Engine options

[stockcar5]

Purchased a late model a couple of weeks ago. It's a 2012 mb custom with 2016 updates. Looking to build a motor for it. Right now I'm thinking along the lines of a 3.5 stroke 360 and looking to use a posted profiler head. Hoping to make 550-600hp. Motor will have roller cam, shaft rockers ect. What are your thoughts?

No rev limiter and tire is a d55, no grooving or siping allowed. All cars run an 8 inch spolier.

Motor I'd like to build would fall under option F

OPTION A: 602,604 GM crate Motors, 2200 lbs weight minimum

OPTION B: GM ct525 minimum weight 2300 lbs minimum

OPTION C: Complete IMCA Spec Motor rule weight 2300 lbs

OPTION D: 364 or smaller all steel engine with compression ratio 11 to 1 or less must weigh 2325 lbs

OPTION E: 364 or smaller all steel engine with compression ratio greater than 11 to 1 must weigh 2375 lbs

OPTION F: Chevrolet Motors under 364 cu inch motors with standard valve angle(23 degree) ported steel or aluminum heads must weigh 2375 lbs

OPTION G: Wisota Spec motor must weigh 2375 lbs

OPTION H: Chevrolet Motors 365 cu inch through 410 cu inches motors with standard valve angle ported steel or aluminum heads must weigh 2450 lbs and 1 1/8 restrictor.

OPTION I: 411 cu inches or greater with steel or aluminum heads must weigh 2450 lbs and 1 inch restrictor. (unrestricted valve angle)

OPTION J: Open aluminum or steel motors with unrestricted valve angle 365 cubic inch or less must weigh 2350 lbs with 1.250 restrictor.

OPTION K: STEEL BLOCK ONLY: Chevrolet motors over 364 cu in with standard valve angle plus or minus 2 degrees of standard ported steel or aluminum heads. Must weigh 2350 lbs with (4 ea) 1.100 restrictors. (SLMR section 12 item 6) approved by CC 4-2-18

1. Aluminum Blocks must add 50 lbs in front of motor plate.

[grt74]

b would be hard to pass up

[stockcar5]

I'm not a crate guy and I have about 1/2 the parts for a good 360. Should have mentioned that. The ct525 is a cool engine IMO but I have nothing for an LS motor so that could get spendy quick.

[Austin34471]

Purchased a late model a couple of weeks ago. It's a 2012 mb custom with 2016 updates. Looking to build a motor for it. Right now I'm thinking along the lines of a 3.5 stroke 360 and looking to use a posted profiler head. Hoping to make 550-600hp. Motor will have roller cam, shaft rockers ect. What are your thoughts?

No rev limiter and tire is a d55, no grooving or siping allowed. All cars run an 8 inch spolier.

Motor I'd like to build would fall under option F

OPTION A: 602,604 GM crate Motors, 2200 lbs weight minimum

OPTION B: GM ct525 minimum weight 2300 lbs minimum

OPTION C: Complete IMCA Spec Motor rule weight 2300 lbs

OPTION D: 364 or smaller all steel engine with compression ratio 11 to 1 or less must weigh 2325 lbs

OPTION E: 364 or smaller all steel engine with compression ratio greater than 11 to 1 must weigh 2375 lbs

OPTION F: Chevrolet Motors under 364 cu inch motors with standard valve angle(23 degree) ported steel or aluminum heads must weigh 2375 lbs

OPTION G: Wisota Spec motor must weigh 2375 lbs

OPTION H: Chevrolet Motors 365 cu inch through 410 cu inches motors with standard valve angle ported steel or aluminum heads must weigh 2450 lbs and 1 1/8 restrictor.

OPTION I: 411 cu inches or greater with steel or aluminum heads must weigh 2450 lbs and 1 inch restrictor. (unrestricted valve angle)

OPTION J: Open aluminum or steel motors with unrestricted valve angle 365 cubic inch or less must weigh 2350 lbs with 1.250 restrictor.

OPTION K: STEEL BLOCK ONLY: Chevrolet motors over 364 cu in with standard valve angle plus or minus 2 degrees of standard ported steel or aluminum heads. Must weigh 2350 lbs with (4 ea) 1.100 restrictors. (SLMR section 12 item 6) approved by CC 4-2-18

1. Aluminum Blocks must add 50 lbs in front of motor plate.

I want to know who assembled a group of cars with all of these engine combos and tested them (same chassis, track, and driver to eliminate variables of course) and dialed in these restrictors and weights to equalize the field. Must have been quite the experiment

[Basecircle]

That IS quite a variety of combinations. Is it an established class that’s been running a while, or something brand new? If it’s been around, what’re the front running cars using? Is there a noticeable motor difference on the track, or just handling? Some tracks motor just isn’t that important. If you already have parts, your decision is easy unless you feel you’ll be at a big disadvantage.

[stockcar5]

This will be the 3rd year for the series. The wissota package is popular mostly so guys can race local wissota sanctioned tracks. I dont plan on doing any wissota stuff. wissota motors tend to be in the 600-625hp range.

[Krooser]

I see alot of wissota engines every week... amazing how some are so much better than others... I'm sure there's no cheated up motors!?!

Wissota spec heads are pricey... buy some used or build the best engine you can with what you have.

[hucktyson]

Imagine that .... untouched d55’s .... 🤔 now make that Lucas and woo rules , mark the 4 tires at the beginning of the weekend and you run the same 4 all weekend including the A main ....

[cjsracing]

I want to know who assembled a group of cars with all of these engine combos and tested them (same chassis, track, and driver to eliminate variables of course) and dialed in these restrictors and weights to equalize the field. Must have been quite the experiment

It's the SLMR series in Nebraska and Western Iowa. Joe Kosiski assembled the rules.

[billetbirdcage]

If money is no object, I'd go with E. That being said, no way I would spend that kind of money but there is one that does that I know of. Again I'd only go with E, if your unlimited on budget to take full advantage of it otherwise it's probably not worth it and other options that would be better.

[stockcar5]

E would be good but yes it would get very expensive to do it right. Thats why I liked option F. Same weight but with the advantage of less front end weight.

[Krooser]

Shawano has several engine options, too. 602, 604, IMCA modified, Wissota LM, open motor with iron block. Nothing over 410 ci. No aluminum blocks.

Most engines are Wissota or open (with restrictor plate).

Seems to work pretty good.

[riddle28]

the way its wrote, looks hard to beat the 525 on power and weight but their reliability is questionable. a stock 3.48" short block with good head and cam should make 550 easily

[Doc88D]

As a racer that has had one, option B is the best way to go. You may not have any LS bolt ons, but by the time you buy headers, fuel/steering pump, carb & ignition you are still at or below 10k TOTAL! You cant build anything for that with that power and super smooth drive ability. Plus they are going to let you weigh less than any other option (exception to the crate).

When they 525 first arrived on the scene in the south they were allowed to run with supers with a 100 lb weight break and a 10" spoiler. In that first year William Thomas and Ronnie Johnson went on a win streak of good paying super races. this infuriated car owners with 30-40k super engines. The following year they took away the spoiler making them run 8". The 525 still won enough open competition races that they soon put it on the same weight package as the open engines.

With all of that being said. Option B is a no brainer.... You put it in, keep the oil and filters clean, and run it at 7200 rpm. The rest of the time you get to spend on working on your set-up...

[Austin34471]

If money is no object, I'd go with E. That being said, no way I would spend that kind of money but there is one that does that I know of. Again I'd only go with E, if your unlimited on budget to take full advantage of it otherwise it's probably not worth it and other options that would be better.

You’d go with an all steel motor over a 525 with no lead in front of the engine plate? I bet a 525 is 200# lighter lol and gets a 75# weight break.. You better be able to make a bunch of power with that thing

[hucktyson]

It says aluminum
Blocks 50 pounds in front of the mid plate ... a ct525 is an aluminum block

[Austin34471]

It says aluminum
Blocks 50 pounds in front of the mid plate ... a ct525 is an aluminum block

Missed that. Thanks

[SLM98]

Not SLMR. Tri-State Series out of South Dakota. Good rules package.