The elusive 224/3.7 MerCruiser banger

Thanks Gear for the advise. I know it's sacred ground here and that is why I asked. I pulled all the pics not related to nuts and bolts. Scott

 

We ran EFI early on and switched to Carb. I currently am running a carbed 1968 corvette 350/350. We have one of the oldest engines in the field. I am probably going with the early suggestion of Dawford of the buick pull thru turbo. With a Q-jet.

There is a Model T GT that runs Lemons and has been very successful. It's a Model T tub grafted to a Fox body chassis.

 

Scott,

The car I crew on at Bonneville has run a T-101 for quite some time with the exact gear setup you are using. They are quality pieces!

If you want to run your bellhousing you are going to have to shorten the back of the motor. Just this weekend I tried to get some super accurate measurements on just how much to remove from the back of the block. Unfortunately I didn’t have flexplates or flywheels to fit the Chevy and Mercruiser blocks. I did find that just measuring from the back of the crank to the edge of the bellhousing doesn’t get the dimensions you need.

You are also correct that the back of the crank will need to be machined for a pilot bearing.

If you have read this thread in entirety you have learned that building one of these motors is not as easy as it first appears. It can also get expensive.

I have a silly question. You are building with a $500 limit. Your transmission is worth at least 3 times that. How does that work?

 

Yes, we love it.... Especially on the up shift. The strait cut gears make it feel and sound like a real race car.

Yes, I am prepared for that. We don't expect it to be simple or cheap... We do expect it to be different. There are about a thousand Lemon cars running now and this is a combination that will be like no other. Plan is using the block and crank. Because of the rod piston combo we will be using some rods and pistons from a HiPo 460 that took a dump. Good buddy of mine owns R&E racing in Lancaster Ca and he has lots of trashed big blocks from customers and etc. Eyeing a set of Oliver Ti rods and JE pistons. We will use the aluminum head from another build, Cut a cam blank and install roller bearings. Solid roller lifters and T&D rockers, beehive springs, ti retainers. I will cut in half a Victor intake, weld up the plenum and adapt to: I got approval for the Pontiac 301 turbo system and we will top that off with a Holley 670 vac secondary that I custom built for road racing.

One of my biggest concerns with this build is the cooling capacity. The best lessons learned in this series is keeping the RPMs below 5K. Early on we built our engines (Small block Chevys) with "Drag specs". Marine builds are the way to go. Tourqe is the name of the game. You don't go faster with RPM you go faster with gearing. Then the engine survives. There has been over 200 Lemons races and only one time has a SBC won. They just don't live in normal build trim. Our last engine went 8 races. That is many thousands of full race miles with only oil changes. My estimate is this build will run in the 4K range. We do lots of dyno testing and I will surly share those numbers on HAMB. Like my first post implied I really want to hang on HAMB just on this thread. (Like Clint Eastwood said... "A man has to know his limitations") You all have provided a serious wealth of knowledge to me and I hope I can reciprocate some too.

Not a silly question at all. The rules state you can spend 500$ on the total build. You can buy a 3000.00 car and sell off 3500.00 of the parts. BUT: you have to document what you did. And prove it. The spirit of the rule is just that. When going through Tech you can openly bribe the tech guys when they are assessing the build cost. How I got the trans was a plead for what many guys run... A T-5. I demonstated that to even find a J-Y SBC bellhoused T-5 one would spend 500.00 and lie they got it for 50 bucks. Then, they would take to their local trans shop and spend another 600 on a "Freshen up", then spend 3 bones on a clutch and etc. Knowing this T-5 swap is a 1500-2K pass-thru I convinced the PTB I could sell my existing full manual 700R4 for 1000 bucks. Then I showed where I got a damaged housing and main shafts on e-bay for 200 bucks and could get used gears, bell house, T/O bearing and clutch pack off of ebay used from Cup teams selling parts it would cost less than a T-5 swap and 5th gear would never explode (Big issue with T-5).... I coupled that with the fact that since we had a 1968 Vette engine the proper trans would be a "Muncie Style" trans. The shifter (1000.00) falls under drivers comfort rule and is exempt.

These tech guys are no different than you or I. They know what is what when it comes to engines, suspension and otherwise. The one thing they are really good at is assessing the team. You can have the most power, totally cheater suspension and all the things on paper that would say... "Total Domination" but they know 4 ringer drivers in a basically stock Neon could mop a team in a brand new vette driven by 4 regular guys driving after 16-24 hrs of track time. They take that into consideration. The competition is very good. They also have 3 classes, A,B,C Class A is like what we run. B would be like a VW jetta and C would be like a stock Hudson Hornet. But the Hornet would win The big prize of "Judges Choice."

This is how we acquired the vette engine. Good story. http://blog.caranddriver.com/lemons...ne-swap-roulette-with-the-iroc-maiden-camaro/

 

I ran into a little problem last week that I haven't read about here before. I had the stock Mercruiser flywheel on the motor. I tried to install a GM car bell-housing. It almost fit. The flywheel teeth dug into the aluminum bell-housing. It would not have rotated. I have since swapped to the heavy truck bell-housing which was designed for a larger diameter clutch. Everything clears fine with it. The truck bell-housing has a larger hole which is used to register the transmission. There are 2 fixes for that. 1) use the bearing retainer for the truck 2) build or buy an adapter ring.
It may just be the part # of the bell-housing I used, but check your clearance.

 

Beck, I did a little research to add to your data and:
OEM 470 flywheel is 13-7/16" dia. 157T.
A stock SBC (less than 350ci) is 12-1/2" 153T
The 400ci SBC and BBC is 14" 168T

I don't know anything about tooth pitch yet.

 

Well, I got my block, crank and other bits on the way. I also found and purchased a pull through turbo system from an 80-81 Pontiac 301. Dennis' Toyota water pump deal sure is sweet. I love the solution. I think I might be doing a real trick piece for the front cover. Considering milling a whole new one that is two pc. It would have the P/S, Alt and water pump provisions in it and be for a dry belt... The cover section will have the provisions for the water pump and also the cam access cover for timing and add dist/fuel pump. I am an electro/mechanical/industrial designer and hope to put some of my skills to task on this.

My goal is 265HP @ 5100 RPM & 300ftlbs to the wheels. I think this power plant can do that.

CAM CORE... the ever elusive. Hook me up.

 

This is getting real interesting.
Good luck.Have fun.Be safe.
Leo

 

Everybody,

Beck gave me some dimensions for a cam blank. The guy that is doing the machine work on my QC sideplates has Computer Assisted Machining expertise and equipment. I have talked to him about cam blanks and he assured me that he can do these. But before I send him the prints, we would need to decide on a cam gear (or sprocket). Beck's has a SBC pattern, but that will probably require buying two timing sets to make everything work. There would be some leftover expensive pieces.
I think I have found some off the shelf pieces that would make a belt drive, using 2.3L Ford pulleys. Not sure I have the belt completely figured out.
What would you guys like?

And of course, how may would actually step up and buy a blank?

 

Totally....

http://www.ebay.com/itm/Ford-429-46...ash=item2ef1e9c5a9:g:gHQAAOSw5cNYNNXJ&vxp=mtr

However, I would absolutely pony up for the core maybe two. I just wish we could clearly nail down upper/lower/chain for the factory set-up. Then go from there.

 

My cam is going to be a bit different. I'm looking at something like this
http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=47&sb=2 but I'll use solid rollers and want this total lift and profile with 1.85 rockers.

 

Anyone want to go in halfies on a V8 set of rockers, rods, pistons, rings, bearings.... I want good stuff. Like JE/Scat/Clevite/Comp- I also see a stainless header that will work for me but I need the passenger side so the driver side would be good for you. Maybe a pair of CJ heads.

 

Not sure on bearings. I recall an Inliners article that said tangs on opposite side from V8

 

On the rods?

 

Anyone seen or in the know with roller cam bearings being installed on this block?

 

Just to get the ball rolling, I think we should look at having the front of the cam made like a 460 Ford. This would allow off the shelf timing components (as long as the center distance can be accommodated). It seems that a set made for .005" or .010"shorter center distance may be required. These are available.

At least we can get a ball park idea of what cam blanks will cost.

 

I agree, cam bearings... Could play a role in this. With the front cover I want to make I could take a std timing cover if we could drop the cam with roller bearings cut off set. (Lower) Does anyone know what the cam/crank separation is on the 470? I don't have my block yet.

6.078 460 Ford
4.804 SBF
5.152 BB Mopar
5.150 BBC -Also .400 raised- 5.550
4.521 SBC
4.885 LSX

 

Do you have the pass side header to this set?

 

Earlier in the thread I seen a book maximum boost suggested. I bought the book and another one from Amazon then also ran across this. http://www.volkspage.net/technik/04/maximum_boost.pdf

 

I don't think the 460 upper gear will work if we want to keep the shaft that originally drove the water pump. The 460 top gear mounts with a center bolt. Do a google search for a photo if you wish.
That eliminates the option of the water pump shaft or whatever you were going to use the shaft for.
If you planned to eliminate that shaft and plug the hole in the timing cover it would work.

 

Is the 2.3 Ford timing belt a wet setup? I don't see a way to easily seal the front cover if it is dry.

 

Most of aftermarket aluminum heads use slightly different rocker arms.
Check these out. No girdle needed.
http://store.yellaterra.com.au/cate...ets/ford/ford-v8-big-block.html?sort=priceasc
Anything less and you will need some support of some sort.
The other option is T&D. A little more expensive but top of the line.
http://www.tdmach.com/rockers.html

The heads are usually bought as singles on the aluminum BBF. A word of caution with all the aftermarket heads. The valves and springs are usually not of the best quality when buying an assembled head. It costs more but you have a better product if you buy the head bare and have the valves and springs you want installed, after checking out the machine work. Normally a slight cut is needed on the valve seats too. These things are mass produced for the minimum expenses.

 

My personal belief is 1.85 ratio rockers is too much. With a roller cam you can put so much more in the lobe, so 1.65 to 1.70 ratio is plenty.

 

I am trying to understand the 5/8" measurement for the bellhousing shortening to make the back of the block the same as a GM.

I installed a Ford flexplate that has the GM torque converter pattern on one of my 470's. (That part # was given way earlier in this thread) I measured the height from the back face of the motor to the converter mounting tabs. I then did the same using a Chevy motor and flexplate and measured it. The difference was very close to the 5/8" reported. I cam up with about .650".

Then I did the same using flywheels. I measured the stock Mercruser and a new Ford flywheel. They do measure the same height. I then mounted a Chevy flywheel to the Chevy motor. I took height measurements again from the back face of the motor to the face of the flywheels. I came up with about 1.050" difference. Not 5/8". I understand I messes something up, but what?

Is this not the dimension I should have measured? Should I have measured to the crank hub? I'm confused. I don't doubt the 5/8" measurement given here, but I am trying to figure out where I went wrong. I have spoken privately with members here who have shortened motors the 5/8" and installed manual transmissions and everything worked for them.

 

I think what you are referring to is the main bearings. They have tangs on top and bottom. They are made from the top half of the bearings from a 351C, which only have tangs on one side of the bearing.
It is cheaper to buy the bearings for the Mercruiser than to buy 2 sets for the 351C. Falconglobal and others sell them on Ebay.or direct.

FlyHiFlyLo, you commented about lowering the cam by adding roller bearings. Wow. That is redesigning the whole valve train geometry. That is way beyond me. If you lower the cam the lifters run lower. That may change/destroy the oiling of the whole galley.

 

Beck, I have a Tilton SBF Ti flywheel for this project now. This will allow ... I'm hoping the same starter solution. And still run the Tilton 7.25 clutch pack with Chevy spline. They show to be the 20oz imbalance. ??? Thoughts? When I get back to TX I will pull the SBC in the race car and compare to the 3.7 with the ''Same flywheel" and then we can add to your data.

Also, many of my Ford guru buddies are HIGHLY recommending cut the crank to the BBC rod journals do to the 460 being so large that the bearing surface speed is unreliable and a power robber. I still want to maintain the same stroke so the piston design stays the same as 460. I don't want to mess with the piston skirt/cylinder sleeve surface engagement and make it an unknown as the skirt will travel deeper into the cylinder. When we tweak with stroking LSx engines this always causes piston rocking and failure. Might not be an issue with this engine but lots of bucks went into the stock sleeve length.

Moving the cam bearings could be an issue with lifter placement.... But it can play into a common belt drive. I just got back to California for the holiday, and my block and other parts just landed in Austin yesterday. So for two weeks I have no ability to measure these things. Depends what the trade offs are. Lower cam... Longer pushrods. Longer push rods help with stress angle on the lifter bore and push rod. Could you pleasemeasure center of cam to center of crank?

Running a 1.85 or even 1.9 rocker could possibly allow the stock cam to be cut to a roller profile by keeping lobe lift to .260ish. One build philosophy I have always hung to... And this is my engine credo. The rounder the cam the better. Bigger valve, Higher ratio= less lifter and rod has to be lifted. Now I'm always building endurance so this is why I cling to that thought. However, I'm only looking for .500 total lift. I have run Hyd rollers and don't get good life out of them. I have found for my application solid is the way to go with a tight .005 adjustment.

The stock Cam Core- Running roller bearings and roller tappets will reduce the load on it. Also this cam core from what I can tell still maintains the 460 overall geometry. But half the load is removed between the bearing journals because it is only activating two valves rather than four. I think the stock cam core is strong enough for a roller application. Especially with short lobe lift. But the roller profile has to fit and turbo grind could pull the centers out of the grind-able window. Again... Has to be measured.

With Dennis' water pump solution I think it's best to ditch the stock water pump provision and move forward with a whole new cover... This cover will mimic the front of an engine block (Whatever timing kit lines up).

Well that's enough for now.... I'll try some front cover concepts today.

 

You'll need to get flywheel neutral balanced.

 

Okay... Thanks

 

It would be a whole new rear cover with seals, well for dry belt, then front cover that supports and seals the water pump. Additional provisions will be alt mount and PS pump mount.

 

This might be a solution, Mill back the side cover mounting bolt nub, add a stud, and add a retro-fit dog bone and fabbed retainer clip. Tighten it down with a nut, and use the stud to reinstall the side cover.