Monster - 1974 GMC Suburban 2500 Super Custom

[kikkegek]

Sold my engine 10 weeks ago and finally could rebuild the small block I had bought a year ago.

1970 Short block 3970010 casting, bored over .030 and honed
14101083 heads with 64cc chambers for some extra compression
Comp Cams XE250H-10 camshaft
Sealed power Pistons H345DCP30
Cloyes double roller chain 9-3500TX9
Edelbrock Torker II intake
600cfm throttle plate with IMPCO 425 propane mixer
CB Performance Black Box (fully programmable ignition system)
new oil pump
replaced the v-belts with a 93 C1500 serp-system

finally finished my build and got around to starting the engine...

dont mind my Dutch comment

http://youtu.be/bH2MqekWXi4

after breakin in the engine for over 20min. I tried driving it. It had absolutely no power at more then 5% of the throttle and vacuum dropped allmost immediately when increasing throttle. Vacuum at idle was just a poor 10-12inches.

after some research, pulling the intake and watching the valves while turning the balancer I found out I had the camshaft wrongly aligned

there is a inner and outer ZERO on the small sprocket. I aligned it using the inner ZERO....dooohhhhhhhh!!!!


see where it is about 20-30 degrees out of alignment


this is correctly aligned


started the engine again and idle was at 18 inches of vacuum and idle quality was very smooth

http://youtu.be/iQVNYHc4s2g

at first I used a gasket without a exhaust crossover, but the exhaust just blew right through:


so searched a little online and found a guy that had stuffed the crossover in the intake with aluminium foil and cut some blocking plates from a tin can.









drove it for over 100 miles now and the intake has not changed a bit in color. Guess the block off is working




final assembly
with air filter on


without


and pictures of the bare engine


first mileage I got was 1:4,16 driving 100 kph over 100 miles

previous engine with performer cam from Edelbrock and dual plane intake got us only 1:3

I did notice the engine gets pretty warm on 100kph speed....105-110C

added my 5HP stickers from CB Performance and Comp Cams ofcourse


will report back here....but so far, so good!

oh and a nice pic with my dogs

[68Timber]

Nice progress! How do you like that cam and intake?

[kikkegek]

Originally Posted by BRUISER

Nice progress! How do you like that cam and intake?

so far so good. the single plane intake is perfect for propane and the cam was bought with a focus on torque.

I notice power has moved down in the rpm range, but I have not floored it yet. I want to slowly break it in for about 300 miles...