big thing I love about these engines is that everything is so simple, straight forward and not cramped!!! You should look at his engine bay! I took the better part of a day just to change out the water pump. His engine is rated at 210 hp stock. Eventually he is going to pull it out put better heads on it and all that jazz at which point i will probably be out gunned at least in top end but i figure i might be able to get the hole shot at some red lights.

I was afraid that xrglens 200 hp build was not something you would want to drive every day, but 225 hp wouldnt be bad either, and maybe someday (probably when my brother pulls his engine) i will get a turbo for mine :eek: Im doing this mostly for the fact that every time i see a mustang at a show its got a v8. Its gotten to where i don't even look under the hood of them anymore because they are all the same. But i did see a turbo 6 cyl falcon at the portland Roadster Show which was awesome, but the owner was not by his car so i didnt get to chat him up.

Im pretty commited to the crossflow head I know its not bolt on but i think i can do it without dropping mountains dough or atleast not in one lump sum haha So given that i would love if I could get you help in choosing a cam that gives me a nice loping idle and all sorts of fun up to around 4000 rpm or alittle more? not sure what a 250 with a crossflow is really capable of. After i have that figured out I am going to start looking for a gasket set, and cc my head to see what i am looking at for compression ratios. I also know that that will change depending on if my block has had any work done to it. Thanks for your help!
 
Well, at least you know what is ahead of you in that respect, maybe others might not have looked into it as closely and realized it was more than they cared to get into to once they got to that point. Or maybe they found the CI head was a much cheaper and easier route since it bolts on with no mods required. Good luck, keep us posted on your results.
 
bookworm007,

Do you have a crossflow cam yet? As it's been stated on this forum, and applies to the xflow, you have to look at everything in your build; valve size, cam, intake, carburetor, exhaust, ignition, transmission type, and rear axle gearing. On the xflow, when porting the head you are better off concentrating on the intake side but more is not always better; you can actually hurt performance by porting too much.

The 4.1L xflow is limited to about 6000rpms before crank harmonics set in, so don't expect anymore revs out of the US250 bottom end. If you're going with a carburetor, the Aussies like to run the Demon 465 with an Aussiespeed 4Bbl intake. If you get a header/extractor for the xflow to run on your 250Hybrid, there might be starter interference since the xflow has a high mount and the US250 has a low mount.

Good luck. Keep us posted.
 
I do not have a cam yet. I was looking for some help in deciding on which one to get. I want something that i can make reasonable power with out going to crazy compression ratios. If I can get anywhere between 220 to 270 :roll: i would be happy. My brothers car already throw you back when you plant it and is heavier than a stang with only 220 hp when it was new. The car is going to have a t-5 and most likely 3.73 rear gears since its getting an 8.8 out of an explorer and that is the most common ratio. Thought about stealing my moms but i don't think she would appreciate it :LOL: I already have a DUI ignition system in the box just waiting to go on an engine, and i was figuring on watching for a used aussiespeed intake to pop up on Au's ebay to have imported. I don't know what i am going to do with exhaust yet....... I am half tempted to use my solid works and CAD skills to have a flange made and make some custom headers but that might be a bit too ambitious when i still have a block to modify and engine to build. If you guys were building an engine like this would you buy a set of aussie headers and modify them to fit or just just a stock manifold until you had the chance to build some custom ones? I am going to take aussie7mains advice and see what i can find in xrglen's posts about head work and cams so that maybe i can keep from making any costly mistakes. No doubt the CI head is great and if i had 2500 bucks to lay down on one part i would do it, but you loose some of the fun with straight bolt on parts. I like having to build something no one else has :) And once i start digging into this engine i will be sure to take lots of pictures and notes. Thats the one thing I wish there was more of for the crossflow heads as far as adapting them to US blocks.
 
Since you mentioned x-flow header flanges, I along with another member on here designed and have them available.
 
Ive just seen that you live near Vancouver Canada, Im now working for Westport Inovations thats based in Vancouver, Im in Perth and there might be some way I can help you, dont be afraid of the OHC six, there built like brisk dunnys and are easy to work on, they have hydraulic lifters and will eat the crossflow alive, Ive got an 2000 AU model Falcon with the VCT version of the 4 litre OHC engine, its done 220000km and runs like a top, rated at 168kw which is more than any sreetable crossflow will give.
These things are about $500 in scrappers yards, they come with a T5 or locally made auto.
Give it some thought.
A7M
PS Now Ive realised Ive made and error and that there is two Vancouvers, and your in Washington state, so I have to retract what ive said. Silly me!
However the offer to help still stands.
 
Yes I know, and my typing is pretty lousy as well, so please excuse the spelling errors.
Ive got a blown crossflow 200ci in my project XP ute, which isnt complete yet but getting there.
The cam Ive selected is a Camtech 142-503 which should be good for the 250 suggested above.
However Id still get an Aussie block to save lotsa trouble.
I dont see how parts are that much of a prblem even fron from Battle ground. BTW what battle?
A7M
 
aussie7mains: Most of the block mods will just take alittle time not so much in the way of money. Also this engine is going into a 1965 mustang and i dont want it to looks like im filming tokyo drift part 2. So how old school do they look? I have never really seen one up close i tried googling pics but came up dry. Also do most people leave those engines stock or are there some easy ways to squeeze power out? Also is the only real option to leave it injected and preserve power output? Not sure I am ready to dive into megasquirt unless the computer is stand alone and easy to retain. I am assuming ford wasnt kind enough to put the sbf bellhousing pattern on it so you would need the manual bellhousing specific to the engine?

I like using the alloy crossflow head and US block because other than vavle covers, cam, and gaskets all other parts internal or otherwise have a locally availible US replacement. If i ever came into the situation where i had to rebuild the engine any bearings, vavle train, senors ect are specific to that engine. While Im sure substitutes could be found in the US but that would take alot of time and work too.

Dont worry the vancouver thing happens all the time when i go up to Seattle. I've learned to say I'm from portland, except if i went to the east coast I would run into the same problem with portland, Maine :LOL:

CNC-Dude: How much are you asking for those flanges?
 
ford 4.0 sohc

looks like one in a mustang allready:from mustang monthly... but turbo'd

mump_0902_27_z+guide_to_six_cylinder_performance+front_view.jpg

images

try these links - all too big to post as pics



http://memimage.cardomain.com/ride_imag ... _large.jpg

http://imgc.classistatic.com/cps/kjc/12 ... ka_20.jpeg
 
The engine shown above is the later OHC engine that I mentioned, they are good, you can get cams etc and there is a carby type manifold that is from Aussiespeed, so if you fit an earlier dizzy you can run it just as a carby engine. The cast exhaust manifolds are pretty good, as I said they go to 172kw with it (and VCT), so you could probably get around 215bhp without too much effort even with a stock cam.
The pics shown above are a propane fueled 65 mustang turbo which is callef 1tuf65, its found on youtube and has run a 9sec et, its fast.
I stll dont understand why you would want to stay with the ealry blocks when the late ones are so much better and cheaper.
A7M
 
as another fyi - the OHC engines are taller than the pushrod 6's - even a 250 pushrod six. . due to the cam (obviously) being on top of the head.

a few people have transplanted these into the early falcons here in australia ( ie up to 66 etc- ) but i could count on one hand the number i have seen (in real life and the web) but its not very popular and i think the reason is the height - and the width with the std intake manifold hits the spring towers.

if you lower the engine (to get clearance under the bonnet (Hood!)) then you run into problems with the sump hitting the steering drag link -

so probably need rack n pinion steering

and any crossmember you may have may hit the sump .


certinly not impossible- but seems to be a reason people go for the pushrod crossflow over the Ohead cam later 4.0 six


so if going that way - then measure carefully
another FYI :
i am not sure - but 'think these are front sump - which is fine - but maybe someone else can chime in here and confirm
 
Yeah they sound like great engines, but i would rather modify a block then have to cut up my engine bay since a 250 is already usually a pretty tight fit in an early mustang. Plus the number of parts i would have to keep on hand is also troublesome. Even if they are easy to work on i would have to keep multiple spares for everything from water pumps to distributor components because if something broke and i did not have it i would have to either pay huge air shipping costs or wait 3 months for it so arrive in a crate. I have a 1968 bronco that is going to need a new engine and we had planned on using a 302 but maybe we would look into one of these gems. The crossflows still seem fairly popular in some circles and a lot of times working with an engine that others consider out dated is a good thing because it allows you to find used parts cheap! :D

So i am now looking at crow cams 14650 or 14892. I want the first one but think the last one might fit my engine better.
The 14650 has 230 advance, 113 lobe separation, and .522 valve lift. It describes the cam as follows: Rough idle, excellent mid range power. Needs
improved breathing. Power is supposed to come in from 2800 to 6000 which is taking the power range rather close to the limit of our stock bottom ends, but i did some reading and this appears to be the cam that xrglen used to put in his 300 hp build, but since i dont plan on doing anymore port work than just cleaning up the ports it might be too much cam for my engine.

The 14892 is designed to get max performance from street engines which sounds good so far, it still requires aftermarket springs and retainers, but it only has a duration of 214, lobe separation of 112 and a max lift of .510 and its rpm range is from 1800 to 4800. Which sounds great it has pretty good lift, will pull from real low to the max rpm a daily driver is going to see. I just hope the idle is lumpy enough for my liking. Do want this thing sounding too tame :eek:

I am hoping with the 14892 cam, about 9.2 to 1 compression, DUI, good exhaust, ect I can hit some where close to 250 hp.

One more question i had at what point to you have to start using a taller valve cover or spacer? will stock cleveland valvetrain fit under the stock valve covers?
 
Also is a 2 barrel carb going to be good enough to power this engine or would it require a 4 barrel? Just looking into what intake to get.

CNC-DUDE: And what are the flanges made from?
 
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