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Author Topic:   Runner size for a 355cid?
xhubby
Dirt Full Roller

Total posts: 74
posted January 26, 2003 02:37 PM
Are Iron Eagle heads with 215cc runners too much for a 12.5 to 1, 6" rod, 355cid, with a 4412(gas)2 barrel? Thanks.

sixwillwin
Dirt Freak

Total posts: 215
posted January 26, 2003 03:01 PM
I have the 215s on a 355 and I wish I had went with the 200cc runners. That is with a 4412 also. Just my experience....sixwillwin

Monster
Dirt Maniac

Total posts: 135
posted January 26, 2003 04:31 PM
I have found that size runner is just right, at least on my combos. Don't put too big a cam in it, and select an intake manifold with an eye toward maintaining port velocity. This is with a 2750lb car, on 3/8- 5/8ths mile tracks.

mtwrght29
Dirt Full Roller

Total posts: 32
posted January 26, 2003 05:43 PM
i run the same motor an 1/4 mile tracks and jr motorsports and isky cams said to go with the 180 runners so thats what i did no complaints

xhubby
Dirt Full Roller

Total posts: 74
posted January 26, 2003 08:09 PM
Our car weighs right at 2500#,& we turn about 6400 to 6700 rpm on a 3/8 mile track. The main reason I was asking, is a friend has these heads for sale at a pretty good price, but if the runners are'nt what I need, then I'm gonna pass on them. What exactly are the results of running heads with too big of runners? I'm not much of an engine wizard (as you can probably tell) so I thought I'd get some advice from those who are. Thanks guys.

racer1030
Dirt Roller

Total posts: 22
posted January 26, 2003 08:34 PM
If the head is too big the motor wont run off the corners. A 215 cc head,on gas, in a 355 will want to turn 7500 or more and you will run out of carb first. On alchohol you might get away with a runner that size because alky needs about 5% more runner volume than gas.

sixwillwin
Dirt Freak

Total posts: 215
posted January 26, 2003 10:03 PM
my results have been exactly what racer1030 said in his post.

stockcar5
Dirt Full Roller

Total posts: 63
posted January 27, 2003 12:24 PM
with a 2bbl i would stick with a 180 or 200 cc head. i have run both and the smaller runner has given me more torque than the larger runner.


luke

sdhnc29
Dirt Freak

Total posts: 467
posted January 27, 2003 06:27 PM
Unfortunately , you must find a happy medium between high port velocity and port volume . It's been my experience that higher compression (15:1) 2bbl engines like the 215 Iron Eagle much better than the 180 or 200's . If a guy is limited to a lower compression ratio due to rules , then the smaller head's would probably work a little better . If your rule book does not have a compression rule , I'd suggest getting up to at least 15:1 and using the 215 head's , which we have found to be the "happy medium".

The last 2bbl engine that we did was a 362ci , 3.450 stroke , 6.200" rod ,215 Iron Eagle ,2926 Super Victor , flat tappet solid cam , 15.5:1 , with a bone stock 4412 . This engine had 480hp at 6,400 rpm and 474.5 ftlbs of torque at 4,700 rpm . The whole key to these 2bbl engines is compression ratio , head and cam choice . It's also important to take as much dome out of the piston as possible , as with any engine . The heads that were on this engine were angle milled down to 35cc chamber's , and the dome was eliminated down to practically nothing . All of this work improves flame travel , and ensures a more complete burn in the chamber .

My suggestion would be to buy the head's , raise your compression ratio , and go win !

Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780

xhubby
Dirt Full Roller

Total posts: 74
posted January 27, 2003 09:40 PM
sdhnc29,
What cam did you run with this 2bbl motor & how was it on dry tracks? Our track starts out tacky then turns dry & slick. My son is real good with the throttle on dry tracks but he's never driven anything with that much HP.

sdhnc29
Dirt Freak

Total posts: 467
posted January 27, 2003 10:52 PM
All of our cam's are custom ground by Crower , and so was the one used in this combo . I don't use any book ground cam's . The feedback that I received from the driver was great . This engine was used on a 1/2 mile track in Illinois that went from hooked up at the start of the season , to dry slick in the summer , and back to hooked up toward the end of the season . He was quite happy with the cam choice , though it forced him to be on top of gear changes , and used throttle control when thing's dried out .
Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780

d4490
Dirt Maniac

Total posts: 113
posted January 28, 2003 06:27 AM
sdhnc29,

Do you have a rule of thumb for port size vs. motor size/c.r./r.p.m./cam grind? What about a motor that has to use stock manifolds (intake & exhaust). BTW, I run Ford motors.

sdhnc29
Dirt Freak

Total posts: 467
posted January 28, 2003 11:31 PM
Actually yes and no . Many different engine builder's have different idea's about what work's for them . Most , us included , have come up with different combo's through a lot of R&D work , and year's of experience . 7 or 8 year's ago I would have told you that a 357ci super late model engine would not run well on race gas with an intake runner larger than 248 - 255 cc's . But now our SB2.2 357ci engines run an intake port volume of 290cc's , and produce 774 hp and 560flbs of torque . So you can see how the small intake runner theory is totally blown out of the water ! Basically , each engine we produce is tailored around the exact need's of the customer and where they are racing .

I'll be honest in telling you that I have hardly any experience with Ford engines using stock intake and exhaust manifold's . We have in the past , when we were in CA , and even now that we are in NC , worked quite a bit with Chevy engines that must use these component's , and have several cam , head , and short block combo's that work well . Most of the Ford circle track engines that we have built , have been super late model engines , or steel engines with more open rules than you are describing .

Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780

dirtbuster
Dirt Freak

Total posts: 353
posted January 29, 2003 09:03 AM
SDHNC,

What would you reccomend for runner size for a 383 or 377. 13:1 comp, steel heads and flat tappet cam, 4 barrel carb, IMCA type modified.


sdhnc29
Dirt Freak

Total posts: 467
posted January 29, 2003 11:25 AM
I assume that your running Alky , so I would suggest using the 230 Iron Eagle or Pro 1 aluminum head if you can get away without being claimed . A good book grind cam if your using Alky and running on 1/4 -
3/8 mile tracks , is the Crower 00351 cam has proven in our test's to be a good choice , if you don't want to invest in a custom grind .

Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780

dirtbuster
Dirt Freak

Total posts: 353
posted January 29, 2003 01:26 PM
sdhnc,
Are you saying that with alky you need a bigger runner compared to gas?
say 215cc for a 355, 230cc for 377/383 what about 406.

We never turn more than about 7300 rpm(355; less with a bigger motor) on a big 1/2 mile track.

thanks for your help

Also what do you think of ISKY cams? ARe they comparable to the Crowers you speak of?

sdhnc29
Dirt Freak

Total posts: 467
posted January 29, 2003 06:05 PM
Yes , Alcohol engines love big intake runner's !!! The 230's would also work quite well on your 355 . Most of the 355 alky engines that we build are 15.5:1 with an intake runner volume of at least 248cc's . But these are not with Iron Eagles .

As for cam's , I don't really have an opinion on Isky cam's because I don't use them . We exclusively use Crower . We have had a relationship with Crower for over 15 year's , and have done a lot of R&D work with him on Alcohol cam grind's in the past , including some of the first inverse radius cam's that he was making back in the late 80's and early 90's . In my opinion , he is on top of the cam grinding business . If Isky has a grind similar or the same as the 00351 , then it should work the same as Dave's cam .

Steve

------------------
Hendren Racing Engines
Rutherfordton , NC
(828)286-0780

armintroutracing
Dirt Roller

Total posts: 18
posted February 13, 2003 03:49 AM
I run 230 cc on my 383 runs as good as the 406 motors i run aganist.

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