427 stroker build

[ProStreet71]

Hey guys, I am helping my buddy build a 427 sbc. He got a good deal on a new Dart Little M block. $1500!!!! We are searching for parts at the moment. Marv gave some great advice in another thread on this same subject. Now the question is, are these blocks ready to use? Do they need any final machining? I am sure it will need to be finish bored for what ever piston we use. Will probably deck to "0 deck". Will it except a 4" stroke without clearancing? Thanks for any help!

[nxtruck]

Congrats on the good find!
It will have to be fitted to your pistons. I've heard that some of these blocks need the line bore checked, as well. I believe that these blocks are clearanced for a 3.875" stroke max., but there's plenty of meat to clearance it for the 4" crank.
I'm sure others will chime in with more info. Good luck on the build!

[ProStreet71]

Ok we have decided to build a 434 rather than the 427 to make sure the cylinder is bored perfectly straight.

[Marv D]

To get the bore cleaned up and put the right finish on the wall for the rings your running is a good move. That block will go to 4.200 bore no problem so there is no issue as far as meat on the wall, but if you can keep it to +.010 or +.020 will serve you well in the future. Pistons start getting harder and harder to find after 4.165.

I'll again offer the suggestion on rods, OLIVERS or Lunati ProMod rods will save you a LOT of headache as far as clearance to the cam and block. No one can anticipate the rod your going to stuff in there so you can almost plan on 'some' clearancing... the trick is to remove ONLY as much as is needed and no more. The 'norm' is 0.050" clearance to everything,, I use 0.035" and have never had a problem. As a wise old engine builder once told me...

"0.050' offers a bit of a comfort factor don't you think? As long as it clears and you give a touch extra for stretch and expansion,,,, what more do you need?

Well I ain't quite that brave,,, 0.035" works for me (just happens to be the thickness of a standard paper clip so you have tons of readily available 'guages' to bend up and check clearances in those hidden places)

For clearancing the block, a carbide burr in a air cut-off works quick and clean. If you have to clearance the rods for cam lobe clearance,,, take the MINIMUM off you can and use a belt sander clamped in your vice with a 100-120grit belt ,,, works smooth and clean. Then polish ALL cuts with a green scotch-brite pad in your cutoff, or a fine flapper wheel. You want to make sure and remove any stress risers from sharp angles, bumps or ridges. It's best to clearance the motor THEN take it to be balanced, but,, you have to take a heck of a lot off a rod to equal a gram (about the same volume as a 1/4" x 20 nut)

If you use a lesser rod like the Eagles or another H-beam,,,, be sure you clearance, then have all the rods weight matched, THEN balance.

Another suggestion... just PLAN on using high ratio rockers. In my little Nova 434 I'm running 1.7 exhaust and 1.8 intake ratio Jessel shaft rockers. The smaller the lobe, the easier it is going to be to clearance in the cam tunnel. Depending on what head, power level and all you choose,, you are going to want LOTS of lift. Todays cam tech is for short duration, oooodles of lift, and set the valve timing to compliment the use / package. Custom cams are the only way to go these days when you have packages from guys like LSM or Jay Allen (Caminnovations) who will design your roller cam, have it ground, cam Dr'd and delivered to you for less than $400 Power is well worth the few extra bucks.... trust me

[ProStreet71]

Marv, thanks for the advice! This is our first stroker build so all info is appreciated. This will be a street/strip type motor with more emphasis on the strip part. Compression will be in the neighbor hood of 10.5-11:1. He has a set of Brodix -11 that have been professionally ported. Dont know the flow numbers off hand, but I do remember peak flow was around 300 at about .650 lift I think. The heads were on a 406 in a 4200+ pound 79 Chevy truck that run 7.0's all day long in full trim just like it came from the factory. This truck is awesome! (it now has a 434 running 6.80's and still tuning) Thanks again!

[nxtruck]

Originally Posted by ProStreet71

Marv, thanks for the advice! This is our first stroker build so all info is appreciated. This will be a street/strip type motor with more emphasis on the strip part. Compression will be in the neighbor hood of 10.5-11:1. He has a set of Brodix -11 that have been professionally ported. Dont know the flow numbers off hand, but I do remember peak flow was around 300 at about .650 lift I think. The heads were on a 406 in a 4200+ pound 79 Chevy truck that run 7.0's all day long in full trim just like it came from the factory. This truck is awesome! (it now has a 434 running 6.80's and still tuning) Thanks again!

This 79' Chevy truck you speak of sounds pretty impressive! Do you have any other info about it, like swb or lwb, trans, tires, gear, info about the motor, etc.?

[ProStreet71]

Nxtruck,

The 79 I speak of is indeed an impressive truck! This is the truck that started my quest to get 7.0's with my 406 powered 71 swb. He drives this truck 25 miles one way to the track, takes his street tires off and swaps to a 10 slick. Also takes his tailgate off after he gets to the track. This thing doesnt even have an aftermaket shifter. He still shifts with the factory column shifter and is deadly. He gets in the money almost every weekend.

I only know bits and pieces about this truck. Old motor is a 406. Heads were ported -11 Brodix. Cam was a solid roller Comp extreme energy, cant remember the specs. If I recall, it isnt listed in the catalog, you have to look at the master lobe catalog to find the specs, but they are the extreme energy lobes. Do not know what the compression was. I know the heads are 66 cc chambers but dont know what piston he was running. Victor Jr intake with old 750 holley. Hooker super comp headers.

New motor is a 434 that ran a 7.01 first pass. I was mistaken about the 6.80's ET. He got it down to 6.91 with tuning and good air. There was only 2 weekends left of the track being open when he got this motor running. It dynoed like 640 HP I think. The heads are the new Brodix CNC heads. Not sure which ones they are thow. He was gona go with the AFR's 227 but didnt want to run shaft mount rockers. Intake is a Super Vic with the same old holley 750 and a HVH Super Sucker 2" spacer. Same hooker super comp headers. Cam is a Comp extreme energy solid roller.

UPDATE.... Changed cams to an unknown grind and changed carbs to a 1000cfm Quick Fuel. Put it back on dyno and made 667 HP!

Oh yea, it is a swb truck. The truck is beautiful! Still has everything that it came with from the factory except for A/C I think. Full interior and all. As far as i know it has stock suspension with Cal-traks, and 4.11 gear. Not sure about the trans or stall speed. Although he did send his converter off to get it tweaked on over the winter. So with the cam, carb, and converter change I think he will get in the 6.80's now. Hope this is enough info for you, its about all I know.

[nxtruck]

Thanks for all of the info!!
Sounds like a money-winner on the street! This story reminds me of a guy I know that had a 79' Chevy swb truck, also. He had a fairly tame 400 sbc with a B&M mini blower on it. He would drive this truck to the track and swap his street tires for some slicks that he carried with him and run 8.00s to 7.90s and still had all of the factory equipment, including the A/C. Before he had the truck, he had a mid-70s 1/2 ton Suburban with this blower motor in it. You shoulda seen the looks on kids' faces when their late model Mustang would get left at a stoplight by this rusty old Suburban!
Thanks again for the info!

[85sqbdy]

great deal on the little m. been runnin a little m for 4 years now with no problems. good rule of thumb though clean, clean, and then clean some more. when i got my block home i stood it on end and some casting sand fell out of one of the water jacket. not much, but enough that i went through a whole bottle of detergent cleaning it out. i built it with a lunati crank and rods, wiseco pistons, howaards billet solid roller cam, dyno'd at 725hp. get that vehicle weight down and you'd be surprised. originally had it in a 3200lb nova running 6.10's. then found a 2600lb s-10 and now runnin 5.40's. this year will be freshening it up though. may go bigger, but right now the combo's working great. the tune's just right and deadly consistent. little m's are a great foundation. keep us posted with some time slips.