[chiphead]

Guys,

I got myself into a real fine mess this time. I volunteered to help some co-workers with a dirt-cheap mud bog truck project. Its a 1988 Toyota 4WD powered by a chevy 305.

It's about worn-out but its a 1st year starter project. Its got a 600 CFM 4160 carb and a MSD style HEI. What kind of main jets and timing curve do I need? It's got no power. The first time we put it in the mud, at WOT, it would go to 2000 RPM and pour black smoke. Would barely turn 35" boggers over before it died.

And whats the secret to re-locating the radiator? These guys put the radiator in the bed with electric fans. No room up front. Of course it runs hot. How should we plumb the radiator in the bed? Stock snake-belt accy system and reverse rotation water pump.

These guys expect me to save their bacon....Help!

thanks!

chip

[b-man]

With the radiator in the bed, make sure that the top tank of the radiator is higher than the cylinder head(s).

If that's not possible, add a reservior tank (example: older Ford 352/390 FE engines had one) that will accomplish the same thing, it will keep the water level high enough that you don't end up with air pockets in the head(s).

I would use copper plumbing pipe/sweat fittings for the main piping with sections of rubber hose where you need flexible connections.

I did a similar type of radiator remote mounting, I had a '64 Buick Special 225 V6 in the back of a '69 VW Squareback. The radiator was mounted up front where the spare tire normally sits, I used copper tubing/rubber hose along with the Ford reservior tank since the upper radiator tank was lower than the heads.

It ran plenty cool after adding the Ford tank, it was a Stanley Steamer before adding that tank. It used a stock water pump and a pair of aftermarket electric fans, I built this contraption back in 1978.

[zbuickman]

well what kind of Axle gear ratio? 4 hi or 4 LO Heavy clay. Those boggers BITE youll need a lot of power to spin them things. stock Toyota axles?? if so you wont have them for long with the boggers. Lets put it this way 35x12.5 boggers with a stockish 305 is going to require @4:56ish gear ratio 4:11 minimum. Ill trade you some wore out (1/2" deep tread) BFG MT 33x12.5/15's for those boggers. they would be better suited to that truck. how does the truck run on the street?? work on the drivability fist and if it can handle that take it esay in the mud. light mud and worn tires. and build from there. sounds strange but it sounds like its under powered BAD. those boggers BITE

[zbuickman]

oh yeah lets put it this way My truck with a stockish 454 3:73 Gear would hardly spin over a 35" bogger

[chiphead]

Truck runs OK on the street. Out of tune for sure. He had the TH350 in low, and the transfer case in 4L. Stock toyota front and rear axles. No power, overheated, engine rattles when revved. We hit 250F in the staging lane. We put it in the mud, held the pedal to the floor until it stalled. Shorty headers turned upside down with 3 foot tall stacks. Sure blows some purdy smoke rings.

305 is not long for this world, for sure. But I'd like to get the cooling and tune right so we have some fun before it blows.

How should we plumb this thing with a crossflow radiator? 1 1/2" copper plumbing? sounds expensive

[zbuickman]

Originally Posted by chiphead

Truck runs OK on the street. Out of tune for sure. He had the TH350 in low, and the transfer case in 4L. Stock toyota front and rear axles. No power, overheated, engine rattles when revved. We hit 250F in the staging lane. We put it in the mud, held the pedal to the floor until it stalled. Shorty headers turned upside down with 3 foot tall stacks. Sure blows some purdy smoke rings.

305 is not long for this world, for sure. But I'd like to get the cooling and tune right so we have some fun before it blows.

How should we plumb this thing with a crossflow radiator? 1 1/2" copper plumbing? sounds expensive

cracke HG cracked head. you have some thing going on there. to give an idea of the power those boggers need. stand back and look at that truck can you honestly see it going out in the steet mash the gas and and do a Top fuel style burnout. on toalally dry somewhat coarse pavement. if not you dont have enough power to spin those boggers in the mud. and yes the copper tube is probably the cheapest way to go. also make sure the rad isnt plugged. also if the truck was that hot in the staging lanes. its not going to have any power. Im not tring to be the bearer of bad news just tring to help you out

[chiphead]

Any idea on what carb jetting I should go with? They've got a holley red pump deadheaded into a cheapo regulator. What kinda fuel pressure is correct for a 4160?

I'll do a compression test to check for blown gaskets. Any idea of a timing curve?

Anything special when putting a carb intake on a 1988 TBI 305 engine? This whole truck is so frankenstien.

[PONTIAC DUDE]

If ya need help PM or e-mail me. we quite a few of em down this way.


http://www.youtube.com/watch?v=WRzpPXqFrqk


Just a lil ole Dude built 572 BBC.

with lil ole 54's on it.

[chiphead]

Will common carburetor intakes fit a 1988 305 engine that had TBI? I don't know much about parts interchange with SBC. Imagine that!

I think those guys stuck a single plane intake on this 305. Doesn't a mud truck need a dual-plane for torque?

[zbuickman]

yes and no a true race truck would run high RPMs and use a single plane yours probably needs a dual plane. Im not sure when the TPI enginse went to the centerbolt valve covers but I think they use a special intake. and if it is a stockish 305 a dual plane would definatly help some on the low end @ 2000rpm where you said its having a problem. as far as answering the other Questions you had and so forth you may have a powervalve size issue at that low of rpm and load. and for the Distributor what did it come out of????hard to say what to do with out knowing where your at. good luck

[zbuickman]

To add to that the 305's Ive dealt with dont like alot of timing. usually cobled up junk. but on a 305 Id start at @ 32° in at 23-2500 and about 6° base. but if it drives ok on the street your pobably pretty close. try the intake first