Author Topic: gaining ground clearance.  (Read 7142 times)

Offline wideopen231

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gaining ground clearance.
« on: January 23, 2021, 10:36:58 AM »
 After some test runs although very limted due to panic a demic. I need to gain some ground clearance . Best option even though limited is lower powertrain in chassis. I can lower motor about 1.5" before heads hit chassis. Lowering will allow me to lower rearend the same. I will have to move it forward about a inch due to how I made mounting plate. I can basically rework mid plate and make new front plates. I will have to rework my anti rotation tabs.

 I could lower rear end more but would require tilting engine at front upward angle. Not sure that would be best. I figure wuth the 2.25" I have a mid plate niot(closest point) adding 1.5 inches will make loading and unloading easier.A big plus will be not getting my ass slammed every time I drive over high spot or hit small dip in return and pit road.

Only other way to gain would be taller tires running 32's now which are actually  slightly over 31 tall race ready,there is part of my screw up on build.

Thoughts good or bad on this approach?
Relecting obama is like shooting right foot because it did not hurt enough when you shot left foot

Offline Supercat

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Re: gaining ground clearance.
« Reply #1 on: January 23, 2021, 04:45:56 PM »
Taller tires front and back is the quickest and probably easiest/cheapest.
How close are you to Rocky Mount ? Send me a pm

Offline wideopen231

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Re: gaining ground clearance.
« Reply #2 on: January 23, 2021, 07:25:27 PM »
 Changing tires is probably most expensive. for me anyway. Tires I have are almost new. Taller tire in 14 wide hard to find. Front tires would require new wheels plus limit ablity to get spare in case of. Easier yes. Would like new lighter front tire and wheel combo,but keeping same size gives me ready made spares. On rear I would like to try some `12 wide but still need new wheels for that and a 33 tall in 12 wide almost nonexistent

Cutting.welding and machining only cost few materials(very few in this case and time. While time is valuable I can find it easer than money. Skipping TV or sleep cost nothing.LOL Changing chassis is probably most work,but seems to be best since corrects issues and gives room for changes. Would like better option bur having hard time coming up with one.
Relecting obama is like shooting right foot because it did not hurt enough when you shot left foot

Offline masracingtd1167

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Re: gaining ground clearance.
« Reply #3 on: January 24, 2021, 05:28:33 AM »
Chris I have been running that 12x33 M+H on my car and have had great luck with them ! They are heavier than the Good Year 30 lbs but have been quicker for me in the 60 ft ! I will measure the roll out today and let you know what it is !     

Offline Paul New

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Re: gaining ground clearance.
« Reply #4 on: January 24, 2021, 07:14:18 AM »
M&H makes a 12x33-15
Brand:M&H Racemaster
Manufacturer's Part Number:MHR-069
Part Type:Tires
Product Line:M&H Racemaster Drag Race Slicks
Summit Racing Part Number:MNH-MHR69

Wheel Diameter: 15 in.
Tire Size: 33 x 12.00-15
Sidewall Style: Blackwall
Tire Construction: Bias-ply
Tire Diameter: 33.00 in.
Section Width: 15.90 in.
Tread Width: 12.30 in.
Minimum Recommended Wheel Width: 11.00 in.
Maximum Recommended Wheel Width: 13.00 in.
Directional: No

Offline masracingtd1167

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Re: gaining ground clearance.
« Reply #5 on: January 24, 2021, 07:57:12 AM »
I just measured mine and they are 99  3/4 roll out at 5lbs !

Offline wideopen231

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Re: gaining ground clearance.
« Reply #6 on: January 24, 2021, 03:55:49 PM »
Not exact but quick math tells me its 32 tall at 99.25. That would give me 1/2" more clearance.

 Bill.
Are you getting better wheel speed control with M-H/ If memory serves you tried M/T's and did have much luck with them. I Know Frank Parks don't like the M/T's. If mine don't work out I might give M-H's a try.  Looks like they are about same weight as 15x32x14 Mickeys I have now. I would need new wheels but 2" less wheel would be weight savings in 2 ways/The wheels and pocketbook. LOL

As for front ground clearance I am actually not bad .Problem is at mid plate. Front has about 3.4 at nose.Mid plate is about 1 to 1.5" lower than planned.Tire is part and chassis builder gets blame for rest of it. But to his credit its first dragster chassis he has built from ground up.LOL

 I could change upright and plate all in one and keep wheelbase at 225 and motor at 50" out. I think added welding in same area would actually weaken car. Loosing a 1" in those numbers probably very little effect. I think the extra 1" clearance would allow for more tire choices. If the 33's work I would have 1.5 more and be around 4" at motor plate. Another upside would be easier to get jack under car,but the old guy who does all the work is bound and determined to have a set of pro jacks or knockoffs that he built.
Relecting obama is like shooting right foot because it did not hurt enough when you shot left foot

Offline JrFuel Hayden

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Re: gaining ground clearance.
« Reply #7 on: January 24, 2021, 10:57:01 PM »
The easy way is taller front and rear tires , One of our JF teams has a John Worm chassis that also had a clearance issue , motor sits low in the chassis, like the pan is 5-6" below the lower frame rail. He now runs 33x10.5x15 MT , but I think the MH 33x12x15 would work better [ 101" roll-out] and he runs Hayden 18" front wheels , 250x18[ 23.75" ]tall rib tires, I also have 275x18 [ 24.25" tall] and 300x18 [25"] tall] . I don't like the look of the 300x18, it's a tire I sell to "T" bucket wheels. Or you can change the angle of the rear end, like one of John Worm's guys did, and change the front axle.
Your combo might like the 33x12 MH, we have a few JF teams running them and some blown BBC and SBC guys . Or you could step-up more and run what the fast A/F guys do run the M/T bubba 16x16 tires , the fast guys are runnning in the 5's, on injected nitro and the fast blown alky are running 6.00's on the bubba's
Let me know if you want more help.
Jon 805-444-4489, cell   
Jon C. Hansen

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Offline wideopen231

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Re: gaining ground clearance.
« Reply #8 on: January 25, 2021, 09:15:52 AM »
I plan on getting a set of wheels from Jon , but I don't plan on bigger ones. Since its so far from front axle to mid plate the 1/2" or so raise at axle centerline would be very little at mid plate. Help yes just very little. Bigger back tires would work better since only 50" to mid plate.Not sure about going to 2" bigger tire to get 1" plus  I feel is needed. That would add 6.28" to rollout. Probably need more gear,but since I don't have a base tune yet that may or may not be issue to consider. Which tire works best on back is big question. While I have a Hemi it is small by todays standard with only 482 cubes.I have to work towards smaller than standard bracket car tire. Oh so I thoink right nowmthen what the heck do I know,I built chassis to low to start with.LOL

 As always money is a consideration. With long list of pieces for car and trailer I have and the fact lottery folks keep pulling wrong number. I think cheapest route and probably best end result would be to simply lower rearend in chassis unless there is a negative effect I am not seeing. More work but almost zero cost.
Relecting obama is like shooting right foot because it did not hurt enough when you shot left foot

Offline masracingtd1167

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Re: gaining ground clearance.
« Reply #9 on: January 31, 2021, 09:06:38 AM »
Sounds like you might be better off changing the chassis and that way you can use any tire you want !My 33inch M+H tire has only 99 3/4 roll out and I don't think that would help all that much !

Offline wideopen231

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Re: gaining ground clearance.
« Reply #10 on: January 31, 2021, 01:33:38 PM »
Bill. I found same issue with my M-T 32s. According to roll out numbers the tire diameter is not as advertised. I could say that is  part of my issue, but ultimately it falls back on the chassis builder. He is same guy as, engine builder, crew chief, driver, owner and sponsor. Dang no wonder I am tired. LOL   Hey live and learn. I learned that pushing the limit not always best. I will still do it again, but I learned I shouldn't.
Relecting obama is like shooting right foot because it did not hurt enough when you shot left foot

Offline Curly1

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Re: gaining ground clearance.
« Reply #11 on: February 16, 2021, 06:41:24 PM »
Not sure what you are wanting to do and why? Is your motor hitting? Are you having problems hooking up? If you raise motor you also change center of gravity and weight transfer which may make it worse.
What is the engine angle?
You may be able to lower rear end only and mid plate to match, that gives you more ground clearance all way down chassis.
If you like the front tires can you change the front arms to raise car some there?
The ground clearance problem is one of the reasons I am going back to an altered.

Offline wideopen231

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Re: gaining ground clearance.
« Reply #12 on: February 17, 2021, 03:27:21 PM »
Not raising engine. I am actually lowering it to match rearend. All I need there is little shallower pan and was planning on building new one anyway. Could angle engine,but don't like idea and as stated in other thread here it has very little to no effect with tires we have today. In 1965 might have had big effect. I like the low to ground look, but does make driving around crappy pit roads a pain and loading and unloading can be difficult.

As said earlier frontend is fine its 3.5" as is. I am going with some new bolt A-arms and figure to build two sets with 1" difference in height and possibly different stagger.
Relecting obama is like shooting right foot because it did not hurt enough when you shot left foot

Offline wideopen231

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Re: gaining ground clearance.
« Reply #13 on: March 06, 2021, 03:29:55 AM »
Only gained 1.125" at mid plate. While only 1.125" it is about 50% increase,sounds better and made ton of difference in loading the car, Good amount of work but I think will be worth it. Now if I do go to taller tire  this year I will have even that much more and if I had to drop a inch in tire .I will still be better than I was before.Litlle room for change is good I hear.
Relecting obama is like shooting right foot because it did not hurt enough when you shot left foot

Offline BK

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Re: gaining ground clearance.
« Reply #14 on: March 09, 2021, 07:19:49 PM »
Not raising engine. I am actually lowering it to match rearend. All I need there is little shallower pan and was planning on building new one anyway. Could angle engine,but don't like idea and as stated in other thread here it has very little to no effect with tires we have today. In 1965 might have had big effect. I like the low to ground look, but does make driving around crappy pit roads a pain and loading and unloading can be difficult.

As said earlier frontend is fine its 3.5" as is. I am going with some new bolt A-arms and figure to build two sets with 1" difference in height and possibly different stagger.
I thought about spreading the mounting tabs for my A-Arms and then making spacers so I could move front wheels forward or backwards for different stagger.